“Legally, you can still build a house with no membrane.”

That line from Villy Yordanov, Pro Clima’s Innovation Engineer, sets the tone for this conversation about what is technically allowed versus what actually leads to durable, healthy homes. We unpack the gap between building compliance in Australia and real-world building performance, particularly in weatherproofing, moisture management, and the building envelope.

A big focus is the NCC 2025 changes and how some cladding types can bypass performance solutions. On paper, that can look like simpler compliance. On site, it can create risk if builders assume “compliant” automatically means “safe” or “long-lasting”. We talk about why National Construction Code updates matter for builders, and how small decisions in wall systems can lead to big problems later like leaks, mould, and expensive rectification work.

We also break down what membranes actually do in modern construction. They are not just there to “stop condensation”. They are part of a complete building envelope system that helps control water, air, and vapour. Alongside correct detailing, taping, penetrations, ventilation, and airtightness, membranes support durability, moisture safety, and better indoor comfort. If you are interested in building science, high-performance homes, or Passivhaus and Passive House principles, this episode connects the dots in plain language.

Finally, we look at why warm climates are not a free pass. Tropical building in Australia brings extra humidity and a higher moisture risk, which makes good detailing even more important. The takeaway is simple. Builders who keep learning, understand systems, and treat weatherproofing as a whole-of-wall approach will build better homes and avoid costly failures. If you want practical insight into NCC compliance, membranes, airtight construction, and moisture control in the Australian construction industry, this one is worth a listen.

👇 CHAPTER MARKERS 👇

00:00 Introduction

00:30 Inside Pro Clima HQ Sydney and Building Envelope Systems

02:02 Meet Villy Yordanov, Pro Clima Innovation Engineer

02:29 NCC 2025 Update Risks and Australian Building Compliance

04:14 Cladding vs Membranes for Weatherproofing and Moisture Control

07:48 Roof Airtightness Mistakes and Condensation Risk

11:31 Condensation, Mould, and Timber Rot in Wall Systems

14:31 Building Research, Testing, and Industry Funding

16:57 Membrane Myths, Builder Education, and Installation Errors

18:32 Masonry and Concrete NCC Exemptions Explained

24:16 Steel Frame Ghosting, Thermal Bridging, and Airtightness

27:39 Rigid Insulation Boards for High Rise Construction

31:14 UV Exposure Testing Standards for Building Wraps and Membranes

37:43 Tropical Construction, Vapour Barriers, and Humidity Management

40:13 Tropical Home Comfort Strategy and Moisture Safety

40:57 Why Insulation Still Matters in Hot Climates

42:35 Vapour Barriers in the Tropics: When They Help and When They Hurt

46:00 ERV vs HRV Ventilation Systems for Healthy Homes

48:55 Membrane Billowing, Wind Loads, and Weatherproofing Failures

54:50 NCC 2025 Control Layers: Water, Air, Vapour, and Thermal

01:03:23 Ventilated Cavity Requirements and Drainage Planes

01:07:31 Roof Ventilation, Moisture Movement, and Condensation Control

01:12:01 Sandwich Panels Moisture Risk and Building Envelope Design

01:13:15 Builder Mentorship, Training, and Learning Building Science

LINKS:

Our Sponsors:

Pro Clima - https://mindful-builder.captivate.fm/proclima

MEGT - https://mindful-builder.captivate.fm/megt

CR Kennedy - https://www.crkennedy.com.au/

Connect with us on Instagram: @themindfulbuilderpod

Connect with Hamish:

Instagram: @sanctumhomes

Website: www.yoursanctum.com.au/

Connect with Matt:

Instagram: @carlandconstructions

Website: www.carlandconstructions.com/

Mentioned in this episode:

Proclima Sponsor

Have you ever wondered what it means to build with intention?

Well, I'm Hamish.

And I'm Matt.

And we are dedicated to pushing boundaries and building better homes.

We welcome you to join us on the Mind for Builder podcast, where we are

committed to driving positive change in the building industry by surrounding

you with experts in their field and being open about our lives as builders.

Join us on this mindful journey of construction by subscribing

to the Mindful podcast.

We are at the real official, real Pro Clima studio today.

And

well, is it, it's not really the Proclaimer studio.

It's like we were a Pro Clima HQ in Sydney.

Um, yeah, we're, this is super exciting.

Who

are our sponsors?

I think Pro Clima.

Yeah, I'm pretty sure Pro Clima, one of our

sponsors.

I dunno if anyone's heard of them.

Um, kind of a big deal.

The Now we are, before we introduce today's guest, we are in there.

If you're not watching this by video.

They're starting to set this up as a bit of a pretty cool hub training facility.

So if you are in Sydney, um, actually really in Australia, you're gonna

come through Sydney at any point.

Keep an eye out for this hub.

You guys are, I think, gonna be using it in the future for educational purposes.

It's what, what's really cool where I'm sitting behind me, you've got some

commercial facade systems that you could break it down like a very 3D structured

detail to understand how this goes together than try to draw this on the,

is this the new, the new certified system that you guys launched

for Tex?

Yes.

Tex. Tex Lio.

So that hero on its own, and then a hero with Roco on the outside as an

external continuous installation.

Yep.

Then put whatever cladding we want.

Yep.

On the front as a fully tested system.

Now we have the smartest pro climb employee.

Is it?

Is that, that's what we've been told.

Okay.

Your last month's employee of the month, weren't you

maybe?

No, we are, we have V today, so I think we should say with all the

Pro Clima staff we get on with next day, we tell 'em that the most.

The smartest, but I think you actually are.

So you give Jesse A. Good run for his money.

What's your background, Billy?

Background in mechanical engineer.

Yeah.

I come from Bulgaria and studied mechanical engineering in Denmark.

In Denmark.

How long have you been in Australia for?

Almost 10 years now.

Yeah.

I came as an, as an exchange student from my Danish university just to travel for a

few months here and study and look at me

and now, you

know,

married Australia

wife, still kids.

Right.

So now you know the NC more than anyone else?

Arguably much, much, much more than me.

No doubt.

Maybe in some sections potentially, yeah.

So, okay, let's, let's head down that road straight away.

Mm.

We currently are operating under NCC 22.

Yes.

As of May, we're about to operate under N CCC 25.

Yes.

Depending on the state, I think.

Mm-hmm.

South Australia, the only one that are, aren't implementing this, is that correct?

I've heard Tasmania as well.

Oh yeah.

TAs questioning whether they wanna do it or not.

Okay.

But then it's gonna be frozen for three years.

Minimum.

Yeah,

mini minimum.

So we won't see any changes.

Now, arguably you could say that this is the most dangerous code.

Sure.

Potentially, yeah.

Yeah.

Do a bit a step forward from the 2022 code in some regards.

But yeah, overall,

yeah.

Yeah.

I mean, it's probably important to say that a lot of the things we're gonna

talk about today are our opinion.

