#12 - Condensation, Roof Ventilation and Building Science with Clarence Macalister

Jess Kismet (00:00)

Hello and welcome to the Building Sciology Poddie where we talk about better buildings to live and breathe in. My name is Jess Kismet and today my guest is Clarence Macalister. Clarence is both a builder and a scientist with a Bachelor of Environmental Science with honours from the University of Wollongong and he has been running his building company Ionic Construction for 15 years. At Ionic Construction, they specialise in loads of random and unusual jobs in Clarence's words and typically of a remedial nature.

Clarence has a particular interest in condensation management and has worked closely with the Australian Building Codes Board and the Master Builders Association, contributing to their condensation working groups and technical communities. Clarence has also teamed up with Dr. Mark Dewsbury from the University of Tasmania to develop and deliver training courses on moisture management. And with all of that background, we have got tons to talk BAL. So let's get into it. Clarence, welcome to the Building Sciology Poddie

Clarence Macalister (00:55)

Thanks, Jess Kismet. We certainly do have tons to talk BAL. So let's get into it and I'll leave it in your very capable and charismatic hands

Jess Kismet (01:03)

All right, so let's start at the beginning. Tell us, just give us a bit of an overview of your career to date. How did you get to be where you are now? Start at the start, please.

Clarence Macalister (01:11)

I

was going to save the world as an environmental scientist many years ago and then realised that working for the government was not my cup of tea and then started out in the building industry 20, 20 something years ago and I thought it would be a good idea to blend my scientific knowledge with building knowledge and save the world again by

being the king of energy efficient housing and for one reason or another that didn't work out the way I planned it. And here I find myself now, I suppose in many ways on the other end of the energy efficiency side of things and that's looking at the science behind condensation building, physics building, performance and all the things, I suppose that the other side of ⁓ energy efficiency that's not just BAL keeping people warm and comfortable. Cause I think

in my opinion, the energy efficiency side of things is relatively easy. Keeping the building warm is relatively easy. It's all the other stuff that goes with keeping people warm that's the tremendously complicated stuff. And it's, I was speaking to a colleague today and this guy's been in the industry for 50 odd years and...

and gave a fascinating talk BAL all these projects he did back in the 70s and 80s. And I was intrigued and he says, yeah, Clarence, I'm intrigued by the stuff you do with this condensation and stuff. And it's fascinating stuff. It's never boring, never boring.

Jess Kismet (02:42)

No, it really isn't.

So to summarize, basically you, you go and fix people's stuff ups.

Clarence Macalister (02:49)

Ah look part of it is fixing people's stuff ups. And it's interesting that people see the poor construction practice as a scourge on the industry, which it is, but in many ways, I've been able to flip that and say, well, if there is such poor practice in the industry, then there's certainly the demand there to fix that poor practice. And the amount of work I get from that is significant.

But the other side of it too, and this comes back to my scientific background, particularly in biology, ecology and so on, where experimental design is really important. And what we've got out there in the built environment is literally millions of long-term experiments going in all these houses where we can come back 20, 30, 50, 70 years later, whether we're looking at plaster rising damp, moisture, humidity, condensation, timber deterioration,

material durability, whatever it is, and we've got these ongoing experiments where if we can look at them in context, we can get this phenomenal amount of that says, we can see how buildings are behaving over these very long time spans with particular methodologies. I think that the interesting thing now is that the buildings might take 10, 15, 20 years for these problems to really sort of... ⁓

show up in a very significant or dramatic way. And if you look at the time we've been building with radiata pine frames, MDF engineered timbers, wrapping buildings up with blue stuff, sealing them up tight as a drum, we've really only got 15 years of that experiment, of the duration of that experiment. So maybe we haven't seen the worst of that yet. ⁓

And so by doing this work, the scientist in me comes out to say, let's have a look and try and put all this data together and see what we can find out. Which is fascinating.

Jess Kismet (04:48)

I think you must know,

Yeah working on all the remediation jobs that you work on, must just be learning something new every day and just have so much to say BAL the state of construction in Australia now and in the past. So I'm really, really keen.

Clarence Macalister (04:56)

I am. am.

no, that's right. And

that's right. just last week, I was looking at a bell tower in a church ⁓ in Cressy in Tasmania. And then two hours later, I was speaking with a heritage plasterer who was specially, who specially come out from England to do the lime plastering on another heritage listed, world heritage listed property at Wormers. so again, here we've got experiments have been going for

170 years with all this historic and then I get to speak to people BAL everything from where you can source Ewan pine logs to splitting shingles to Scottish methods of slaking lime and on it goes. So it's fascinating stuff. then building physics is all part of that as well.

Jess Kismet (05:49)

Wow, all right.

Yeah, absolutely. I keep saying to people, it's not building physics, it's just building. Like you have to take into account all of this stuff no matter what you're building. Like you can't separate the two.

Clarence Macalister (06:01)

Correct, correct.

And building physics is everywhere. It's just people just don't know it. Yeah, that's right. And as we build the houses tighter and tighter, these issues become more more relevant. ⁓ and look, and an interesting thing is this example of condensation. And people say, we take ⁓ a cold can out of a can of

Jess Kismet (06:07)

It's everywhere.

Yes.

become more and more, yeah, know, first and so.

Clarence Macalister (06:30)

drink beer, whatever out of the fridge and put it on the counter and it gets condensation on it. And this is only something Mark and I came up with, Mark Dewsbury and I come up with the other days. You get a can of drink out of the cupboard that's at room temperature. There is no condensation on the can that's come out at room temperature, but you get one out of the fridge, you get X amount of condensation, you bring one out of the freezer, you get a lot more. And what's happening now is we are...

creating that difference between internal and external environments where that difference is more and more and more significant. So where we've gone from taking the can out of the cupboard at the same temperature to taking the can out of the fridge at five degrees to taking the can out of the freezer at minus five degrees and consequently that visible difference is more and more obvious.

Jess Kismet (07:19)

That's a great analogy.

Clarence Macalister (07:20)

And it's a great analogy. this is the thing that I've

been doing this for years and we come up with better ways to explain this and help people understand it all the time. And that's great.

Jess Kismet (07:29)

Yeah, absolutely. So

let's get on to explaining roof ventilation because I know this is a topic that is currently top of mind for Australian builders, particularly in the colder climate zones where it's now a requirement to ventilate the roof space in a certain way. And I know that you and Dr. Mark Dewsbury have been doing some a lot of training recently on this exact topic. So could you please summarise it or give us a bit of an explanation as to try to simplify it, please?

Clarence Macalister (07:34)

Thank

Correct.

Yes, so look.

Well, look, I suppose there are many different ways we can come at it, but I'll try not to detour too much. And historically houses in Australia, if you had a corrugated iron roof, it had eight foot or 2.4 metre sheets of tin, which were lapped here, there and everywhere, very uneven. A lot of air would naturally flow through the roofs. We had gable ends, had eave overhangs. So air was naturally flowing through the roof. So only in the last 10, 15 years, we've had products like... ⁓

rendered foams and more rendered brickwork, wrapping our buildings up with a lot more insulation, a lot more blue paper, etc, that we've gone away from naturally ventilated roofs to less ventilated roofs just by virtue of the building practice. So in some ways, we're really just coming back to where we were 15, 20, 25 years ago. And...

I suppose there are a few really key points here. And one is that people say, come the building code board has thrown this stuff onto us as far as roof ventilation is concerned? This more or less is modeled on the British standard, which has been around for 20 or 30 years, BS 5250 for condensation management. This is very, very similar to the British standard for condensation management. That's the first thing. ⁓ And the...

And the second really important thing is steep pitched roofs, which now are nominated above 15 degrees, are naturally less prone to condensation and mould problems. So as soon as you're less than 15 or less than 10 degrees, the problems increase very, very significantly. And that is reflected in the building code in that the flatter pitched roofs, so we're talking...

15 degrees or 10 degrees and under. And that is slated for change in NCC 2025 as far as having a single cutoff point, not having the intermediate sort of zone if you like. ⁓ But it will still be a case of the flatter pitched roofs require a lot more ventilation. And that just reflects the natural risk associated with flat pitched roofs as opposed to steeper pitched roofs. Now, when we do our training,

And this was, I can remember the day very clearly when I was building my particular building and I had this brainwave and I rung up Mark and said, I've had the brainwave says, yeah, you've worked it out for yourself Clarence. That's exactly correct. 100 % correct. And what it is, is that water flows off and down steep roofs very, very easily. When you have a flatter roof, it's much harder for water to flow down a flat roof just because of gravity.

And the exact opposite or very similar to opposite works with humidity going up. So we have warm air and air with moisture in it, which is naturally more buoyant. And it wants to flow up. If you have a steep pitch roof, it flows up very easily through a steep pitch roof. If you have a flat pitch roof, flatter pitch roof, the ability for that moist, buoyant air to, a warm moist, buoyant air to flow upwards is exactly the same as

Jess Kismet (10:48)

Mm-hmm.

Clarence Macalister (11:11)

water trying to flow down, it struggles to flow up underneath the flat pitch roof. And we do this demonstration using coffee beans and flattened the steep pitch roof. And you can just see the light bulbs going off, everybody in the room going, get it, I've got it, I totally understand it now.

Jess Kismet (11:13)

you

So

you roll coffee beans down a pitch and see what happens. Yeah.

Clarence Macalister (11:28)

Yes, see,

love coffee. I'm not a coffee drinker, but a lot of people absolutely love their coffee. And as soon as you put coffee there, there you go. Coffee mug in your hand. I don't drink coffee. And as soon as people get the coffee thing, and we actually use another thing with coffee to understand how, ⁓ &Ms and then, no, but then the training would stop there and there because I'd be eating &Ms for the rest of the day. But anyway.

Jess Kismet (11:44)

Maybe you could use &Ms. Although they're not round.

shh shh shh shh shh

Clarence Macalister (11:57)

And they know I've been doing the training course, there'll be coffee beans in the room, no matter how hard we try to sweep them up. But I think trying to get these things explained to people in a practical way that they can visualize is really important. And the last few times we've done this course, we did through Design Matters National a few weeks ago, is we actually have ⁓ physical models of roofs. And so we...

