107 – Why Renovators Should Be Aware Of Mould

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mould awareness

In this episode, I invited Andrew Savage as my special guest to discuss and share his knowledge about mould. This topic is not quite pleasant to everyone but it’s very important to renovators. Andrew is a Business Development Manager for Architecture and Design in New South Wales and he will share how mould grows in houses and buildings, why it exists and how to address it.

Listen to Episode 107– Why Renovators Should Be Aware Of Mould 

Podcast: Download (Duration 38:00— 52MB)

Episode Highlights

  • [00:00:29] Renovation Bootcamp
  • [00:02:41] Andrew Savage’s business role
  • [00:03:32] Growing up in a 1960s house
  • [00:04:26] Different causes of mould
  • [00:05:50] What happens when you insulate your home
  • [00:07:51] The big issue
  • [00:08:52] Interstitial mould problem
  • [00:10:50] The stuff you can’t see when it’s inside the wall, often you don’t know it’s there
  • [00:11:35] Mould is dangerous to your health
  • [00:12:30] How to address the mould problem
  • [00:14:10] The two step process
  • [00:15:20] The problem about building wrapping
  • [00:16:45] Types of wall wrapping
  • [00:17:44] The first step in two steps design
  • [00:18:04] Introducing the new section within the wall
  • [00:20:20] NCC home standards
  • [00:22:19] How to evaluate moulds in your house
  • [00:24:06] The climate zones
  • [00:25:22] Moulds in your wardrobe
  • [00:26:35] The big trend
  • [00:27:45] The minimum NCC standard
  • [00:29:39] The responsibility of a renovator
  • [00:30:53] Balance between what you can afford to do vs. what you’d like to do
  • [00:31:51] How to detect mould without opening the wall
  • [00:33:41] The due diligence training
  • [00:34:47] Make a checklist when you are looking at a property

Why Renovators Should Be Aware Of Mould 

“Mould in buildings is something that we have in only relatively recent times realise is quite a health issue.”

Intro

his episode is sponsored by the Renovation Bootcamp. It’s the renovation fast track for replacing your income now or at retirement. It’s our core training and the prerequisite for our Wonder Women programme. It’s the perfect mix of online and live training. There are eight modules delivered online that you can complete at your own pace. Alongside that, we run eight live zoom tutorials where you can connect with me and our resident experts to help you to apply the training to your personal circumstances. It includes our signature system, the one that we use to produce an average of 100,000 profit from cosmetic plus renovations, plus a repertoire of strategies to make sure that you can progress regardless of what’s happening in the market. If you’d like to know more, go to www.theschoolofrenovating.com/bootcamp.

Bernadette Janson: Hello everyone and welcome back to She Renovates. Today we’ve got a topic that’s not so pretty, but for renovators, it’s very important and that is mould.

I first became aware of the issues that mould causes with health, when I started listening to the Bulletproof podcast, I think it’s become a little bit more mainstream now. People are much more aware of the issues with mould in homes and buildings. And I’ve invited an expert to talk today. We have Andrew Savage of the Building and Design in New South Wales. We’ve got that right Andrew?

Andrew Savage: Business Development Manager for Architecture and Design, New South Wales.

Bernadette Janson: There we go.

Andrew Savage: And it’s Savage.

Bernadette Janson: Oh!

Andrew Savage: That’s okay. I’m very happy to go with Savage. It sounds a lot more up-market, but it’s Irish, not French.

Bernadette Janson: Oh, okay, well, that was a bad move, never mind that. Before we get into it, Andrew, firstly, welcome!

Andrew Savage: Thank you.

Bernadette Janson: I was just wondering whether you’d like to share a little bit about what you do.

Andrew Savage: Thank you, Bernadette. My role is business development manager, architectural design is really with Weathertex. We manufacture Australian reconstituted hardwood products, which are very environmentally friendly, I should say, very, very small carbon footprint, actually, carbon negative footprint. My role is to educate architects, building designers around our product range. We also do continuing professional development or CPD sessions, one of which is all about addressing condensation and mould in stud wall construction. As you say, mould in buildings is something that we have in only relatively recent times realised is quite a health issue.

I remember growing up in the house that we had built in the 1960s. That place had as many houses did in those days mouldy bathroom ceilings weren’t unusual. These days it is a bit more unusual to see mould growing. Also, we didn’t know in those days that it was unhealthy.