Mm-hmm.

So, I mean, like I know, I understand there was a little bit of hesitation

there when we kind of asked you a very sort of direct question about the code.

I think let's just appreciate to all the listeners here that.

We can talk about our opinion and maybe some things that we would

or wouldn't do, and you know, please don't hold us to anything.

Do your own research, do your own, you know, investigations, things.

You sound

like a conspiracy theorist.

They go do your own research.

No, I'm, I'm, all I'm just saying is I understand, you know, we're come really

here under the Proclama brand right now and you know, I just want give you

a little bit of freedom to kind of, you know, speak your mind a little bit

about it and knowing that, you know, please don't hold us to anything,

you know, if it's slightly wrong or,

but, but as we've always said, even though Pro Clima a major sponsor, like there's

something that we'd never align with.

We'd say it openly.

I, we just by chance, we line with everything because they're pushing

the industry, which is why I asked the question, it's the most dangerous.

Do you wanna explain why it could be dangerous?

From what we are, uh, concerned about the weatherproofing side of

things, air tightness, condensation management, weatherproofing took

a big step back in the 2022 code.

So 2019 you had no option.

You had to do a verification method.

You had to do a performance solution at and use the tested system.

What moved from 2019 to 2022 is it allowed certain cladding types, metal cladding

types, and certain timber and masonries to not require a performance solution

and just follow a very prescriptive standard, which had nothing to do with

weatherproofing in the first place.

So suddenly projects could go ahead and install metal cladding according

to the metal cladding code and assume that it was weatherproof,

which was not necessarily correct.

We know that the weatherproof layer is the membrane layer, and those

standards do not have anything about the membranes, uh, requirements.

So from our perspective, that was a big step backwards in the weatherproofing

side of things, where the most damages come to in the first place commercially.

Yeah.

I think, I think what we need to understand and the biggest concept

that our industry gets wrong is cladding isn't the weatherproofing

system and we shouldn't be relying on our cladding to stop water

'cause it will leak no matter what.

So, so I, I'm gonna, I'm gonna ask you a question.

I, I actually know the answer to it.

So, so what the NC 22 is assuming is that the cladding system

is the weatherproof barrier?

Is that what it's assuming

the way the weatherproofing provisions are written?

Yes.

Yes.

And

so what is NCC 2025?

No changes.

In terms of the, the weatherproofing side of things.

So these standards remain as a DTS pathway.

So I, I, I understand as well when we push on some of these questions,

because you, you guys are involved in some of the, the conversations on the

standards committees and stuff like that.

Yeah.

And you, there's probably certain things you can and can't say.

Mm-hmm.

Have they recognized that this is a problem that,

um, my boss, Jesse Clark would be sitting on is the one sitting on the

BC and the Building Codes committees

Yeah.

To, to say better whether they've recognized that or not.

But I sitting, uh, me sitting on the standards Australia

for the membrane standard.

Yeah.

We haven't got there yet,

but, but the conversation's obviously been raised.

Mm-hmm.

So that they're aware then that it's a problem.

Yes.

So certainly the conversation is moving that everyone becomes, uh, aware that.

Pressure is fully transferred onto the membrane.

Membrane becomes the most crucial layer that we need to make sure is watertight

and airtight and membranes have not been testing for water tightness and

air tightness well enough so far.

So, and I think we should break this down in two conversation, tame mm-hmm.

Walls and roof, because

Fair.

Yeah.

Sorry.

You and I stick to two conversations.

Mm-hmm.

Bill your record.

There's like five conversations happening at once, if you're lucky.

So

I've got like four different things written down on paper right now.

Like, I'm trying to work out where we're going here.

I just joking.

So if we, I think we'll start with, I would say the industry

as a broad community of kind of worked out walls, have we not?

Yeah.

Like

residentially, right?

Yeah.

Yeah.

I think, yeah.

I, I wanna stick more to residential Sure.

For the minute, because commercially I, I need to do a bit more prep on that.

Mm-hmm.

Um, but the, what, what I see is, I think everyone, maybe

again, we're in the bubble.

But we understand the quality membrane on the outside, and we

both openly use promera and have for 10 plus years ventilation.

Batten system can't go wrong.

Yeah,

yeah.

Um, taping windows, all that.

Mm-hmm.

Where I see the problem is the roof.

Mm-hmm.

And I think there's a few clauses in this current NCC, which scare me.

Mm-hmm.

Um, but also we still, and I won't use brand specific, you see the

installation that's foil with the insulation attached to it.

The anticon,

you can call it anticon.

Anticon, yeah.

That from my understanding, is probably, well, if you install it now

correctly, it's not doing its job.

Or if you then don't install it.

What am I trying to say here?

It just shouldn't be used.

But if you install it in, if you install it correctly, it's not

having any benefit to the building.

But then why aren't we then looking at complete wrapping a

roof?

Hang, can you stop on that for a second?

Sorry.

You are saying if it's not, if it installed correctly, it's

not having any impact on the thermal performance in the home.

No, it's not.

Why?

Because you've got the Batten system that you've gotta follow the ventilation

system and then the moment that you have insulation with the Batten system and it's

not still there, it's not doing anything.

Yeah, I just wanted to clarify that.

Yeah.

'cause I don't actually think the code, um, also specifies

that you need to put a class four building wrap on your roof either.

If so, let's delineate already.

So if you're talking about Trus roofs where installation

is sitting on ceiling level.

Yep.

Yeah.

So, and the ceiling is not parallel to the roof plane.

Yep.

You can put whatever you want on the top of your roof structure.

That could be.

Anticon fully vapor barrier, or it could be a class four membrane

and you, you still comply.

Okay.

As long as you ventilate that place in the, in the climate

zone, in the cold climates.

Yeah.

So,

yeah.

So how does that, how does that work then?

If you've got a warm roof scenario,

warm roof scenario where you have a rafter type roof insulation between the

rafters and you protect your membrane, uh, your structure with the membrane

and fill the full depth of those rafters with insulation, then that membrane

should be highly vapor permeable.

Yep.

But, uh, so okay, maybe go back maybe to recorrect my statement then.

It's on a pitch rafter of like a, what we would traditionally call a warm

roof, where the anticon then isn't

you?

Like it's

not actually doing anything.

No.

Yeah.

And I know you and I like to shoot can, um, the star rating, but by then

putting, uh, anticon on top of that.

That can then add to your star rating or your R values and your roof.

But the installation has a gag.

It's the air gap

system.

No, I, I understand.

I understand that.

It's, but I, I'm just system, I'm pointing out a floor in the system.

Yeah, yeah.

Because, because you're saying that this is gonna be R one.

Yeah.

Mm-hmm.

And then you are like screwing your roof hard down on top of the

compressing and compressing it all down.

And, and, and we're not, this conversation isn't like around that

Proclama products are the only solution.

Mm-hmm.

What we wanna do is point out the big changes that are coming,

because I go back to my common, my comment is it's a dangerous code.