We talk through different products, we talk through different principles, we talk through different assemblies and having these models, I think really helps people visualize how it all goes together and what it means as opposed to just a drawing. And that's something Mark and I are really big on is to get these concepts into people's heads, whether that's a designer, whether that's a builder, whether that's someone out there in internet land, that they can get these principles and they stick.

where they have these light bulb moments. And I think that's as big a challenge as the sort of technical building physics side of it is, is getting that message to people in a way that they can, it sticks in their head. ⁓

Jess Kismet (13:05)

Yeah, absolutely. Just turning

it into layman's terms and making it digestible for people is so important and that's what I try and do all the time.

Clarence Macalister (13:15)

Yeah, yeah. And that really helps. And the thing is, and we were having this bit of a bit of a conversation before, and I think there's so many parts of building industry, and you're obviously a very good communicator. And, and, and everyone has the thing they're strongest at, which really helps. and you, you use those strengths to really lift everybody else up. And there's a colleague of mine, Luke Davies, and we did a video BAL the blower door test and

to talk BAL the 50 pascals thing, we had five kilograms of sand on a square metre of membrane and measure out the sand with a scale poured on the membrane, look at the deflection on the membrane over a square metre. And when you see the 50 pascals of in an actual blower door test on the interior membrane, you can see an almost identical level of deflection on that membrane as to what you can see when you pour the five kilograms of sand in. And that really helps people understand.

the principle, you think, five kilograms every square metre, and that's what the membrane deflection looks like in real life in the Blower Door test. That's an idea I got off Jesse Clark at the Building Physics Conference, which I think you organised three or four years ago in Sydney. So...

Jess Kismet (14:20)

Yeah, all right. Yeah, that's a good visual. That's something I hadn't thought of.

Yeah, yeah, good one, good one.

So just going back, is there anything you can do to help people understand the ventilation requirements? Could you go through what they actually are and what builders actually need to do?

Clarence Macalister (14:44)

Okay, so look, there's a table in there. Now I'm sort of doing this off the cuff, but I'm 90 % sure it's table 10.8.3 in the housing provisions of the National Construction Code. So this relates to both class one buildings, which is a stand alone dwelling and also class two, which is an apartment and the habitable parts of other buildings. So basically anywhere that anyone's living in any building. Well, most, there are some exceptions. Let's not go into those nursing homes, etc.

But so table 10.8.3 is the key. And what it talks BAL is a, it talks BAL how many thousand mm per linear metre. So on a lower pitch roof, it's talking BAL 25,000 square metres per lineal metre, which is equivalent to, you just take all the zeros off, equivalent to a 25 mm continuous gap. And so it's...

That's a good rule of thumb. It's not a rule of thumb, it's actually a number. 25,000 square mm per linear metre equals a 25 mm gap. So you've got to think how, well, it is a fairly big gap, absolutely. And so if you think...

Jess Kismet (15:49)

That's a fairly big gap.

And is that depending on,

sorry, did you tell me, did you say what roof pitch that's for?

Clarence Macalister (15:59)

So that's the 10 degrees and less. 10 degrees or flatter, anything between zero degree or one degree and 10 degree, correct, needs to have 25,000 linear, 25,000 square meters per linear meter or equivalent to a 25 mm continuous gap on two long edges of the building. Now, ⁓ the other thing that's a challenge here is once we have a 25 mm gap,

Jess Kismet (16:01)

Yep. So, so yeah, low pitch.

Clarence Macalister (16:27)

There aren't many places on a building that have a 25 mm gap that don't have some form of mesh or covering or something to keep birds and dust and mice, etc out. So automatically what happens, as soon as we have the 25 mm gap and then we need to put some mesh in there, the mesh, a lot of the bushfire meshes, for example, will have less than 50 % open area of that mesh. So you get the sheet of metal and only half of that is actually holes.

So if you want to, you got double it, double and sometimes more, it depends on the mesh, depends on, let's take as a rule of thumb for BAL mesh, very roughly 50 % is open area. So you've got to have a 50 mm continuous opening ⁓ on two long sides of the building. And then we've got to think BAL things like weatherproofing. Then we've got to think BAL things like dust and leaves and crap getting in there, it's going to clog it up, how it's going to look. ⁓

Jess Kismet (16:56)

So you're going to double it. Yeah.

Clarence Macalister (17:26)

And if we have a building that doesn't have any eaves or eve overhang, how are we gonna actually fit that in there? So the design challenges around that, particularly in lower pitch roofs are significant. Now, if we're going to a steeper pitch roof, now I'm putting my head on the chopping block here. I'm almost certain that if you've got a steeper pitch roof, like a 22 degree pitch, let's talk project estate home type thing, spec home. ⁓

we only need to have a seven mm gap.

So what happens is when you have a steep pitch roof, like a 22 degree pitch truss roof, which is on many projects, spec homes, whatever you want to call them, the inlet requirement at the eaves or the lower level of the roof is 7,000 square mm per linear metre or equivalent of a seven mm gap.

which is very easy to achieve, 7,000 square mm per linear metre, okay? Which is equivalent to seven centimetres by 10 centimetres for every linear metre, which is equivalent to a continuous seven mm gap. 7,000 square mm per linear metre is equivalent to a continuous seven mm gap. So that's seven mm gap, that's pretty easy to achieve. That's less than

Jess Kismet (18:25)

Square millimeters or square meters?

millimeters. Yep.

Clarence Macalister (18:52)

a bed joint in a brick, 10 mm, that's less than a brick joint in a brick, relatively easy to achieve. But if we go to a roof under 10 degrees, we're 25,000 square mm per linear metre or 25 mm continuous gap. So we're talking three and a half times as much ventilation required for a flat pitch...

Jess Kismet (18:54)

Mm-hmm.

So this

is 10 degrees to cut off, so below 10 and above 10.

Clarence Macalister (19:19)

Yeah, and there's an intermediate between 10 and 15, but let's just talk 15 and above and 10 and below. it's, I'm not going to...

Jess Kismet (19:25)

15.

Yep. Yep. It's not super common to

have a 12 degree pitch roof, it? Not super common. Let's do it.

Clarence Macalister (19:35)

Well, look, well, I suppose

there's all sorts of weird stuff happening out there, but there are a lot of roofs under 10 degrees. There's a lot of roofs under 10 degrees. And...

Jess Kismet (19:40)

Yeah.

Yeah, a lot.

And

this is only in climates only 6, 7 and 8.

Clarence Macalister (19:51)

This is in climate zone six, seven and eight. However, however, And interestingly, climate zone eight is Alpine zone. And as far as I'm aware in Alpine zone, the roof pitch generally has to be above X degrees to allow for snow load to fall off the roof. in reality, and these are the interesting little nuances in the building code that you find out. Well, in climate zone eight, you more or less can't have a roof pitch under.

Jess Kismet (19:54)

It's like so, yeah, the south of the country. However.

Mm-hmm.

Clarence Macalister (20:19)

X degrees anyway, because the snow load. So, it's a bit of a moot point. But the interesting thing is, and there's no guarantee as far as I'm aware that National Construction Code 2025 is signed, sealed and delivered, but in National Construction Code 2025, as far as I'm aware, and I say as far as I'm aware, and I'm fairly certain, but not 100 % certain, that this will extend to climate zones four and five as well.

So more or less everything south of that, from the Queensland border south, the bottom half of the country, more or less, there's a few, but everything south of there will require those roof ventilation provisions. And there are some changes.

Jess Kismet (20:49)

Mm.

the bottom half of the country. Yeah.

except if you're in South Australia

because we've frozen our building code for a decade.

Clarence Macalister (21:15)

Yeah, well, and look, no, no, and look, it's interesting. And in the industry, I get to meet a lot of very, very interesting people. And Tasmania was a bit of a standout last year, last year, the last few years, because the president of Master Builders Australia is from Tasmania. The CEO from Master Builders was from Tasmania. The chairman of the Australian Institute of Architect was from Tasmania and the

Jess Kismet (21:17)

Just a little covey at this.

Clarence Macalister (21:45)

chairman of the Building Design Association of Australia, which is in Tasmania. And three of those four I know to say hello to and chat to. So I get to meet a lot of very, very interesting people. And anyway, one of them, Craig Edmunds who's the chairman of Master Builders Australia. We were having a conversation BAL this. And so what happened is the building ministers will sign off on whatever the draft provision is in the code. They'll say, we're going to sign off on...

Jess Kismet (21:52)

Yeah.

Clarence Macalister (22:11)

energy efficiency, waterproofing, bushfire, whatever the case may be. And what's been happening recently on several of these, the building ministers will collectively sign off because that's how the building code works. The building code has to have the agreement of the state ministers. And then before it comes out, they'll go, actually, we're gonna have a state variation on this. So we've signed up to have whatever these provisions are in the national construction code. But when it comes out, we're actually gonna...

have an exemption or a variation in our state. So what you say BAL South Australia is, I think it was described to me as either a checkerboard or a patchwork or something to that effect. ⁓ And I think this just reflects the complexity of construction regulation at the moment. It's phenomenal. And on that point, I was speaking to a lady just today and she sent me the set of plans. She wants some stuff done on her house. ⁓

Jess Kismet (22:54)

Yeah.

Clarence Macalister (23:10)

Nothing too unusual and the house was built in 1968. Have a guess how many pages of plans there were for a three bedroom brick veneer house built in 1968. One page of plans, one. One, if you had a, well it had three elevations it a floor plan, it had a footing plan, it had a section through and there was a lot on one page but.

Jess Kismet (23:21)

One.

wow, the floor plan, that's it. ⁓

You

Clarence Macalister (23:32)

But it was one page. interestingly, it was all rendered in with beautiful colors. And it was a thing of beauty. And a thing of beauty in that... No, it was a beautiful thing. And beautiful from a builder's point of view. think, gee I don't have to look at 27 pages to work out ⁓ what color grout I'm going to use in every individual room. But these days, a basic house...