Bernadette Janson: Yeah. I have to say that my level of understanding of the extent of the mould problem in buildings is really limited to what we find in reno projects. Generally the bathrooms are nearly always mouldy. Often we’re doing one project at the moment where we must have poor ventilation because the bedrooms have developed mould around the ceiling. And as I said, I know from listening to a podcast that that does create serious health problems. So is it being viewed more as a form of contamination?

Andrew Savage: Well, there’s different causes for mould and then there are different areas in which the mould can occur. So the obvious mould that we see in steamy bathrooms that are poorly ventilated or bedrooms where we may be less inclined to open our windows and allow fresh air into a bedroom, because depending on how you sleep, a lot of people do like to sleep with the windows and doors closed to keep it quieter and so on. Get up, get going to the day and forget about opening up the windows to get fresh air. So it’s generally caused by surface mould is generally caused by poor ventilation.

Then we have other mould issues which we call interstitial mould. Interstitial mould means that the mould is growing inside somewhere where we can’t see it. This is the basis for one of the workshops that I run addressing condensation, mould and stud well construction. What it talks about is the cause of mould actually getting inside the stud walls. So, as most of your listeners will know, lightweight construction generally consists of a stud frame and you’ll have plasterboard on the inside, you’ll have some form of cladding on the outside. And in years gone by, these walls will be ventilated. Getting back to the house I grew up in that was built in the 60s, it had all sorts of vents actually in the walls allowing air to circulate through the cavities.

Now, what happened about 20 years ago is we decided to make our homes a lot more thermally efficient so that they required less heating and cooling depending on the time of year. And as a result, we blocked up all these vents so we didn’t put them in new homes in the first place, and we stuffed all of the walls full of generally fibreglass insulation and so there lies the problem. We no longer have air circulating inside the cavities and as a result, condensation gets inside the walls, interestingly, through the plasterboard, because plasterboard or gyp rock is the common brand that is quite permeable to vapour.

This generally occurs at its worst in winter where we’ve got cold weather outside and we’ve got artificial heating inside, people who are inside breathing and as they breathe, they’re exhaling or inhaling oxygen and exhaling moist carbon dioxide, plus a number of other gases. This moist air that we’re exhaling plus heating devices can also create moisture vapour in the air, especially gas heaters that are on flude. And if there’s no way for the vapour to escape either through an open window or an open door or underneath a crack in the door or whatever, what tends to happen is it actually pushes through the plasterboard.

Then instead of it hitting an air gap inside the wall cavity, it gets caught up in all the tiny little fibres of the fibreglass insulation. We also have the issue of the temperature change because inside the wall, the temperature is lower. And so when we have warmer moisture laden air or vapour pushing through the plasterboard, it then hits the fibreglass’ fibres where it cools down. The act of cooling down causes the condensation, i.e. the vapour of gas condensing from a gas to a liquid and making the insulation wet and so therein lies the problem.

It’s blocking off the vents in the wall. It’s putting in insulation and reducing air circulation within these wall cavities and then not having a way for the moisture to escape. Over a long winter where this is building up on a day by day basis. I’m told that some of the insulation can be so wet from condensation that the bats are actually bowing in the middle from the whites of the moisture trapped in there.

This is a big issue. In New Zealand, they discovered this probably about 10 years ago. The big difference in New Zealand compared to Australia is they have, generally speaking, compared to most of Australia, colder, longer winters than we do. So they do a lot more heating than we do. They also have a lot more timber clad stock of homes than we do because of their seismic conditions. And lightweight clad buildings can rock and roll with a bit of an earthquake, whereas brick veneer tends to crack and fall down. So they had the perfect conditions for this.

When they started opening up their walls and finding all this mouldy insulation inside, they thought “There must be a leak in here.” And then after further research, because I decided to call it leaky building syndrome at first and now because there so many buildings that were affected by it, further research showed that it wasn’t actually a leak but the issue that I described. Condensation getting trapped inside the wall, cavities not able to escape, not able to dry out and eventually going mouldy. So this is a big issue. And as we all know now, probably since the 1980s, which is fairly recent, mould spores are very bad for our lungs. If you’re a very young person or a very old person or you have a pre-existing condition, it can lead to pneumonia and all sorts of complications. So we want to make sure that we get mould away from our homes and buildings.

Bernadette Janson: So with this interstitial mould problem, is there normally any evidence of it outside, like on the face of the wall? Is it common for the wall to look mouldy?