Yes.

So what I want to, so let, let, let's, this is like, uh, brains are, bring

it

back,

man.

Let, let, let's go back.

Bring it back.

You guys are laughing already.

Um, so the, the, um, the roof I want to touch on, because one of the biggest

changes that we have coming on is that we've got a, we, what, what I

understand, especially the trust roof, and it's currently part of the code.

Mm.

Is we technically can't wrap a roof continuously.

No.

You can't link the wall membrane to the roof membrane.

Keeping an air tight at air tight attic space while keeping your

insulation at ceiling level.

Yeah.

And that, and that's, that's, that's the real clincher.

You do it, but you need to push your insulation to the

underside of the roof sheets

somehow

and Yeah.

Which, which again, then you compromise the installation of the installation.

It's not continuous.

So we have other problems that we introduced, but we're now allowing the

building not to be airtight potentially.

Yeah, of course.

And what issues would that cause?

Well first, you're not allowing the building to be, to not be airtight.

If you dedicate an air tightness controller on the

inside of the structure Yeah.

Fully wrapped three, three dimensionally across the warm side of the installation,

then you're gonna achieve a pretty

intel

Yeah.

Airtight structure.

Yeah.

Intel.

But they, intel needs to run on the underside of your bottom core crosses.

Right.

But.

Let's be honest.

No, that's not the majority of the construction, right?

If you don't do that, yes, you're gonna have a leaky construction,

especially a leaky ceiling.

So hot, humid air will rise up and will find its way through gaps and cracks and

especially downlights and everything.

So it's gonna pass through a thick bat of installation, sitting on the

ceiling level, everything fully air permeable and vapor permeable, and

it to start going towards the code elements of the structure upwards.

That's the trusses and whatever goes at the top, whether that's

the underside of the anticon or the roof sheet straight away.

So, so we can go back, let's even go back a step here as well.

What, what's the, what ultimately is the reason Pro Clima here?

Healthy, durable, and energy efficient buildings.

So durable.

Durable.

Yeah.

So durable's a real key word here.

Mm-hmm.

Because if we're not wrapping continuously, water kills buildings.

Exactly.

So do you think this is a huge F floor on the code?

You can speak on behalf of Vian, not on behalf of Pro Clima right now, if you

wanna Yeah, of course.

It in, in general, building a trust roof in that configuration is

suboptimal building practice, period.

Like this is

by, by having the insulation on, on top of the

plasterboard.

Yeah, yeah.

On top of the plasterboard.

And then allowing air to freely escape into your coat attic space.

Yep.

Um,

have I seen too many damages and stuff?

I don't, haven't been on site enough to see this, but I'm hearing scenarios,

especially in the cold climates where structures rot, mold develops.

Um, we've seen a lot of documented evidence in North America where this

thing can happen when you ventilate that roof, get in that, uh, cold, but moist

air from outside hitting, uh, structures that go beyond ambient condition.

And then you form condensation and mold growth over time on the other

side of the roof sheet or on the other side of the membrane there.

So,

so

not ideal.

So did these buildings have in tallow.

No.

Yeah.

Yeah.

And do they have mechanical ventilation

mostly?

No.

Yeah.

So to make

the assumption that they code built house.

Yeah.

So, so, so which, which then I'd agreed that clause makes

sense for a code built house.

That makes sense.

I feel like if you were to have mechanical ventilation in and in Talo

mm-hmm.

The problem, it's not a problem.

Having said that, there's no way to potential, like your wfi doesn't

give us that three day structure.

Yeah, well that's correct.

We can't do a reliable wfi calculation with a uninvented attic space.

It's a way too much air that can behave radically in real life.

And WFI can't account for this.

Um, the only way to do this is proper real life experimental study.

Like I know some people has done CFD computational fluid dynamics

calculations to assess what might happen.

Sorry, what was that?

What calculation?

Computational fluid dynamics.

You wanna get, do you wanna maybe

comp C, FD?

No,

no, but like, no, for like us.

Yeah.

So this is, um, as, as you assign boundary conditions of this is house, this is

outdoor air, this is air coming in, air getting out, and then you let the

simulation predict how the air movement will behaves in terms of, in terms of

its velocity and temperature changes.

Yep.

It's a lot more, it's, it's kind of dividing everything into small pieces,

um, to assess, sell by sale, what's gonna happen, which is not how Wfi works.

And have you done that on this situation before?

No.

Okay.

I've done this on much larger scales, like assisting ventilation, car parks, or data

centers or stuff like that, not roofs.

Yeah,

I know, I know that cla, I know that Clarence and Mark Bury have done a

lot of work on like existing buildings in Tassie around this, this exact

stuff like real life experience.

Yeah.

Ing the University of Wollongong has been performing some CFD calculations

and trying to link it back to a. Rio building that are experimentally

measuring things and assessing.

Can you open it only on the eaves?

Can you open it only at the ridge?

Do you need to open it top and bottom?

Are these studies funded by certain companies or are

they're actually independent?

Of course they're funded.

Yeah.

Yeah, they

work for free.

Yeah.

Yeah, I know, but like at the end of the day, like who's fund, like who's funding?

Because if that's the,

the steel industry.

Okay, cool.

I'm gonna

show you the well led that the steels do not well led rust.

The, the structure.

Yeah.

Yeah.

So if the information comes out, that's not beneficial to their product.

It's not gonna be, what do we call the blue scope steel rule?

I don't know who exactly the brand is.

Yeah,

I'll say it.

No, I can say that's exactly what was called out the Busy Building

Physics forum a few years ago.

They, they raised this issue multiple times, and I think it

was Mark, I won't, don't quote me.

It was someone kept like, who's funded the study and then

you would see them try void.

He's like, just answer the question.

And it was really confronting when they would say who it was.

And it's like, cool.

And, and, and I, and I understand that some people.

Um, someone has to fund them.

I totally understand it, and this probably goes back to our conversation

with Ariana is like, but shouldn't all these, if you're using a university

to, to a study that then should become public information no matter what.

If you were to do it yourself.

Yeah.

You can hide the information, but yeah.

Yeah.

Okay.

Um, cool.

We, we hit that topic.

Interesting.

Here's a question.

How does, how does pro like a, a company like Pro Klima go

about solving these problems?

Well, first and foremost, it's education.

Like, you don't know what you don't know, and there are many people

that you see in the industry.

Um, architects and designers who I find are still confused of the

role of membranes in, in buildings.

They said, I'm, I'm putting a membrane to stop condensation.

Okay.

We we're talking in tele maybe, but you're not putting an external

membrane to stop condensation.

This is kind of the, the biggest misconception I find.

You're putting that membrane.

To protect that structure.

And the risks of condensation are much, much, much lower compared

to what it used to be back in the day when that membrane was a foil.

And this is where I get back to the durability.

If we're gonna start leaving bits and pieces of the membrane off

mm-hmm.