Jess Kismet (23:38)

wow. wow. we should put that in a frame up on the wall.

Clarence Macalister (23:57)

I'd know what it is in South Australia. What is it in South Australia? A basic three bedroom, 170 square metre house. How many pages of plans would there be?

Jess Kismet (24:06)

20.

Clarence Macalister (24:07)

Yep, Tasmania 15 minimum, 15, 20. So, and I think that's just indicative of the complex. I think that's just a sort of an indicator of the complexity of construction. We've got 15 pages of plans, well, there's probably going to be significantly more confusion, regulation, rules compared to one page of plans. And I think it's going to be a fascinating time in the next, in the next...

10 to 15 years in Australia as far as energy cost, as far as building regulation, as far as building cost, as far as people's perception of the home's value, all these things, think there's going to be, there has to be a significant shift in our country as far as how we value these things because historically it's been who's got the biggest house and how many cars in the garage and from a cost point of view, but also an environmental

point of view, that's not particularly sustainable. And how that's going to shift and change in the next 15 years is, as anyone's guess, but it's all sort of up in the air to see how that lands. And the cost of construction, since pre-COVID, the last time I checked was something like 40 % increase in construction since prior to COVID and 60 % increase in construction in the last

Jess Kismet (25:08)

Yeah.

Hmm.

Clarence Macalister (25:35)

10 years. And then once we start putting in high performance buildings, we start putting in internal membranes, eight stars, heat recovery, under slab, edge slab insulation, thermally broken windows, etc etc etc Once we put that in there, that blower door testing, yep. And not only that, there are lots of other certifications that need to go in now as far as waterproofing inspections, etc etc That 60 % could very quickly become... ⁓

Jess Kismet (25:42)

Thank

Global testing.

Clarence Macalister (26:04)

more than 60%. And something's got to give. Something's got to give. ⁓

Jess Kismet (26:06)

Yeah.

Yeah. Yeah.

Yeah,

yes, yes, this is definitely a ⁓ topic that I hear a lot BAL a lot of in this space comes down to cost. And, you know, there's a long side, there's a long game here that we're playing, but you have to be able to afford the upfront cost in order to play the long game.

Clarence Macalister (26:22)

Yeah.

And part of that too is, and I was actually speaking to Dr. Dewsbury just this afternoon BAL, and the comment was something like people's ability to critically think. And look, we can have all these comments on society, etc are people watching grand designs on the Sunday night or are they watching Married at First Sight on Sunday night?

Jess Kismet (26:43)

Mm.

I know what I'm watching and it certainly isn't it certainly isn't MAFS

Clarence Macalister (27:01)

people can watch whatever they want. But anyway,

it's just an interesting insight into society and how it works and what people's priorities are. that's, who am I to judge what other people want? But how that pans out in the next 10 to 15 years, I think will be very, very interesting. And the whole renewables thing, sustainability, building health, it's fascinating stuff.

Jess Kismet (27:07)

Yeah. Yeah.

Yeah.

Okay, so summarizing roof ventilation, low pitch, ton of ventilation, there's a big gap you have to have in the low point and the high point of your roof. Higher pitch is much less easy to design for. Currently only in climate zones six, seven and eight, potentially moving up to climate zones four and five.

Clarence Macalister (27:34)

Yep.

Yes.

Jess Kismet (27:47)

If you're listening and you don't know what they are, look up the BCA climate zone map and you'll see it's all color coded. You'll see exactly where climate all the climate zones are. And you can sort of get your head around the areas of Australia that we are talking BAL right now. I'll link the map in the show notes as well. ⁓

Clarence Macalister (28:01)

Yeah, No, that's good. And look, suppose

another thing on that is that if you look back through history is that steep pitch roofs have been the overwhelmingly most common construction type since the dawn of time.

Jess Kismet (28:20)

⁓ It's interesting though,

I've just come back from Italy and I saw everywhere was flat roofs, everywhere. I was sitting in Positano in a beautiful breakfast balcony, a beautiful, beautiful place of the world. We're just sitting there having our coffee and our pastries on this beautiful morning and I'm looking out across the ⁓ view and I think I counted like five.

Clarence Macalister (28:24)

Yes.

Yeah right.

Positara, yes,

Jess Kismet (28:48)

pitched roofs out of a sea of dwellings on the side of this hill. And I thought to myself, does it not rain here? it not, I mean, the construction there is very different. It's all block work and concrete and the roof structures are, I don't actually know what they make their roofs out of, but I imagine they're very different to the types of roofs we build now here in Australia. But I just couldn't quite understand why all of their roofs

flat so I looked it up and it was actually to do with space so they use their roofs for growing vegetables and you know it's an additional living space so that was an interesting take on roof structure and reasons behind it.

Clarence Macalister (29:33)

Yeah, and I'm wondering whether that's a, it's a masonry roof as opposed to a timber framed roof and yeah.

Jess Kismet (29:39)

Yeah, I think so. There was actually

one that was being renovated as we were driving past one day. I actually saw, I took a quick picture of it and I'll put it up on the screen, ⁓ of a roof being renovated and it had this black membrane over the top of it, which I can only imagine was one of those like tar waterproofing type membranes. I couldn't see what was under it, but I would imagine it wasn't timber.

Clarence Macalister (30:02)

Yes, yes.

Yeah, and it would be interesting to know. And suppose there are all these regional variations depending on climate humidity, rainfall, etc etc I suppose, yeah, well, a Mediterranean climate, I don't know where Positano is, but in theory should be, Right, okay.

Jess Kismet (30:09)

I don't know.

Yeah, it's cold.

the Amalfi Coast, it was south, ⁓

middle of sort of middle of the country and but it was cold it was you know sort of like a you know 12 degrees during the day 15 down to four or five at night like it got cold at night.

Clarence Macalister (30:32)

Yep.

Yeah, okay.

Now, it would be interesting to know the local sort of dynamic of what's going on there. And look, I'm saying that in the most general sense BAL steep pitch roofs over history. And sure, there are the local variations and the vernacular interpretations of that. yeah.

Jess Kismet (30:45)

Mm.

Yeah.

I was just so surprised and it wasn't just there, it was

all through Rome and everything, like everywhere was just flat. I was like, this is, is, why?

Clarence Macalister (31:08)

Okay.

Well,

and look, suppose that's part of the whole thing is there are all these little, sometimes these differences are where you find out information that sort of pulls the whole story together or explains why that happens. Okay, interesting. Yep.

Jess Kismet (31:20)

Mm.

Yeah. Yeah. Yeah.

Yeah. But I think what you're saying, traditionally, particularly in Australia, flat roofs are definitely a new thing with the aesthetic, the parapets and not making the roof so you can't even see it and no shading. And that's a very popular design along Australian coastlines.

Clarence Macalister (31:32)

Hmm.

No,

that's right. And they're called parapet, flat roof, butterfly, whatever. And I was speaking to my son the other day and he came up with this very, very interesting term and he said, Dad, I think that's a bucket roof.

Jess Kismet (31:51)

Yeah.

Clarence Macalister (32:01)

a bucket roof because all the outsides are higher than the middle and, well, it's more than a bay, but I thought that was a very interesting way to describe a bucket roof. And when you think BAL it, are designed to shed water to the outside. And when we see essentially this reverse thing happening where everything's got high perimeters around it, well, it...

Jess Kismet (32:01)

⁓ Out of the mouths of babes.

Hahaha

Clarence Macalister (32:23)

It looks like a bucket, doesn't it? With a hole in the side. So look, yeah, the flat roofs are disproportionate ⁓ problems from all sorts of points of view. And even from the point of view, putting penetration, putting skylights, flashing them, etc etc Yeah, and it will be interesting to see how that pans out in the design space. so anyway, long and short of his, Mark and I have come up with some...

Jess Kismet (32:24)

a bit of a bucket. Yeah.

Hmm. Hmm.

Clarence Macalister (32:51)

after many sort of iterations, we've come up with some what we believe to be sensible solutions. But ⁓ the first point on that is it's not like we came up with those overnight. And secondly, they're all a considerable amount of mucking around to achieve them compared to business as usual. And I think one of the big challenges here, and this is historically what has happened. ⁓

Jess Kismet (33:11)

No.

Clarence Macalister (33:17)

for a number of reasons is a building designer or an architect will say, balustrade to NCC clause, waterproofing to Australian standard 3740. And they'll refer back to an Australian standard or a clause in the National Construction Code. Now, the thing here is if a building designer says build roof to NCC housing provisions 10.8.3, that and they haven't considered

ventilation, haven't considered insulation clearance, haven't considered all these things, that could be the difference between another 150 mm in roof height. And if we're talking in inner city development, like inner city Melbourne, Sydney, where your height limits are absolutely critical, that can make a big difference.

Jess Kismet (33:55)

Yeah.

Clarence Macalister (34:04)

So the other thing with...

the roof ventilation provision is there's a specific requirement for a roof space. so historically, ⁓ the depth of a roof assembly would have been dictated by the span of the rafter. So you might need an LVL that's 150 or 200 mm whatever the case may be to span, distance, whatever. And so what the situation is now is that there's a minimum roof space required and...

If you have insulation, so let's say we have R5 insulation with a nominal loft of say 210 mm something around there, then what that means is that your roof assembly must be the insulation height plus 20 mm as a minimum. So rather than just relying on what your structural requirements are, it's dictated to at least some degree by insulation. Historically, no one really cares what the insulation loft is, just squeeze it in there. But now, if...

Jess Kismet (35:03)

Mm.

Clarence Macalister (35:04)

insulation is lofting and closing that roof space, it is no longer compliant. And that's irrespective whether it's a ⁓ 30 degree pitch roof or a five degree pitch roof. So for the first time ever in a roof that the insulation is absolutely critical. And box gutters are one of those, especially box cutters on flat roofs, are one of those things that are more prone to people just squeezing stuff in there and poor ventilation. And a lot of funky designs that are really pushing the envelope.