Yeah.

We might allowed to vent, but you know what's gonna happen?

Water's gonna get in.

Yeah, exactly.

And this is,

and wind washing too.

That's, we haven't touched on that

topic.

Yeah, of course.

Um, and talking about the mo, the code being dangerous, like the words

membranes, it's a deemed to satisfy pathway for weatherproofing, if

you choose to use a membrane, means you don't need to use a membrane.

So you can still build a house with no membrane, walls, or roofs.

When you, when you say no memory are, you're talking about like

a class four building wrap.

Yeah, yeah.

That's what

mean.

Yeah.

So you can still choose to build a house without it.

Without it, yeah.

But

which makes sense.

Like think about hemp.

You built, you built.

A hemp house.

Yeah, but he, yeah, but that's probably that you're probably gonna have a

performance solution based off that.

Yeah,

yeah, yeah, yeah.

Yep.

A hemp is gonna be a performance solution.

The masonary and concrete buildings will be exempt from

the condensation provisions.

Wait, wait, wait.

What?

Why they masonary and concrete?

Why they, ah, yeah.

The physics don't apply to concrete.

I dunno why they're not, uh, it's saying it's

pretty you folks.

Physics does not apply to concrete.

So wait, but the brick,

so, okay, so, so does that then, okay.

I can understand why they might do that.

'cause you've got wa which builds double brick,

so they wanna just, which kind of makes sense.

It's just the big companies wanna protect their product.

Let's just say it.

Yeah.

Oh yeah.

Um,

we're not saying which ones.

Yeah.

The thing is, if you start talking single skin masonry, so what's

your interpretation of this?

Brick venet.

Brick vene.

Yeah.

But

that's,

yeah.

Do you need to protect the frame?

Behind the brick vene construction.

Yeah.

'cause you've got, if it's an unsealed brick, like an old

porous brick, the pressure's gonna push moisture from out to end.

Of course.

Yeah.

That happens.

It's gonna push that moisture in.

It's obviously a structure is fully exposed, uh, during

construction to start with.

Yeah.

And then you have, we holes that equalized pressure straight onto whatever the

next layer is, which is a pla bot.

Right?

Yeah.

Um, also you have gaps and cracks and around the window open, uh,

window penetrations and stuff that you Not with the Pro Clima

products.

Yeah.

You use the

prom.

Yeah.

Yeah.

But no, we host that water can be driven inward somehow at some point.

Yeah.

Yeah.

We're talking specifically about a brick veneer right now.

Yeah.

Yeah, yeah.

Yeah.

Yeah.

Then what about concrete Precast Concrete institute?

Concrete block work, permanent stop.

It's still porous.

It's still quite porous, but this kind of constructions do not have we holes

do not have drain and ventilated cavity.

The concrete is the structure, is the aesthetic.

Is the weatherproofing all in one goal?

So whatever is on the inside of that is technically, uh, protected.

However, people want to keep that concrete look on the outside and they

put the insulation on the inside, and this is where you have the most dangerous

situation internally, insulated concrete with nothing to, to protect your

concrete meaning hot, humid, air from outside past the installation, gets into

the code, concrete face straightaway, condensation and lots of mode.

Would it, would it not be more of an issue from the inside with, with

the condition air from the inside then coming and meeting, I guess

that internal face of the concrete?

Exactly.

Yeah, that's the problem, yeah.

Okay.

But this is why the statement says you don't need to use a membrane there,

because what the, the, the idea of membrane in the code away for now is that

sits on the outside of the installation.

So you have concrete installation, putting a membrane on the outside of

that installation will not do anything.

You're not protecting anything because your concrete is fully sealed up.

It's protecting your structure.

So putting that membrane is a impractical.

You can't do that and B, it's not gonna be useful at all.

So it kind of giving you a free pass to not do anything.

So that scenario, to make that scenario safe, where you've got

insitu concrete and then an insulated wall on the inside, would you then

be suggesting that use in intelo

a hundred percent in the code of climates, you can't make that wall work

without an internal vapor controller?

Yeah.

Allowing so much in and, and

especially now that concrete buildings are becoming a way more

airtight, the way that we build.

Yes.

So in a more initiative, people start cooking and showering.

That m has gotta go somewhere.

Yep.

Theoretically build the concrete, install the windows and seal them up.

Do a blow door test.

Now put your in, intelo in after your frame and installation is in, do in

Intelo in and do another blow test.

Blow a door.

You're probably not gonna see any difference.

It's equally as air tight.

So you are saying in this situation it should, so from outside to inside

should be concrete then in intelo, then in installation or then or

concrete installation in Intelo.

The ladder.

Yeah.

Yeah.

Concrete installation.

Intel.

So that intel stops the air.

Yeah.

And vapor migrating through the installation, hitting the concrete.

And this is the most compromised scenario.

Like we need to understand that this is how Wfi was born in the first place.

Like when Germans started renovating heritage buildings

and they started bringing energy efficiency to the equation.

Of course they wanted to keep the look of the old masonry on the outside.

Yeah.

The only problem, the only solution was to put the insulation on the inside,

put it on problems started occurring.

They get involved with the building physics side of things

to assess why this is happening.

And that's where Wfi was born, to assess the movements of

moisture and how to solve it.

The ultimate scenario is.

Put everything on the outside to keep that concrete warm.

So you go back to the conversation before, what did you say?

That you can't have an air tightness on the outside of the building.

What'd you say?

You said something along,

ah, you need to have the membrane being watertight and airtight on

the outside to pressure equalize.

Yeah, yeah.

The pressure.

Yeah, because you, well, ultimately if we, if we built completely

airtight, like I, um, to me, imagine a building, everything's

fully sheathed and fully adhered.

Mm-hmm.

That's perfect.

It's pretty airtight.

And then you insulate then on the outside of that,

yeah, that's the,

like it could, yeah, you could use a rock wall that you got

behind you, or wood fiberboard

wood fiber on the lower rise buildings.

No problem.

Yeah.

Yeah.

It's a good solution for sure.

That's

the ultimate.

Mm-hmm.

So we've got, we've got two scenarios behind us, both test certified systems.

Yeah.

Um, I understand external rock wall.

I'm actually pointed behind me and there's, there's two, you

know, two stands behind me.

One's got external insulation on a hero.

The other one is, doesn't have external insulation like.

Intuitively, I'm looking at this one here without the external

insulation with a steel frame.

Mm-hmm.

I understand why it's steel.

'cause we got it's commercial.

Mm-hmm.

Um, in my mind that's a risk of condensation.

Is it?

I dunno, it just in my mind, if you've, you in,

on the inside.

Yeah.

So

let's, yeah.

But, but I'm, I'm talking about like, is that, is that still

frame gonna start condensating?

So let's, let's think about what happens.

Yeah, that's

a good

one.

Okay.

So the, the, the, the risks of condensation are there, but the more

problematic part here is thermo bridging.

That they're gonna occur through the thermo, through the steel, right?

Yeah.

So if you imagine a two, uh, a thermal calculation of this, you have the

steel frame with insulation in between.

So the, the path of heat resistance through the insulation is much harder for

heat to escape than through the steel.

So actually the steel access, a hot bridge if winter, hot, warm

inside, cold outside, you losing a lot of heat through the steel.

So actually the outside of the steel, the where it touches the

membrane or the board is warm.

Is warm.

Okay.

So the risks of hot, humid air heating, that is

interesting.

Lower, technically the problem.

'cause it's

warm.

' cause it's warm.

'cause you're losing heat through it.

Huh.

However, the inside of the steel frame is colder on that plasterboard layer.

And if that's too code, then you're gonna get something interesting.

So you get what's called ghosting.

Yeah.

You see images of black stripes across the plasterboard.

Yeah.

So the code steel allows and this is interesting.

Okay.

So getting a little bit, I love this nerdy physics here.

Okay.

Yeah.

This is

good.

This is this.

So when you have a cold strip, suddenly you start seeing black spots.

Yep.

Where, what are these black spots?

Initially everyone thinks this is mold.

Yeah.

Water.

Water.

Where are from

the condensation from the, well, the inside the.

I

if it's really bad, potentially it's gonna get there, right?

It's gonna be so cold on that steel.

That hot, humid air is gonna hit that spot and condense in all long-term form

mode initially on the back of the plaster board and later on it's gonna propagate.

But what you see on the internal phase of the plaster board is a black

stripe is actually dust particles.

Okay?

It's dust particles from the air.

Especially if you people are smoking indoors or burning a lot of candles.

All these fumes will get attracted through the cold surface due to a phenomenon cold.

The Brownian motion, okay, you want a bit of history here, brown and

somebody, brown was actually a bot.

Botanist.

Botanist, yeah.

Botanist, yeah.

Not anything to do with physics or chemistry.

Yeah.

Then he found out through whatever he was doing with plants that when things get

cold, nature naturally slows things down.

So this is what causing, uh, this problem.

So the surface is code.

Therefore movement of stuff in the air wants to slow down.

And that's how the dust particles that they're actively moving in the air get

attracted to a surface and stay there.

Huh.

So we have some pretty smart people in this podcast.

Wow.

I don't think we've ever had something so smart.

Yeah.

And look, and I didn't and I, I brought that up before not

to try and catch anything out.

'cause I know that there's a lot of research that have gone into

these two certified systems.

Yes.

And let, I just want to re you know, reemphasize that these a

durability, not an energy efficiency perspective.

Yeah.

Dur,

yeah.

Durability.

So Pro Climas obviously not gonna

put their name on a system if it's not gonna work, but mm-hmm.

As I said, I look at that and go, oh, that's a thermal bridge.

So it's really interesting that, um, that you'll consider that

outer edge warm because of the habitants inside or living inside.

Yeah.

Okay.

Interesting.

But we can go through why, why we are here.

So where we are today in the commercial level side and mostly what, where

re is you have flexible membrane on the outside of a structure.

Yeah.

Flexible membrane.

Once you go really high in the buildings and especially in the high

wind zone scenarios, these membranes, pillow in and out quite a lot.

Yes.

You're gonna risk the every time that membrane is secured to the frame somehow

via fastener to pillow in and out.

This

is a great, yeah.

Okay, so

let's just finish this and then we can Yeah, no, this is good.

Yeah.

So to to account for this, we are moving on to a rigid board scenario.

You put external grade non-combustible boards, is

that the

c?

It's either the c weather defense, external grade gypsum, or any of the fiber

cement products that could be put as well.

So this is what, uh, gonna, where the pressure is gonna

land from that building, right?

The wind, it's not gonna allow any pillow in and out.

That port on its own is not weather tight.

Obviously, to start with, you need to tape every joint of

every sheet of, of, of board.

But we know this is not enough from experience.

The New Zealand, there's the North Americans, the uk, we see

that simply taping is not enough.

You see corners keep chipping off boards crack, especially when buildings move

or excessive pressures hit the building.

That's why we put full adhesive membrane full coverage of that board

everywhere.

So, so the here has more flexibility than say, the Asana?

No, no, not really.

As you use, it's like the sheathing, it's like the structural bracing essentially.

Yeah.

But the the, the board itself doesn't deflect.

Yeah.

Okay.

It all underwent.

Yeah.

So this is where we wanna move as the next step from the flexible system

and high pressure, high high-rise scenarios to a rigid board system as

a more durable weather tight solution.

And we still keeping frame.

'cause that's when the only thing you're allowed to build on high-rise.

And once we get that going, then we look into the better way of doing it.

And that is by putting the insulation on the outside to mitigate the effects

of thermo, bridging the steel causes.

Yep.

Yep.

So, so the major difference between the two systems is that the one with

the external insulation is, is focusing on thermal performance, whereas the

other one is just solving a problem.

Exactly.

Yeah.

So that's the weather tight side of things is the, yep.

Fully tight.

So once you add the Roku, you can, uh, take the four main adv main advantages

that you're gonna see immediately.

First, of course, thermally, it's gonna be much better, you have more installation

and you've mitigated the thermal.

Bridging The wall performs much better thermally.

Second, you've actually improved the weatherproofing,

whether you believe it or not.

Um, it's, you almost don't get any water past the waterproof,

uh, the wall rock layer.

And of course, two more things we rarely talk about, but this is fire

resilience and acoustic performance Yeah.

Is also greatly improved as well.

So, and, and what, like, what would people normally be doing in this scenario?

Because obviously this is a certified

systeming.

Yeah.

So what would you normally see here?

Steel.

Steel frame and then what Matt says.

Yeah, like what, what do they, what would you normally do if

flexible membrane on the outside of the steel frame?

Like what's a flexible

membrane?

Like

flex could be the asana.

The last four extra.

Yeah.

Okay.

Yeah.

For majority of the projects that we see, yes.

No, but could be any cheaper alternative competitors that,

and I think the other thing to mention that makes it is really

important is the UV exposure.

Yeah, of course.

So like, you guys have 180 days.

180 days

tested.

Yeah.

And

what I learned during the week is that it's not the, with your one, and you can

correct me here if I'm wrong, with the 180 days, the water tightness won't change.

It'll stay pretty well.

It actually just loses its air tightness.

Is that correct?

After 180 days?

Mm. Good question.

So let, let's, let's, uh, dive a little bit deeper here.

So first, what the requirements in the, about.

Uh, membranes and tested before and after uv.

The 4,200 part one standard is very vague around that, puts it

in a chamber for 500 hours and doesn't equate this to real life.

So actually following brand protocols for now, but I can tell you, being

on the standards committee for the next revision of the 4,200, we are in

much deeper conversations on how to make this a lot more relevant to the

industry and, and how to make it better.