Jess Kismet (35:07)

Hmm. Hmm.

Hmm.

Hmm.

Clarence Macalister (35:34)

Interestingly, we did a course in Canberra a few weeks ago and while I was updating some of the notes, ⁓ there was a thing I found on the internet, it just came up in my feed on the internet BAL a Frank Lloyd Wright house. Now anyone who knows anything BAL Frank Lloyd Wright, we know he's the most famous architect. Simon and Garfunkel actually did a song BAL Frank Lloyd Wright. How many architects had a song done BAL them? Anyway, there was a song BAL Frank Lloyd Wright by Simon and Garfunkel. And anyway,

This is one of his most famous houses was one called Falling Water, which was built over a waterfall. And this house just the other week had an $11 million repair bill on it. And that's not the first time it's been repaired. And in the blurb on this newsfeed was Frank Lloyd's rights aversion to flashings.

Well, surprise, surprise. So one of the most famous houses in the world, $11 million. And the guy didn't like flashings. And I recall something along the lines of Frank Lloyd Wright is known as saying, if the roof doesn't leak, you haven't been innovative enough in your design. So this is the bizarre, this is some of the weird stuff.

Jess Kismet (36:34)

Wow.

counterintuitive for a roof ⁓

Clarence Macalister (36:59)

and how many other architects as well known as Frank Lloyd Wright.

Jess Kismet (37:03)

I'm going to have to Google

that. if I find it or when I find it, I'll leave that in the show notes as well. Because that's bonkers. That was one of the most sort of the first ⁓ sort of projects that I sort of, you know, in my studies became aware of. So that's yeah, we're all taught BAL Frank Lloyd Wright.

Clarence Macalister (37:07)

Yeah.

Yes, as would a lot of other people.

But you didn't know BAL the Simon and Garfunkel song, did you?

Jess Kismet (37:23)

I did it. We'll also link the song because I'm not going to go and find it. Yeah, great. ⁓ So, yeah, you've been talking BAL... one more thing I want to ask you BAL roofs. OK, and this is just for my own, but also for the listener. So the 20 mm gap above insulation is written in. Ventilate, depending on pitch. If you have a vapour permeable membrane,

Clarence Macalister (37:26)

You can link this song.

Yes.

Jess Kismet (37:55)

Can you ventilate above that membrane instead of below it?

Clarence Macalister (38:02)

Yes, you can. You can. this is very interesting because in National Construction Code 2025, there's another big shift in that again. ⁓ So, if you're confused, don't worry because a lot of other people are confused. No. Yeah, yeah, yeah. And look, when I did the article, I...

Jess Kismet (38:19)

That's why I'm asking. I'm asking the experts so we can all know. ⁓

Clarence Macalister (38:29)

There's a lot of very smart people in the industry and I wanna make sure that if I'm doing an article, Mark and I doing an article that we're we're reflecting what is ⁓ representative of what the smart people in the industry or the relevant people.

feel or what their opinion is. And I sent this article out to many people and only one person picked up a very significant error, which ⁓ was Andy Russell from Procter. which is fascinating because all these other experts in the industry did not pick up a significant error in the article. Okay, so the error was

Jess Kismet (39:08)

And what was the error?

Clarence Macalister (39:11)

the error was, the error was. ⁓ It was interpretation of, it was basically an interpretation of sort of what you're talking BAL. And to be honest, I can't remember exactly what it was, but the long and the short of it is to say it's a significant, if people are confused, that's perfectly understandable. Now, again, coming back to this idea of trying to make things easy for people to understand, ⁓

Jess Kismet (39:35)

Yeah.

Clarence Macalister (39:41)

Mark and I, we did an article on LinkedIn a few months ago. We're doing another article for the Design Matters National online magazine, which should be available online shortly, which goes into some of these things to help demystify it because there's a huge amount of confusion around it. And I would be kidding you if I said, I looked at it the first time and go, I get this straight away. I didn't, not at all. And look, I think the other thing too that happens with

Jess Kismet (40:06)

Hmm.

Clarence Macalister (40:11)

with any of this. Let's talk BAL masonry and brickmineer. That's been around for 70, 80, however many years. Roof tiling, same. Wall framing, same. Footings, same. But things like even bushfire ratings that's been around 10, 15 years. So I've had a bit of time to get into it. Waterproofing, the same. But a lot of these provisions around condensation have only had a three to five year lead time. So unlike glazing provisions and snow loads and stairs and balustrades, etc etc that we've had

Jess Kismet (40:33)

Yeah.

Clarence Macalister (40:40)

decades or longer to consider that these are relatively new. And over time, people will get their head around them in the same way that people now go, I'll go BAL 29, I know I need blah, blah, blah, blah on BAL 29 because I had 10 years to get used to it. But when you start off with new regulations and also new regulations that are still a moving target, it's completely understandable that people don't get it.

Jess Kismet (40:48)

you

Mm-hmm.

Clarence Macalister (41:08)

In many ways, the building surveyors, the gatekeepers, and a lot of building surveyors don't get it, but who'd want to be a building surveyor? How many Australian standards does a building surveyor need to know? So ask the question. And who'd want to be a building surveyor? It's a tough gig. It's a tough gig. And we have this phenomenally regulated industry. And these people are supposed to be the ones who

Jess Kismet (41:16)

They don't get it either.

they need to know all of them and they just can't.

I know, hats off to them, honestly.

Clarence Macalister (41:37)

who are the catchall that understand everything and should be able to pick everyone up on it. It's a tough game. And I think in Tasmania, what, last time I was here, don't know, $4,000 ish Don't quote me on that for a new home. I mean you don't get much for $4,000 in any other part of the industry. this is what they're, look, it might be more, but the amount of money that they're expected, that they're charging to do this amount of work is,

Jess Kismet (42:05)

Mm.

Clarence Macalister (42:06)

Nowhere near enough in my opinion. And the risks associated with it are just huge. So the root ventilation is a complicated area. If people don't understand it, you're not alone. Mark and I are trying to get more resource out. But that being said, there's other companies out there that have good resources as well.

Jess Kismet (42:09)

Mm, mm, yeah, I agree with you.

Yeah.

So I will link

your LinkedIn article in the show notes as well. And when your new article comes out, that may or may not be out. It should be out by the time this episode is released. I'll link that one too, because I remember reading your LinkedIn article and getting a lot from it. So I think that the listener will too. Yeah, yeah.

Clarence Macalister (42:39)

Yes.

That's good. That's good. And ⁓

I ⁓ think everyone can get something from it, whether you're fairly new to the industry or fairly experienced. ⁓ I think that there's such a wealth of knowledge if we work with each other, we can all sort of lift and lift each other and that's great.

Jess Kismet (43:06)

Yeah, totally. can

you quickly, so you can ventilate above and not below. Does that depend on the pitch of the roof? Like if you've got a roof void, if you've got a 20 degree pitch and you've got a vapour permeable membrane and you've got your vented cavity above the membrane, got your 20 mm you've got all your stuff, do you still have to vent under the membrane as well? ⁓

Clarence Macalister (43:23)

Yes.

Yeah, and

now you do not need to vent under the membrane. Now, the...

Jess Kismet (43:34)

But that's gotta be a class

four vapour permeable membrane, right? It can't be anything less.

Clarence Macalister (43:40)

are as far as I'm aware. As far as I'm aware, it's a class four vapour permeable membrane, as as I'm aware. Now, the other thing with this too is, and this is something we do a lot in the training, is this thing between mass transfer and diffusion. So water vapour going through a membrane is diffusion. Humid air being transported out.

Jess Kismet (43:41)

I think there was a cutoff.

Yeah, yeah, okay.

Clarence Macalister (44:08)

by air movement is mass transfer. So mass transfer is hundreds or thousands of times more effective than diffusion. if at all possible, if at all possible, you want to, and I'll put a caveat on that. If at all possible and the design allows for it and the energy efficiency allows for it and the system, the system allows for it, as far as

Jess Kismet (44:15)

Yeah.

Yeah, both.

here.

in terms of the building system.

Clarence Macalister (44:37)

Passive house does not allow you to ventilate under the membrane. But if the system allows for all things being equal, considering all the factors, ventilating is going to be more effective than diffusion. ⁓ Correct, as far as getting rid of moisture is concerned, correct. And there's sort of nuances in the British standard as far as the long and the short of it is, if you have a

Jess Kismet (44:42)

No.

at getting rid of moisture.

Clarence Macalister (45:07)

a vapour permeable membrane, the amount of ventilation under the membrane is less. You've still got to ventilate, but it's less. But look, there are all these nuances. so yes, you can have a vapour permeable membrane and have your roof space above that vapour permeable membrane. And look, I think part of what's happened here with NCC 2022 and more so with NCC 2025,

there are people at the pointy end of the industry with Passivhaus for example, saying, we want to do blah and blah and blah. We do not want to have to ventilate under our membrane because that completely upends the Passivhaus system. the code has to allow for these other forms of construction that are the sort of generic forms of construction.

Jess Kismet (45:53)

Mm.

Yeah, and I think this actually

goes back to what the Joe Lstiburek comment BAL, don't ventilate your fricked roof. I think what he is talking about is not the standard Australian roof with a roof void He's talking about a more high-performance type roof.

Clarence Macalister (46:17)

Yeah, and this is where all these nuances and details come in. And a thing we're very big on in training is whatever you do, don't say, ⁓ this is what they do in America or Canada or Europe, without making sure you have the whole system. Because you can take, that's right, and you can take part of a system.

Jess Kismet (46:22)

Yeah.

Hmm.

Yeah, there's a context that goes with.

Clarence Macalister (46:42)

and apply part of the system without understanding. And a very significant one is, okay, in the US, they're over-sheeting all their buildings. So what they're doing, well, not all their buildings, but it's very common to have an OSB-oriented strand board that looks more or less like plywood over the top of everything, and then put a membrane on the top, and then put their shingles. This is what they do in America. But is the OSB or plywood or the material they're using in America, the same as the one we go and get from the local hardware shop? And I call it...