And there's a lot of brands out there claiming 180 days

that aren't providing testing.

I don't know.

You can't comment on that

exactly.

No, but the, the, the thing is tested to what is what everyone is gonna

question and you can technically say whatever you want if you're not, um,

tested to Matt and Hamish's standard and we say it's 180 days.

Yeah.

So,

yeah.

So, okay, we tested, but what do you need to do before and after you, you

test your unaged material, so brand new from the production line, you age it.

Naturally or artificially in the chamber.

What do you test after?

Currently, you only ask to test one of two mechanical properties for either

tenile strength or birth strength, where a boat push pushes through the membrane.

So you look pretty big.

You've been at the gym.

Do you sit there and you punching

them?

You need to make sure that the, the membrane retains 85% of its strength,

and if you do this, you technically pass.

But for us to, to, to follow the brand's protocols, we had to

prove that both the unaged and the aged did not, did not leak water.

So maintain its water resistant properties, um, remained its strength

for all strength parameters and also maintain its area is air resistance.

Now this is a big can of worms air.

The way we test air resistance is very outdated.

The test standard for air barriers is.

It is meant for old paper-based products, which were expected to have

some form of air leakage through them.

So when we test any of our products for, according to this air tightness

test, we get like below 0.1 means that you, you can't measure anything.

Nothing leaks at all.

So let's say to pass this test as an air barrier is very easy for our membranes.

Yeah.

That's why, again, this is another thing we're looking into

putting a lot more relevant and applicable air tightness standards.

So going back to your statement, does the membrane loses its air

tightness capabilities after UV aging?

I don't think so.

It still remains a good water barrier.

It still remains a good air barrier.

What happens is it becomes more vapor permeable.

'cause the UV to a certain degree degrades the functional layer on the inside,

which is the most resistance to vapor.

So it kind of becomes hyperpermeable class four membrane, which by the way

brings you to a very important uh, topic.

What about the tropics where.

You need a vapor barrier on the outside, but then you a class two vapor barrier

and you expose it for 180 days and suddenly this thing became more permeable.

So not class three, maybe even class four.

Membrane becomes um, one how for even one quarter of its vapor

resistance, suddenly you're wrapping up buildings in the tropics that

does not perform like you wanted to, to perform with the vapor barrier.

Can we?

So Jesus, this is awesome.

I love it.

So two parts here.

Let, let, let's go into tropics in a second.

Yeah, sure.

With the membranes like hype, have you guys actually tested it and go,

when did it, like, would it fail like actually really fail because

you got like your 180 days and know that's what you guys guarantee?

I'd be confident last year.

Have you actually ever tested to be go like, oh, it would still perform

well after four years out in the sun.

Like I know you would never commit to that.

Have you guys just for shits and gigs.

Um, so first.

To do this in real life.

Oh, to get a better understanding, you better put it in real life because a, to

do such a long duration in the machine is gonna be very expensive and costly.

And um, also, it's gonna take a long time.

So I can tell you what's happening in, in Germany from one our founder, curiosity.

Yeah.

We've had some of the mental products, specifically the roof product.

Yeah.

Sitting on the roof for many years and then every now and then at the

one year mark, at one year and a half, at two years, they cut a small

piece and go and test what happens.

Yeah.

It's been many years before.

They might see that it no longer holds the water.

And by the way, by holding water.

I'm trying, I'm referring to.

Australian standard asks you to hold a hundred mil head of water

one KPA German standard asks you to hold 10,000 mil 10 meters of water.

So that's, imagine like A-U-P-V-C pipe that's 10 meters high.

Yeah.

Full of water compared to a hundred mil.

A hundred mil, yeah.

For 24 hours.

What?

Yeah, the requirement with the requirements we pass water

barrier are a hundred times more than what we need to pass.

So,

so hypothetically it would last another hundred times past that

for the Australian standards.

Ah, I dunno if you can do the same.

Yeah, I know, but like,

and, and the products that we're getting here from Proclama, those products that

are being tested to those standards.

Yeah, of course.

Yeah.

Because these products come from Germany, tested to the German standards and Yeah.

Yeah.

So they're not, they're not a hundred percent tailored to our

market, like the actual products.

These are the pro, these are the actual products that are

getting tested in Germany.

Yeah.

So the same ment that I'm buying in Germany is the same ment I'm buying in

New Zealand, same ment than buying here.

The Asana is slightly different because first they don't do much,

um, of flexible stuff on the outside.

And if they do, they may be using some of the mental products.

Exa was specifically developed for the Australian market.

Okay.

Just to be Blue, New Zealand, Australia, and New Zealand.

But yeah.

So now heading back to the tropics, and now you've got another good point.

And sorry, just on the color.

Is the, does the color mean anything?

Yes.

Um, not much.

Um, perhaps thermal efficiency.

Temperature could get in, uh, during construction, like for

the, um, oh, what's the term?

Oh, what

am I about Reflection.

Yeah.

Reflected.

That's, yeah.

That's the

very little, like when you put a cladding on the front or a roof sheet

on the, on the roof and you have this air gap, a little bit will be reflected.

It'll only make sense if it's very shiny.

It'll only make a big difference.

This is very shame.

So we

can get pinks and yellows and oranges.

You can, yeah.

Lighter, lighter, louder, lighter colors don't perform as well.

Not perform as well under uv.

Yeah.

So then you can get, might get, uh, more damage from uv.

Um, but then

from the opposite, like the black would attract it,

then the, the new problem, if it's black, it gets too hot.

Yeah.

If it's exposed for too long.

Yeah.

Yeah.

Okay.

So you want to kind of find the middle ground and say sometimes

lighter black, darker grayish into dark blue is what, uh, works best.

So now back to the tropics.

Yeah.

We, when you talk about like, if they're extending out, they're becoming

even vapor, more vapor permeable.

Mm-hmm.

Now we don't build on the tropics.

And I find this fascinating 'cause we don't, you, you kind of wanna learn, but

you're kind of not forced to being from Victoria to, to building their climate.

Yeah.

But I actually find it, and I constantly say it's like Queensland live like New

Zealand is probably 10 years ahead of us.

Mm-hmm.

Who are like 30 years behind Europe.

Queensland's another 30 years behind Victoria.

Oh, probably, yeah.

Like they're still stuck in the dark age and Hello?

All

our Queensland

Austral.

Yeah.

I think the spice girls just come out in Queensland.

So, uh, but the tropics I want talk about, 'cause there's a whole

misconception that like, oh, we don't, we don't need to worry about this stuff.

We got warm weather.

But you're dealing with a completely different problem.

You're dealing with humidity.

Yeah.

Loads of humidity.

Yeah.

Yeah.

So you wanna sort of more go into deep, do you wanna nerd out on, is

it d What's the It's a blue plot.

Uh, the green product.

The green DA product.

Yeah.

Class two vapor barrier.

Uh, yeah.

Class two.

Vapor barrier technically.

And what's the diff So what class two means it's less vapor

permeable compared to class four?

Yeah.

Much, much less

So, less vapor moves through.

So going back to the old days, like a silver sharking, they

all basically favor blockers

Class one.

Most of them.

Yeah.

Until they started put putting holes in them and they became class four.

Right.

So perforated four would be highly perme.

Vapor and water will go straight to the house.

Yeah.

But so stupid not perforated.

Yeah.

It's a, might be a complete Oh,

20, 20 years ago, you're just like, you, you could tell the difference between

the two wraps by saying, oh, the ones that go on the wall has the holes in it.

You don't wanna put them on the roof 'cause water will get through.

I'm like, and that just seems so normal 20 years ago.

Yeah,

but you still use the ones on the roof, on the

walls anyway.

Mm. Uh, I mean, prob probably

tropics is so challenging.

And to be honest, we had hard to conserv the father of Wfi, like, uh, the,

one of the best building science, uh, scientists on the planet coming in from

Germany with 40 years of experience.

And I also asked him a few questions, Hey, would you do this or this in the tropics?

And I was expecting a very concrete answer.

Said, yeah, of course.

No terrible.

He said, I dunno, I need to try, I need to calculate, I need to see what it is.

There's no, it's not a such a simple solution.

The reality is it's so humid and you have to choose how uncomfortable

you want to be on the inside.

If you don't, if you can sleep at 30 degrees indoors, 80% humidity, and

you feel refreshed and optimal human the next day, keep going that way.

But if you wanna be normal person and to meet normal 21st century

comfort levels, you kind of wanna stay at optimal conditions indoors.

Right?

No more than at least 25 degrees indoors and reasonable humidities.

How do you stop so much hot, humid air from outside coming in?

You have to have an airtight structure, and you have to have an air

conditioned envelope on the inside.

And a dehumidifier, like a constant dehumidifier and

de dehumidifier.

Yeah.

'cause you'll not be able to reject it just by reject that much moisture just

by the, um, air conditioning on its own.

Yeah.

So like what, what purpose then does.

Insular or suppose insulation, playing those cool co uh, warmer

climates like that because you really, the thermal resistance is

just, is not gonna do anything.

It just,

well, let's think about it.

Four degree 40 degrees on the outside.

Yeah.

Yeah.

And you want it to be 25 on the inside.

So let's, you're trying to keep, you

need

insulation.

Yeah.

You're trying to

keep the heat out.

Not the cool in

to call in first, uh, second lowest thermodynamics.

Yeah.

Hot goes to code.

Yeah.

So the hot wants to always come indoors.

Yeah.

Yeah.

So the hot wants to go to code through your building.

It wants to infiltrate in.

Right.

So you wanna stop it moving by air movement to start with.

Right.

So putting an air tightness there on the outside of the structure

to stop that air coming in.

But also that's one way of heat transferring through

conduction by air movement.

Right.

And another way is through

radiation,

conduction radiation through the sun.

Yeah.

Then, then you shading and you learn

something from cam, I say.

Conduct.

So convection is air movement, radiation.

That's where your shading becomes important, your thinking of your

glass and how much glass you have.

And then the last one is conduction, like touching a whole glass, a cup of

coffee and feel your hands growing.

If it's 40 degrees outside, it means it's 40 degrees in your cavity, which

means you're gonna conduct through most of your walls, 40 degrees to 25.

So you wanna resist this.

So actually having the installation there, it is quite important to, to,

to let you use less air conditioning indoors to maintain your comfort.

So it's all or nothing really either.

Keep it very leaky and insulate or proper airtight and

yeah.

Well, uh,

and tell me

about, tell me about, so Pro Clima, I think Jesse's study,

the, um, Australian study says that like in Victoria, in most

parts of Australia, we're using.

Internal.

Mm-hmm.

Um, vapor control, external weather, resistive barrier.

Mm-hmm.

But up in the tropics in certain, um, uh,

CL zone

climate zones.

Yep.

Yep.

Uh, Jesse's saying one,

no Intella.

No intella,

yeah.

Only rely on the exterior air.

And can you just like explain it to me like I'm a 11-year-old?

Why I wouldn't put Intel on the inside course.

That's kind, that's challenging.

Yeah.

Because I fucking told you.

So,

so here is the concern.

So 11-year-old, let's explain humidity variable diffusion.

I've got, if you can, I've

got the, I've, I've got the maturity of 11 year olds,

so we know how Intel works.

It works that the.

Higher the humidity is the more vapor permeable it becomes.

Yes.

And the lower the humidity is the more it stops the vapor.

So in the colder climate, it stops the vapor getting out.

In winter when you're heating your indoor space

and then a and then a ventilation system deals with the extra ventilator

and extra condensation inside.

Yep.

And injecting moisture.

Yeah.

And then in summer that moisture may come within the structure from outside inwards.

Intel opens up, becomes more permeable, lets that vapor diffuse

through and then the ventilation system reject that moisture.

Now at its most vapor permeable state in inte is not infinitely permeable.

So if you have so much vapor from the outside trying to come in

from outside heating essentially a not fully permeable surface

concept,

you can trap some of that moisture behind the, in inte and

within your installation there.

So the risks are very low.

Compared to what they used to do back in the day, specifically in

North American climates where they wrapped the building with plastic.

Plastic.

Yeah,

yeah.

So they're still doing

that though, aren't they?

They still do it in the super cold climates and still problems.

Yeah.

So, I dunno if I told you this.

I worked in Whistler for,

yeah.

Oh, in Whistler.

A couple.

I need to go there.

Mountain

biking.

Yeah.

Uh, it's incredible.

We'll talk about biking afterwards.

Yeah.

Um, yeah.

I, I was on one of these big beautifully, you know Yeah.

Real chateau.

Yeah, Chateau, like big steep bruise up and stuff.

And we started wrapping everything in plastic.

I'm like, what are you doing?

This is like blowing my mind.

Mm.

And they still do that.

Yeah.

But now knowing what I know, like these multi multimillion dollar buildings

that are sitting, you know, at the foothills of, or the base of Whistler,

have probably got massive mold issues

in the inside the walls.

Yeah,

yeah,

yeah.

But you, they're not breathing that in.

Exactly.

Because it's covered by plastic.

So they know as only if you've figured out how to install it well

and seal it up, it's all contained within, but it's not what you want.

No,

not what you want.

Yeah.

No, because could it be degrading the frame?

The frames big

time.

Yeah.

The installation will start, will shrink depending on the type of installation.

Anyway,

I hijacked that part.

Yeah.

But so mold needs food source.

There's obviously moisture coming in there so that moisture

become dry rot and rot out.

The mold's not gonna degrade the timber.

It's the dry rot and everything as it comes.

Is that right?

So,

so just back, back to, back to what, why, why we remove the intel though.

So, so

the Intel's not fully vapor open and there's so much moisture trying

to move through that wall assembly.