Jess Kismet (47:02)

Mm. Mm. Yeah.

I don't

think it is. I got told it's not the same. It's got different glues and stuff. Yeah.

Clarence Macalister (47:13)

Well, well, it's completely and I call it the orangutan

hardwood, it's probably straight out of the Malaysian rainforest with a few bits of orangutan fur and ⁓ yeah, you've got to be politically incorrect. ⁓ But the reality is, it's all very well to think we're doing the same thing, but it only takes one small thing to be different and the whole system can fall down and we're

Jess Kismet (47:22)

you

You

Mm.

Clarence Macalister (47:38)

I was mentioning to you before, was some, and I can't say too much about it, because it was a catastrophic failure where someone thought, I will do this and use a local product. The product didn't suit the building, so they started asking a few questions. The client started asking a few questions and $600,000 worth of building was demolished and the builder went bankrupt. And this was a thing that had they asked the right question at the right time, that could have all been avoided. And, ⁓ this seems okay.

but it wasn't okay and $600,000 later, the builders bust, the place has been demolished and for a few simple questions, this could have been avoided. ⁓ look, it's no different to saying, I've got a Toyota such and such I'm going to put a Nissan fan belt on it. Well, it might look the same, but when it all blows up, who's gonna warrant the car? And it's the same thing, whether it's waterproofing membranes, whether it's... ⁓

Jess Kismet (48:17)

Yeah. ⁓

Clarence Macalister (48:35)

any other complex system, have to make sure we're following that system.

Jess Kismet (48:40)

Yeah,

think that's right. think that getting some context around Joe's comment is important. Because if you just apply that don't vent your freaking roof to your standard Australian roof, ⁓ you could end up with some problems. And the reason behind what he said was to stop roofs blowing off during cyclones and to stop

fires from starting in roof spaces and it's the right advice but it needs a broader context around it to make sure that it's a healthy roof

Clarence Macalister (49:18)

That's right. And every area has its own sort of differences that need to be factored in and whether that's a masonry based roof in Italy that happens to have the correct waterproofing compound on it or whether that happens to be a Passivhaus roof assembly that you do not want to ventilate under the membrane.

Jess Kismet (49:33)

Hmm.

Yeah.

Clarence Macalister (49:40)

one difference can make a big difference. And there was a very interesting study many years ago, and it was in the Pacific Northwest of Canada, and a journal article, a scientific journal article, and the long and the short of it is that it said that the simplest way to minimise condensation in a roof is to...

Jess Kismet (49:42)

Yeah.

Clarence Macalister (50:00)

have more heat flow into the roof and have more heat flow into the roof means take out the insulation because what was happening is that they were finding that the external humidity in the natural environment was so high and the roofs were naturally so cold because of the amount of insulation in the roof that it was very, very hard to stop high humidity in the roof because there was high humidity outside and cold roof.

So Villy Yordanov from Pro Clima had some interesting posts on LinkedIn last summer, I believe, or maybe the summer before BAL Sydney, and

when it was El Niñera or La Niñera, whichever one is, creates the high humidity in Sydney, that even if we ventilate buildings as well as we possibly can in Sydney in the middle of summer, when you've got a dew point of, whatever, 18, 19 degrees, that it is virtually impossible to have healthy humidity inside a building unless you are specifically having dehumidification in the building.

Jess Kismet (50:50)

you

Clarence Macalister (50:59)

And again, as we move to more high performance buildings, as we move to more moisture sensitive materials, that problem becomes worse and worse. So historically, when we had durable materials, sawn timbers, hardwoods, didn't have paper-faced plasterboard, didn't have MDF skirtings, etc that might not have been so much of problem.

Jess Kismet (51:00)

Yeah.

Clarence Macalister (51:25)

but as we're moving towards these more moisture sensitive materials, etc, those are variations in humidity can make a significant difference. And how that then marries in with human health is another question altogether.

Jess Kismet (51:36)

Yeah.

Yeah. Could you go back and give us some examples of some of the disaster sort of, well, the experiments gone wrong that you've seen? you were chatting earlier and you were telling me about a couple and there was one about a roof. And so I'm keen to flesh that out a bit.

Clarence Macalister (51:41)

Hmm.

Yes, yes, yes, yes.

Yeah, so look, that one was a 1930s traditional hardwood frame, steep pitched roof, big gable end with weatherboards on them. And that had been wrapped up tight as a drum with blue and silver sarking, then had the full length.

Colourbond sheets put over the top, which is standard practice. And people say, what's the difference between a full length color bond sheet? Well, what happened with the old sheets, they were typically 8 ft or 2.4 meters long, they'd span over a few battens. And so they naturally had lots and lots of little gaps everywhere. And when we're talking about a steep pitch roof and it's saying you need an equivalent of a seven mm gap, continuous gap, if you've got 2.4 m sheets everywhere, lap, lap, lap, lapping over each other,

you're naturally going to get these 7mm gaps everywhere, but as soon as you put full length...

lengths of colour bond that are six metres long with perfect lapse on them, that 7 mm gap is soon non-existent. So just by changing that, the method where we're wrapping them up, that ventilation disappears. Anyway, this roof, I've got some sensors in that roof and it is in winter, three or four days of the week in winter, it will be into 100 % humidity. And the 100 % humidity is typically from 9 till 12 in the morning, which is interesting. It's not actually at...

five, six, seven o'clock in the morning, which is the coldest part of the day. It's actually a few hours after the coldest part of the day. And the humidity and the moisture in those battens is 35 % moisture content in those battens. And I'm actually working on that house at the moment, getting some ventilation in there.

Jess Kismet (53:28)

Mmm.

Clarence Macalister (53:42)

So here's an example of we can have an apparently is the word innocuous or innocent or well intentioned upgrade, which

is extremely common throughout Australia. And here's a building that's been functioning perfectly fine for the last 90 odd years. And all of a sudden, we create a situation where we're getting extremely unhealthy conditions in that roof space because of one simple action. The flip side of that too, is that if that had been a radiated pine frame instead of a hardwood frame, it would be absolutely caked in mould within a few years. But again, this is part of the beauty of

what I get to see is these experiments. Now we get to say, okay, we're gonna flip the experiment and see how we can rectify that and what factors we need to incorporate in to rectify. And that's a really interesting thing. ⁓

Another one, and it's interesting, it's a bit like, I don't want to say the wrong thing, but a bit like the odd couple, Mark's the mad sort of, or the eccentric academic, and I'm the scruffy builder. And between us, we find out all sorts of interesting stuff. And there are several of these things. I found these things in houses, Mark's came out, and then at the next scientific conference, Mark has said, this is what we found in houses in Launceston.

Jess Kismet (54:49)

You

Clarence Macalister (55:03)

This other one is absolutely fascinating. And we've seen multiple times where passive solar design would say you have your bathrooms and your wet areas and your laundries on the south side of the building. It makes sense. Okay. What's happening on the south side of the building? Getting less direct ventilation, higher thermal mass, poor airflow. They're not opening the windows, naturally colder.

Jess Kismet (55:18)

don't know what you're gonna say. It's cold.

I'm

My goodness,

of course.

Clarence Macalister (55:29)

And we've seen these buildings where all the joists on the north side of the building are as good as the day they went in. But on the last two meters underneath the bathrooms, wet areas, kitchen on the south side, you can pull them apart with your hands. And this is good passive solar design or energy efficient design, whatever you want to call it. But the hygrothermal

Jess Kismet (55:40)

Yep. Yep.

Clarence Macalister (55:51)

Flow on effect can be catastrophic. And we've seen houses less than 20 years old where half the joists, most of the joists on the southern side are just like styrene foam, can be pulled apart with your hands. And these were built to code 17 years and it's not uncommon.

Jess Kismet (56:05)

Wow. Yeah, of course.

And that's not even that long ago, 17 years ago it was 2007, that's how old my daughter is, like it's not even that long ago.

Clarence Macalister (56:18)

Yeah, built this century and built to code. And by that time, the building codes had, they were robust, were representative of how we should build good houses. Not like this is 1950s technology, but again, a lot of these floor systems are either radiata pine or engineered timber. Had they been ⁓ a a sawn hardwood,

that 20 years could very easily be 50 years to a failure, whereas now it's 20 years. And again, we think, we're using timber under the floor, ⁓ but not all timber is the same. And these are the things that only takes a few little changes that might appear insignificant and they all add up. That's exactly right. And the durability and the drying and that's...

Jess Kismet (56:56)

I'm sorry.

It changes the heat, air and moisture where it all goes.

Hmm.

Clarence Macalister (57:12)

Another thing Joe Lstiburek was saying in the podcast a few weeks ago, and you must have some, what's the word, negotiating power to get Joe to come to your things, Jess. Good for you. Yeah, no, good luck to you. That's great. And ⁓ the ability to dry paired up with the durability is a really important factor.

Jess Kismet (57:24)

I was pretty happy with myself with that one.

Clarence Macalister (57:37)

And look, and we're seeing all these weird and wonderful things all the time. And one just a few weeks ago, a 13 year old build where all the cladding had to come off, the flashings hadn't been put in correctly, that had not been installed correctly. ⁓ 13 years old and all the cladding's completely rotted. There's rot around all the... ⁓

Jess Kismet (57:37)

Yeah.

Clarence Macalister (58:01)

the timber framing and a whole lot of remedial work had to be done just because the flashings weren't done correctly. so whether it's a modern house or a 60 year old, 100 year old house, we're seeing these things all the time. It's really interesting. And then to be able to tie that in with Mark's research that he's doing with people like Hartwig-Kunzel from Fraunhofer, it's a fascinating mix to be able to pull the practical every day to the scientific research and blend it all in. It's good stuff.

Jess Kismet (58:13)

Yeah.

think that's what you and Mark did beautifully. It's a beautiful pairing, beautiful relationship you've got going.

Clarence Macalister (58:36)

Or maybe the odd couple, which is... ⁓

Jess Kismet (58:40)

I have

a couple of questions that I don't want to let leave my mind. So what is it about the sensors that you've been installing in roof spaces? And the other one has left my mind. No, the other one is.

Clarence Macalister (58:46)

Yes.

Jess Kismet (58:53)

Let's just go with the roof sensors, the other one might come back to me.

Clarence Macalister (58:55)

Yes, yes.

So, so look, now I've done the WUFI training, I think you and I first did our first WUFI training several years ago at the same time. anyway, for one reason or another, well, I haven't followed specifically down that WUFI path. But the thing is, when we do a hydrothermal modelling, there's a lot of questions which are a lot of parameters which you cannot answer 100%. So let's say we have a design and we say, okay, we're

90 % sure it's gonna be in this range and whatever, whatever, with all these parameters, we can never be 100 % sure. And we do, it's fascinating. We do this training and builders will come to me, they never come to me or Mark with the easy questions. They always come to us with these outrageously complicated questions. Oh man, oh man. mean, you're asking me the like 0.1 % question, not the 10 % question. We can answer the 10 % question. Anyway.

And so what we've come up with, which I think is really fascinating is, or a simple solution is, and there are several builders doing this, Sean Buchanan's doing it, there are several other builders I know who are doing it, and they say, we've got to... And I'll tell you a story BAL Sean. I'll tell you a story about Sean in a minute. But anyway, it's a great story. But what's happening is we're putting these, we say, if you're not sure,

Jess Kismet (1:00:02)

He's actually a guest coming up by the way, Sean Buchanan. I've got him lined up. He's amazing.

You

Clarence Macalister (1:00:18)

put some of these sensors in the roof. They cost $200 $300 each. They'll send out a signal every 15 minutes to your phone or your computer. You can monitor them remotely. They have a several year battery life. so from what's happening is we say, we're not sure how this is gonna work. We're fairly certain it's gonna work. We're not absolutely 100 % sure. So put a few of those sensors in your roof, monitor them for the first couple of years, see what happens if...

Jess Kismet (1:00:43)

and its relative humidity and temperature.

Clarence Macalister (1:00:45)

Correct. And you can

Jess Kismet (1:00:46)

Yep.

Clarence Macalister (1:00:47)

get sense that we'll do all sorts of weird and wonderful things, but relative humidity and temperature. this is, they're the two camps. And this is what hydrothermal is, this is what WUFI is, laksdlk;dj temperature and humidity, temperature and humidity, temperature and, and that's what WUFI does, temperature, moisture, temperature. Everything's about those two. And from that, everything else flows. And so put those in your roof. And if you're going through your first winter and you're never getting a...

Jess Kismet (1:00:49)

Yep, they're the two key ones.

Whatever it is. Yes.

Mm-hmm.

Clarence Macalister (1:01:14)

above the mid 70s of humidity or it might just be creeping in there for a short period, happy days. And so what that does, it gives you peace of mind, it gives your client that quality control and you know how your building's working. If you go through the first winter and you're getting 85, 90 % humidity regularly in your roof, say, okay, we know there's a problem, we can go back and address that in the first year. Rather than there being a problem five or six or 12 years down the track, you say, okay,

Jess Kismet (1:01:24)

Bye.

Mm-hmm.

It sense.

Clarence Macalister (1:01:43)

We know there's a problem, we can address that problem. We can actually leave the sensor in the roof and check that that is actually, that that humidity has been dealt with by our remedial action. And look, $200 $300 a sensor, you get an electrician to put a PowerPoint in it's $300 bucks. And it was only five or eight years ago, if you had to do that, you had to go there, take off roof sheets.

Jess Kismet (1:02:03)

Yeah.

Clarence Macalister (1:02:10)

put in a moisture meter, put the roof sheets back on, get a harness, get a ladder, blah, blah, blah, and go to it multiple times in the winter. Whereas now it can all be done on your phone remotely. And as far as knowing how your building works, quality control, assurance for the client, knowledge of what you're doing, it's amazing. And there's one I'm working on at the moment. It's a church with a whole lot of, I do a lot of...

work on religious buildings one way or another and not just churches have done so on mosque and mosque as well. Anyway, so they've got this problem with subfloor ventilation and they've said to me, the engineer said the subfloor ventilation is fine. I said, you are not getting below 80 % humidity ever in summer in your subfloor under that church. You, there is.

Jess Kismet (1:02:59)

Mm.

Clarence Macalister (1:03:05)

absolutely not enough subfloor ventilation. The engineer said there is a well, is the engineer a hygrothermal specialist? And again, you can have these arguments till the cows come home, or you can say, here we have the data, we know that in summer, the humidity under the floor is never getting below 80%, the problem has not been solved. Do we need to spend more money? Yes. Why do we need to spend more money? Because this is the information we're getting. And that's

Jess Kismet (1:03:05)

a problem.

Has it? Yeah.

Yeah.

Clarence Macalister (1:03:33)

the cost benefit on that is just phenomenal. And I've got these, I've got 10 of them in floors and roofs and walls all around Launceston. I've even got some in my own house with, as a point of referencing, because we can have all these hygrothermal models, but do I know what the typical moisture profile in the humidity profile in a pitched roof in Launceston or in Adelaide or in Sydney is?

Jess Kismet (1:03:37)

Absolutely.

Clarence Macalister (1:04:01)

We don't have that data. So even having that as a benchmark that we can say, okay, well, I know that in my old roof, is ventilated like nothing else, that I can see what the typical humidity profile is in that over a season and compare that to other buildings, is it above or below? And we've got a benchmark. And for a few hundred dollars a year, it's nothing. ⁓

Jess Kismet (1:04:24)

It's a my brainer.

And I think the performance of the roof, mean, people like you and I and, you know, builders and anyone who's entrenched in this stuff every day knows how important the roof is to performance.

Clarence Macalister (1:04:34)

entrenched,

entrenched in this stuff, immersed or entrenched. So, now anyway, it's all good. Yeah, yeah.

Jess Kismet (1:04:37)

Yeah. Don't they mean the same thing? I

don't know. Now I'm to have to go and look it up to make sure I'm saying the right thing. you know what I mean. So we're all in this. We're up to the eyeballs in this stuff every day. And we understand that the roof matters. But I think for your general person just living in a house, don't think BAL roof performance. So it's up to us to, you know, like.

Clarence Macalister (1:04:46)

Nah, I'm just, yeah, nah, so good. Yes, yes. Yes, yes.

Jess Kismet (1:05:04)

The roof is facing the sky. It's where all the sun goes, all the water goes. It's up there. It's protecting us from all of the elements. monitoring the performance of that roof is actually something that is fairly important, but we don't do it.

Clarence Macalister (1:05:20)

and look, think whether it's the roof and another one of my pet things is subfloor ventilation, because the number of problems I've seen in buildings just because of either poor subfloor ventilation and or poor drainage under the subfloor is phenomenal.

And in Tasmania, there are a lot of old buildings with bearer and joist suspended subfloors. And I believe we've got still got a lot of them compared to the mainland.

I've seen multiple situations where poor subfloor ventilation and poor or high levels of moisture in the subfloor has been the cause of condensation or mould or moisture problems in other parts of the building, including the roof.

Jess Kismet (1:06:07)

Is that because the moisture travels up through the walls, like in a brick veneer house?

Clarence Macalister (1:06:10)

⁓

well, all of the, it can travel through multiple paths, including through the walls, including if you've got an old house, correct, through all the gaps. And obviously with the yellow tongue floor, is technically a vapour barrier, it's going to go more around the wall path and through the, through through the, ⁓ through, through a tongue groove type floor. But there was a house I looked at in

Jess Kismet (1:06:16)

or just through the conditions space. Wow.

Clarence Macalister (1:06:34)

in Southern Tasmania, can't say too much about it. was all a big legal stoush legal problem. And everything had been built to code and the people were, to, they were sleeping in the lounge room for two years because the bedrooms were uninhabitable. The amount of mould in the roof was just off the dial. And it would appear that the...

Jess Kismet (1:06:57)

and

Clarence Macalister (1:07:01)

main contributing factor that was poor subfloor ventilation. so this is the thing that we can have and it sounds completely counterintuitive but we've seen it multiple times is where a problem, we've seen a few times where a problem in the roof actually is originates through poor subfloor ventilation.

Jess Kismet (1:07:05)

Wow.

Clarence Macalister (1:07:21)

look, this is the sort of thing Mark and I come up with all the time, all this weird and wonderful stuff. So what I've got now, I've got a hand auger, which is this beautiful thing. So when you get into this sort of stuff, you get excited about things like hand augers. It's made by an Australian company called Dorma. They're not cheap, they're a thing of great beauty. Anyway, we auger these holes down, 65mm auger, put a 50mm PVC pipe in that hole with a whole lot of drill holes in that pipe.

put a plastic cap on that and then you can actually see how deep the water table is under the ground. So you can actually basically look into the ground, see what's happening with the water table. And we've done this several times where people say, where do we need an ag drain? How deep does the ag drain need to be? Have we got a moisture problem? Well, we put these holes in the ground everywhere. You go and stick a broom stick down in the middle of winter, go and stick a broom stick down in the middle of summer, see where your water table is, see what your problem is. So instead of having to guess,

Jess Kismet (1:08:16)

You're welcome.

Clarence Macalister (1:08:18)

what the problem is. You can see it's like x-ray vision into the soil. And these are the weird and wonderful things that we come up with. But the practicality of the solution is just, it's amazing. And simple, beautiful and simple. And Tim Law and I worked another semi-destructive way up to look at deterioration of timber floor framing with a torque wrench and some screws, which was a brilliant way to work it out.

Jess Kismet (1:08:28)

It's so simple.

Clarence Macalister (1:08:45)

And we're developing this stuff all the time. Coming back, this is a nice segue into the thing about Sean Buchanan is that Sean attended some of this training that Mark and I did. He was one of the first people when he was working for Zanetto Homes. And I can actually remember, they were sort of up the back yibby abbering, were like, just shut up. And I think what it was that they were just so interested in that they were having this conversation because they were so interested and thought, shut up. But anyway, long and the short of it is.