Some of it can get trapped.

That it can be trapped.

Yeah.

Yeah.

Some it can trapped, it's like a highway.

It's

a, it's like a big highway that's just blocked up

pretty much.

Yeah.

That's a good way to think about it.

Yeah, that's a good way to do it for an 11 yard.

Yeah.

Yep.

Great.

Okay, cool.

Um, so then, so remove, remove the Intel, Intel internal system and then rather

than, uh, have an HRV, we've got an ER.

Anthrop,

this is good End

and is anthrop

Entropy.

Entropy.

Yeah.

Entropy based core.

Yeah.

Yeah.

And I, I thought this was the right thing to do, but some recent conversation

with some sustainability engineers and pacified consultants there.

Tell me that sometimes perhaps drown specifically or the really high tropics

AR areas, ERV all year round is good, but they find around the Brisbane

area, which is exactly around the time where we, around the areas where we

are not sure where Intel is a good thing or a risky thing, is also they

find that ERV might not be as good as HRV core in the winter months.

Specifically.

They're finding that sometimes too much moisture is being, uh,

lost during the quarter months.

Yeah.

Okay.

So, so it can get quite, yeah.

Actually ask Cam, because.

The past, like my house, it's actually a bit more humid than I thought.

Mm.

But it's been humid.

But Cam said it's a numbers game.

Yeah.

So you need to look at it that maybe 30% of the year you need an ERV.

Yeah.

70% of the HIV.

So you take the 70% win.

Yeah.

Okay.

Or if you are bothered to monitoring stuff, swap costs.

Is it the exact same unit?

Yeah.

You just need to open the co take, take one and put the new one in.

Not the new one, but

I've got a Zenda Q3 50.

I can just swap my core over and that's it.

Yeah.

Oh, I know.

Joel,

how much is,

how much is a new call though?

Isn't

like three grand?

I'm not sure.

I have no idea how much

I can say.

It gets more comfortable, like comforts, I can say It gets quite humid.

Yeah.

But are you splitting hairs though?

No.

No.

It gets quite it.

I'm sitting around 60 up up to 70, 80% humidity internally some days.

But in Melbourne.

In Melbourne, in a passive house.

But

hang on here, I'm gonna, I'm gonna challenge this for a second.

Do you think that's gonna change as your structure dries out though?

'cause you are, you've been living in your home for, what, six months now?

No, but outside's also been around 90.

Horrendous.

Okay.

Well, I mean, that makes

sense.

Yeah.

Because obviously I can't go from 90 down to 40.

Let's see what happens

in the winter.

Yeah.

But it'd be so, I mean, our, our hemp creek passive house stayed humid for a

long time as the big hemp walls dried out.

Mm-hmm.

Now, I haven't chatted with the client since, and Nelson, if

you're listening, let me know.

Mm-hmm.

Um, it'd be interesting to see where that seed now, 'cause it took a long time.

Yeah.

You've got a

huge amount of moisture.

Took a long time for that to come down and dry out.

Yeah, that's true.

One side.

But also, yeah.

Being so hot and humid outside, you're constantly bringing

that, uh, humidity, inwards.

And you're dehumidifying Melbourne

because you're opening the door and

closing the door and Yes.

A, a better, yeah, a better idea would just be to put a

dehumidifier in the house.

Yeah, but dehumidify also heats up the hole and if it's too hot and you heat

it up more to dehumidify, you need to use more air con to keep it comfortable.

Yeah.

It's, you can't win.

Yeah.

It's quite challenging.

Yeah.

So we, you talked about pilling before.

Pilling of the membrane.

Yeah.

Do you wanna, do you wanna explain what that is quickly?

Yes, of course.

So I mean, if you think about it, if you put a, a piece of cloth in between

two standing members, if you blow against it, it's gonna deflect in.

If you blow from the other side, it would deflect out and it's gonna act

like a parachute in and out between these two supporting structure.

And, and that happens on a residential building too.

Um, on the low rise of course depends on the winds that hits that building.

So

just like, just a, a normal mom and dad house, double story

normal ma it really depends what's around you.

If it's like a house at the top of the hill with nothing, no trees,

no other houses around it, it'll experience a lot of this stuff.

If it is a house in secluded within a small suburb with lots

of other houses around, less so.

But still, you experience.

Something along one kilo past cost of pressure, which is at the 600

stat spacing, is enough to deflect that membrane in and out a solid.

So

this 20 mils,

even with cladding, 20

mil

cladding doesn't make any difference.

We have that, uh, a cavity that's open, top and bottom.

Ah, yeah.

There's no pressure on the cladding.

The wind goes past the cladding, past the host straight onto the membrane.

It's a 20 millicom.

So I'm, this is kind of, I'm setting this up for a loaded question.

Okay.

But, so because I won, I'm massive advocate on my own

house, we applied everything.

Okay.

And membrane it.

So like I'm big on using the sheathing as a full structure.

Mm-hmm.

One thing I've noticed, I have not had one arc or tray anything crack and move.

And usually we notice, I've noticed in a passive house, and I found

very early, you see the, you see the skirting in the corners coming

apart a bit more quicker than I've ever noticed, um, compared to it.

I dunno if you've had that problem ham

all the time.

Yeah.

Like,

it actually comes, in fact, I, I, and I say to clients, Hey.

On our three month defect liability day, we're gonna come back and we're gonna,

we're gonna touch up those arch trays.

'cause they'll, they'll open up slightly.

Yes.

Or they'll crack, they'll slowly

crack.

I haven't had that to the slightest fleet now from

Bridge Point and just, and just, and just for any potential homeowners listening, we

actually glue our Midas together as well

and shoot them if you can.

Yeah.

But you just, and you just can't stop it now.

It's so that's one thing I've noticed and I've had the same problem, especially

when we did Wainscoating Problem, big problem was coming apart everywhere.

And I mean like you just saw the lines.

It wasn't like a five M gap.

You couldn't slit a piece of paper, but it's noticeable now.

Peeling, what I'm getting at here is if it happens in a mom and dad house, what we

have done in the past, and this is where I get to now, is our vertical battens

and that we're using everyone seeing, starting to try safe costs on material.

They're cutting little blocks.

Mm-hmm.

On those corner, those little blocks are sharp corners that usually

extend past the side of the stud.

Mm-hmm.

If that peeling becomes 20 mil, are we gonna start ripping our, me our membrane?

Very common in the brick thigh of brick veneer, like it's same things.

Happens even worse.

A bit more exaggerate.

'cause it's a metal face.

Yeah.

Brick tie with the very sharp corners on the end.

When the membrane starts spilling out, it pokes a hole straightaway, like very easy.

So with brick veneer, we should then be looking at a minimum of they've

got those plastic wass or you should be putting on a timber vertical.

Batten, or I put naec behind, I put naec behind all my brick or ecstasy.

So

we, we, we've got a project coming up.

Big home, lots of brick everywhere.