Jess Kismet (1:09:12)

Hahaha!

Clarence Macalister (1:09:14)

Here, and Sean's a great bloke, but here it is three or four years later, and the conversations I have with Sean about air tightness, about blower door testing, about humidity, about vapour control, about air leakage around windows, about window seals, about the vapour resistance of yellow tongue flora, blah, blah, blah, blah, blah, is, this is not someone who's just gone and listened to me and repeated what I've said. It is someone who's gone many levels above,

with his own ⁓ motivation to find this stuff out. And this is what I find fascinating about because I've been to university, I've got an honours degree. I know a lot of people with PhDs who are very, very smart people, but there are a lot of builders out there who have never been anywhere near a university, but the level of knowledge and skill and aptitude and problem solving and intelligence and practicality and...

ability to put that all together, it makes my head spin. And someone like Sean, I look at what he's doing and here he was, he's absolute and there are several of them. And I say that these guys, they're just smashing it. And the level of knowledge they're bringing to the industry and bring to their clients and sharing that knowledge is on par with anybody who's got a PhD. I don't care what topic, is amazing.

Jess Kismet (1:10:12)

⁓ He's next level.

Clarence Macalister (1:10:37)

I think this whole thing with historically in the building industry, I build architectural houses, that's nice. I mean, that's wonderful. But now people can say, I'm doing something special in the building industry, but there's actually some measurable performance or measurable knowledge that goes with that rather than just having a big fancy ute with your name on the side saying you do architectural homes. There's a real metric to say, this is what I'm doing. You can put...

information, measurable performance with your building that actually says, I don't just think I'm building better, I know I'm building better and this is why I'm building better and here's all the information that goes with it. And this isn't just because I'm beating the chest with the big fancy truck with my name on the side, it's a provable, measurable thing. And to see how that's evolved and look, Mark Dewsbury in many ways started this, he's been doing this for 15 years, he started the snowball.

Jess Kismet (1:11:16)

He's the first.

Hmm.

Clarence Macalister (1:11:33)

15 years ago, I happened to get in the snowball sort of five, seven, 10 years ago and I got caught up. then other people like Sean and Kyle's Zanetto, and  Luke Davies and Tim Law have got caught up in the snowball and the snowball is just getting bigger. And it's a pretty exciting snowball to be part of. Hmm.

Jess Kismet (1:11:49)

Yeah, absolutely. This is

a, I keep sort of saying none of this stuff is taught in architecture school. Although having said that, I have had some South Australian universities reach out several times just this year. So they're upping their game as we speak. We're doing presentations and interviews and all that sort of thing right now, which is so good to see. Because up until now, I haven't heard one architect say they learned anything abour any of this at their, during their studies.

Clarence Macalister (1:12:08)

Yeah. Yeah. Yeah.

Jess Kismet (1:12:18)

Same with carpentry apprentices or any of the trades. They don't learn about any of this stuff in trade school. So it's all a self-driven, self-motivated journey to understand all of this stuff. And guys like all those people that you mentioned, plus many more, the builder I work for, Jackson Digney from Enduro, it's all self-taught, self-funded, self everything. And so to a builder,

is not the same, this builder is not the same as that builder, this architect is not the same as that architect. So when you go to engage a builder or you go to engage an architect, it's really, really well worth doing some homework on their background and their understanding of building science principles, because you'll get a very different outcome. Would you agree?

Clarence Macalister (1:13:00)

⁓

no, absolutely. That's absolutely right. And look, the dumbing, I shouldn't say dumbing down, but I suppose you'd call it the streamlining or rationalisation of the industry at all levels in the last 15, 20 years is significant. And look, I see this whole...

Jess Kismet (1:13:03)

Mm.

Clarence Macalister (1:13:22)

building, I'll call it building performance, building science, building technology, whatever you want to call it, it's been a way for a lot of people to of re-engage with the profession and skill of the trade rather than we're just putting bits of nails into wood. But the fascinating thing that's happened in Tasmania, and I don't know whether it's just a Tasmanian thing, but... ⁓

And we had Zara D'Cotta down here 12, 18 months ago. And she said the thing that blew her away most about Tasmania is that all these people that I've mentioned and what I'm not trying to do, I'm not trying to name drop here. It's not about name dropping. It's about giving credit to people who've been the front runners, who've been pushing the envelope. It's to give credit to those people where it's due because there are a lot of us who've been involved in it. But the thing is,

nine times out of 10, people will say, here's what I've done. Here's how I've solved the problem. Hey, let's sort of compare notes to see how we can do this better rather than this is my turf, rack off, I'm not going to help you. And apparently in other jurisdictions, the rack off, it's my turf mentality is dominant, whereas in Tasmania, it seems to be quite the opposite. And the other side of that for me, and I actually...

Jess Kismet (1:14:38)

Yeah.

Clarence Macalister (1:14:44)

bumped into them today, Nathan and Lockie from Modern Homes in Launceston and the stuff they're doing is phenomenal as well. And I can have a conversation with them. They'll invite me onto their jobs, show me what they're doing, show me how they're solving a problem. We have that conversation and people just share that information. And it's absolutely amazing. And to see everybody just want to work with each other and improve that is, it's pretty special stuff.

Jess Kismet (1:15:11)

Yeah, I think that's quite common in just this better performance, better buildings industry. Like it's the same here in South Australia. know, the builder I work for, Jackson, will willingly go on to anyone else's building site and share what he knows to help them bring the performance of their home up. In Victoria, it's the same. There's a lot of information sharing there between the builders in this game. I think, you know, it's really

great to see everyone working together just to because we've all got a similar mission. That's another thing that I really love about our ⁓ part of the world.

Clarence Macalister (1:15:47)

No, I...

Yeah, and look at coming back, sort of going back a few steps and then sideways a little bit is there was a webinar and it was one that Tim Law was on. For people who don't know Tim Law, get online, look at some of his stuff because he's an incredibly sharp, one of the sharpest minds I've ever met. And it was, he was on a panel and it was a health-ish, a health...

focused panel rather than building focus panel. And these research in the public health area were saying that one of the best ways we can improve public health outcomes is building better buildings. And we're talking the tunes of tens of billions of dollars.

Jess Kismet (1:16:34)

Absolutely.

The potential is endless. And not just physical health, mental health. That family we talked about

with the $600,000 building that they had to demolish, not just the mental health strain on the builder and on the family. When you told me about that, I just couldn't like that. That was what immediately came to mind. It's not just physical health because of moisture issues. It's the mental health strain.

Clarence Macalister (1:16:48)

Yeah.

no, totally. And, and

now that that's right. And when you see people, you see people with three children all sleeping on the couch in the living room, because they can't sleep in their bedrooms. That's marriage, that's marriage breaker stuff at, at, yeah, or worse. And, and, and look, whether it's whether it's

Jess Kismet (1:17:12)

Mm-hmm. I've seen it. Absolutely. Absolutely. Absolutely.

Clarence Macalister (1:17:23)

the mold and condensation or failing bathrooms or yeah, I've been in those situations before. People have bought a new house and five years later they can't use any of their bathrooms. It's, and look, it's the interesting thing is mould condensation, waterproofing, water ingress, etc. They're all just sort of different sort of facets of the same fundamental problem. Yeah. Yeah. ⁓

Jess Kismet (1:17:48)

Yeah. Yeah.

Clarence Macalister (1:17:52)

Another interesting thing is this whole thing about the decks over habitable rooms. Now, coming back to this roof ventilation is that we've got, there's three exemptions for the roof ventilation, structural insulated panels, concrete roofs and roofs in a BAL FZ zone. Now, the BAL FZ zone, that's in the two hard basket, but that's a whole other thing.

Jess Kismet (1:18:16)

That's a whole nother kettle of fish.

Clarence Macalister (1:18:18)

That's a disaster. But the other thing that looks like a roof and walks like a roof and quacks like a roof and flies like a roof is a tile deck over a habitable room. It's doing everything a roof is doing, but there is no requirement for ventilation under a deck over a habitable room, even though it's doing everything. If you had corrugated iron on top of that, instead of tiles, you would have to have structured ventilation. But as soon as you put tiles on that,

over habitable room, you don't need to ventilate it. So why is that not a roof? And what are the hygrothermal problems around tile decks over habitable rooms? My recollection is Jesse Clark online once said, if I had to design something for condensation and mould failure, this is the best thing I could possibly design.

And there's nothing stopping people doing them. However, more and more designers are saying, we're just not doing them. Or we've got to find some alternative solution because they're significantly problematic.

Jess Kismet (1:19:09)

There you go.

there you go. I just learned something. It's not something I'd ever thought of or anyone has ever asked me about

Clarence Macalister (1:19:28)

Hmm. Yep. And it's doing everything a roof is doing. If that had tin over it, it would have to have structured ventilation. Put tiles over it. we don't need to ventilate it. But it's doing everything a roof will be doing. Hmm.

Jess Kismet (1:19:30)

Well.

⁓ yeah.

I guess the people, you know, it just comes back to the people writing the building code are just people. You know, there's no overlord that says that they're going to get everything right. And we all know that there's, there are things that need to be done over and above the building code to make it healthy. And that's just another example to make any structure healthy. And that's just one more very good example.

Clarence Macalister (1:19:48)

Yeah.

Yeah, what I'll do, I'm just at my desk, just bear with me. I'm a bit old school and I've got a copy of the National Construction Code when it was printed, still printed, from 2016. And in the front of the building code, it says that... The long and the short of it is...

Jess Kismet (1:20:10)

Mm-hmm.

Clarence Macalister (1:20:36)

The Commonwealth Government does not accept any liability whatsoever regarding damage, injury, blah, blah, blah, from using what's in this publication. Okay. And this is the 2016 National Construction Code. is this is the, it's, it's, it's, it's, it's, it's, it's, it's, it's, it's, it's, it's, it's,

Jess Kismet (1:20:53)

This is your typical legal disclaimer. This is the rules, but we don't want to hear about it.

Clarence Macalister (1:21:03)

This is page no.3. No liability for using or relying upon any information in this publication to the maximum extent permitted by law. That's on page two of the National Construction Code. so what that means, and I apologise for the disruption of getting the book down off the shelf, but what it means is that you can follow every single thing in the National Construction Code, and if your house falls down and everybody in it

is, you know, ends in tears, that there is nothing, no comeback you have on the government at all. Okay, but this is the interesting thing. is, 20, 30, 50 years ago, we had a brick veneer house look like this, a truss roof look like this, ⁓ double brick look like this, ⁓ lightweight clad with weather boards look like this.

Jess Kismet (1:21:35)

parishes.

Clarence Macalister (1:21:58)

But in the last 20 years, explosion of materials with double glazed thermally broken windows, tiles over habitable rooms, swimming pools and foam cladding and on and on and on. So there's no longer these sort of four vernacular ⁓ methodologies of construction. There's an infinite number.

Jess Kismet (1:22:09)

Mm.

Clarence Macalister (1:22:18)

So we have this plethora of construction types, methodologies, materials, assemblies that the National Construction Code simply cannot cover. There's just no way it can cover the multitude of permutations, combinations, assemblies, etc. And so more than ever, we have to say it is the bare minimum. And as we're getting more more funky designs and different materials, and if you went back

to the 1970s and told builders then we're gonna be putting styrene foam on the outside of our buildings, they would have laughed at you. If you said we're gonna be using MDF skirting, they would have laughed at you. ⁓ But that has just become accepted now. ⁓ If you said we're gonna be building bucket roofs, they would have laughed at you. But this is happening everywhere.

And so I think as building professionals, it's either a case of stick to the vernacular, stick to the 22 degree pitch slab on the ground with a nice big eve overhang, or anything else has significantly more risk attached to it, unless you go with a dedicated specific system, which covers all those ins and outs of it. And the more funky we get,

Jess Kismet (1:23:28)

Mm.

Clarence Macalister (1:23:30)

⁓ the more the risk is of that happening.

Jess Kismet (1:23:34)

It's just another reason to ask someone like yourself early on. If you're going to change up the status quo, then get good advice right from the start from people who understand heat, and moisture.

Clarence Macalister (1:23:50)

Yeah, that's right. And look,

the further you go from those vernacular sorts of construction, drive through a suburb that was built in the 1970s and look at what eight out of 10 houses were built like, that's the vernacular construction. The further you depart from that, the more you need to get good information and understand the risks associated with it. And you said, speak to people like me. And the other thing is I know a lot about certain things, but I'm not for one second going to pretend I know all the ins and outs of everything.

And this is the complexity of the industry now is that whereas 20 years ago, 30 whatever years ago, that there was a go to person about most things, but it is so complex now, the number of Australian standards, the changes, the codes, the materials, the regulations, the local government, the planning, the bushfire. For one person to be on top of every single aspect of that, I don't believe it's possible. I just don't believe it is.

Jess Kismet (1:24:48)

Yeah, well all we can do is our best and collaborate, collaborate together because I mean one person might not know at all but if you get a few heads together you can you can cover off a few more bases. So collaboration is key.

Clarence Macalister (1:25:00)

Oh, for sure. look, I think,

no, that's right. And I think things like this podcast and like just last week, there's there's a roofer in Melbourne, Matt, someone, there's now I think it's Matthew Carland in, Matt Carland in Victoria. And yeah, instead of going home and watching Married at First Sight, go look at some of these videos. Cause the stuff I was learning about roofing from this guy, it's phenomenal stuff. And I suppose that

Jess Kismet (1:25:14)

Matt Calland.

Yeah.

Yeah, he's up there with Sean.

Clarence Macalister (1:25:30)

That's right. And look, I spoke to him a few weeks ago. He called me up about a few bits and pieces. And I think that's the flip side. As things are evolving, we've got this technology and information out there, provided you're getting it from not just some bloke who came down in the last shower, that the amount of information that's available out there from reputable people is significant. And it's good info.

Jess Kismet (1:25:31)

Hmm.

And if you don't know the

answer, the way we all collaborate, can tell you can send your person off to someone else who might know the answer. You know, there's a network here that's ⁓ really full of good information and very robust.

Clarence Macalister (1:26:06)

That's right.

No, that's right. And using these online technologies, I think, can fill a phenomenal amount of the gaps in there. And I've seen some of these conversations on LinkedIn. I had a conversation some years ago where the mighty Joe Lstiburek came in and had his two Bobsworths someone said, Joe Starbrick's told you Clarence. Well, if I'm going to be told, I'll happily be told by him. And that's all good. Happy days. And that's a community that's developed. And that's the thing, even people like Joe who were

Jess Kismet (1:26:36)

Yep. Yep.

Clarence Macalister (1:26:43)

⁓ you know, the godfather of building science will come and jump into a conversation in Australia about something. I think that says a lot about how that community can operate at that level, which is pretty special.

Jess Kismet (1:26:55)

⁓ Absolutely.

Okay, let's move on. ⁓ Let's we've got a couple more questions. mean, geez, couple I've got dozens, but let's start. Let's let's finish off with two.

Clarence Macalister (1:27:05)

Yep.

Jess Kismet (1:27:12)

Where do you see the biggest opportunity for improvement for moisture management and /or roof ventilation in Australia?

Clarence Macalister (1:27:20)

Where do I see the biggest opportunity for...

I would say in many ways that the best answers are right under our noses. And if we go back through a suburb that was built in the, the earlier go back and I drive around Launceston, you see roof vents everywhere. You see eave overhangs everywhere. You see eave gutters, etc, everywhere. So I think a lot of it is in the basics and...

I think the biggest opportunities are going back to the basics and realising that the further we stray from those, the bigger the risks are. everything is possible if you're willing to do the cost, the technical, the knowledge, all the stuff that goes with it. But the further you go, the more you've got to get everything absolutely spot on because there's less redundancy in the system. I think ⁓ going back to basics is really important.

And that sounds a bit ⁓ trite to say that, however, I see really basic things being stuffed up all the time, all the time, whether it's timber durability, whether it's flashings, whether it's drainage, whether it's ⁓ ventilation, whether it's door installation, there are so many of these basics and I think getting those basics where the...

whether you're a house for the housing commissioner, whether you're building an architectural mansion, think getting that fundamental basics is really important. And I think people often get sucked into this, you know, we've got the new tool and we've got the new truck and we've got the new whatever, we've got the exciting uniform, but that the basics will always be the basics no matter what you're building. And I think that for me is one of the takeaways. whenever I...

have someone working for me, I don't care whether it's a roofer or a tiler or a plumber or whatever, I always try to share knowledge with them and get knowledge off them and I think that's gold. ⁓ So that's my answer to realise how important the basics are because that's what it's been built on since the dawn of time.

Jess Kismet (1:29:37)

Thank

And final question, what is the one thing you want everyone to know? If you had to give the entire building industry in Australia one piece of advice, I mean, we've covered back to basics, but if you had to give one piece of advice, what would it be?

Clarence Macalister (1:30:04)

The final question that I want everyone to know is, don't underestimate the inner building scientists. And I know that sounds a bit corny, but the thing I've seen is if you have the knowledge and the interest and the skill and you can network with other people and pull that information together, the amount of problems you can solve is phenomenal. And we're seeing it around us all the time. And I think as builders,

And not just builders, builders, building designers, anyone within that space, the amount of innate knowledge we have around what works and what doesn't work. And it's almost like a sixth sense. Once you've been there long enough, you can look at something and say, now it's gonna work, it's not gonna work. And I think the same thing comes with building science, building physics, building performance, that I believe a lot of people, if you're half motivated, there's a huge amount of passion and skill that you can...

harness together to solve a multitude of problems and don't underestimate the skill that you haven't seen happen multiple times or speak to a guy just today. Daniel Isles up the Northwest coast and it's just a matter of skill, passion, interest, networking, communication, using your background to pull it all together and the amount of things you can solve is really quite phenomenal.

Jess Kismet (1:31:26)

That's a bang on. mean, that's how I have made my job, my career. I started out from very humble building design beginnings and just my interest and passion brought me here. One step at a time.

Clarence Macalister (1:31:39)

Now, and look at,

and I've sort of, you you and I have sort of crossed paths multiple times in the last few years. It's interesting to see how people find that niche and we all start, no one starts as an expert, if we've, me as the scientist is good at explaining things, you as a communicator is good at communicating things. We all have a whole other bank of knowledge. We have that one thing we're special at where we can deliver this.

whether it's teaching, whether it's communicating, whether it's technical, whether it's supervision, a lot of people have that skill we can bring to it. And just another thing, for you doing this podcast, I take my hat off to you and I think it's a wonderful thing. And I was not much of a podcast person until a few weeks ago. I've actually listened to one, Matt Walsh, Matt, who's the guy from?

Jess Kismet (1:32:34)

been

motion.

Clarence Macalister (1:32:35)

Ben Walsham a few weeks ago, I was listening to that in the car and I thought, there you go, this is my new driving tune, is the podcast. So yeah, good on you Jess. Yeah.

Jess Kismet (1:32:39)

Thank you.

That's great. That's

great. I do love I love podcasts and I listen to them all the time, not just work related, but all sorts of different things I learned so much just while I'm driving to and from work.

Clarence Macalister (1:32:51)

Yep. Yep. Yep.

Better than married at first sight.

Jess Kismet (1:32:57)

All right. Well, thank you so much, Clarence, for joining me today. I really appreciate all of your time and wisdom and experience. And I'm sure the listener does too. So thanks again.

Clarence Macalister (1:33:07)

No, thanks for having me, Jess. And look, I just encourage anybody out there to get into it, find the information and use that to your advantage because it's an exciting industry. It's a fascinating part of the industry and there's so much we can all get from it for ourselves, for our clients. it's who'd want to be doing something else,

Jess Kismet (1:33:31)

Yep, right on. All right, cool. Thanks, Clarence. Okay, bye.

Clarence Macalister (1:33:33)

Thanks, Jess. Goodo