Andrew Savage: Well, no, it’s not, and this is the problem. When we talk about my bathroom in north western Sydney in the 60s and 70s before dad put the mistral exhaust fan into that 1973, you could see that mould and you could hopefully try and deal with it. Because the reason why we had mouldy bathroom ceilings, especially in winter, you’re having a hot shower, the steam rises from the shower, it hits the cooler plasterboard ceiling. And because we have a temperature change, we get condensation and the temperature at which the steam vapour can then. This is from a gas to a liquid, it’s called the dew point. So that’s what we end up with some droplets forming on the ceiling and then, of course, left long enough, generally over the winter months, it eventually becomes mouldy. If you get to it straight away, you can clean it off but, unfortunately, once mould takes a hold inside the plasterboard, it’s very hard to get rid of it.

I remember dad wallpapered the bathroom ceiling, but within a few couple of years the mould started coming through the wallpaper anyway. The stuff you can’t see when it’s inside the wall, Bernadette often you don’t know it’s there. If you did know it was there, it’s going to be pretty nasty if it’s actually coming from the inside out. It may not be, though, if you’re seeing on the inside of the wall, chances are you just need to open up the windows and doors in that room, let the air circulate through, clean the mould off, let it dry out really well, and chances are it’s just surface mould happening on the inside of the wall anyway. I think if you had mould coming through from the cavities to the plasterboard, you’d really be looking at having to rely on just about the whole place. It is an issue.

Bernadette Janson: Yeah. So, well, we have a student who actually her home was flooded and it became so wet that the whole house just went mouldy and in the end it had to be demolished. She became very sick as a result of it. And my understanding is the illnesses, it can be responsible for some new illnesses and can be quite devastating long term.

Andrew Savage: It’s like a parasite. I mean, you don’t want them in your body, these little these little things. I don’t really have a lot of information about the medical associations. But as I mentioned earlier, it really wasn’t until the 80s that we realised how dangerous mould was, because, as I say, I remember as a kid, it wasn’t just our bathroom. You go to your neighbour’s houses and they don’t have mouldy bathroom ceilings too. It was just the way it was until we got mechanical ventilation.

The good thing is when we get back to what the area that I sort of, I guess, become slightly specialist in, which is interstitial mould, mould growing inside like white stud wall systems. And this is irrespective of the type of plastic board or cladding, the brand of plasterboard, the brand of cladding you have, it can affect any type of light stud wall construction. Not so much, britfiny, because britfiny already has a cavity built into it so you get air circulation happening. But there is a reasonably easy fix to address this problem.

Normally when I do the CPD presentation, we obviously show images and sectional diagrams and so on, but I’ll try to describe to you now that we understand where the mould is coming from. So we’ve got vapour occurring inside the room. It’s pushing outwards because any sort of pressure inside a vessel is just by physics, the pure nature of physics it’s going to want to get out. We think about blowing up a balloon. If we blow up a balloon and then let go of the end, the air inside the balloon of high pressure will come out until we get pressure equalisation between the inside of the balloon and the outside atmosphere. The same thing goes for room, so if we have people inside a room breathing out water vapour, we had the heater, especially gas heaters producing water vapour. The vapour pressure will be higher inside that vessel or room, and it’s going to try and force its way out whichever way it can. Part of it at least will be going through the plasterboard and getting trapped in the insulation, like I said. So that’s the problem. Then it condenses when we have that change in temperature between the warm room and the colder cavities.

So what we need to do is as a two step process, because there’s a third thing happening here, which I hadn’t mentioned yet, and that is you’re probably familiar, Bernadette, with stocking building wraps.

Bernadette Janson: I was wondering about that.

Andrew Savage: Yeah. Well, this is the other issue that we need to address, because building stockings are really designed to be a secondary barrier against rain getting into the cavity wall system. Should there be any breach of the cladding or breach of a flushing around a window or something like that if water does make its way in and the building could be perfectly built, but if you have a very high pressure storm event, you’re going to get water pressured into the facade of a house. There’s always going to be very extreme weather events where moisture is actually getting in. And so that socking is designed, if you like, a bit like a clad wrap around the building. And that’s the problem, to stop the moisture coming in. If it gets past, the cladding will pass any flashings around windows and doors, we don’t want it getting into the cavity. It’ll trickle down the face of the socking and just dry away.

The problem with that is when we’re wrapping our buildings, so let’s just talk about what a section of the wall would be. We basically have a stud frame, timber frame, or it could be a steel frame, and then on the inside of that, we have our plasterboard on the inside in between the studs, we have fiberglass insulation, generally speaking, on the outside of the studs wrapped around the building is the stocking or building wrap? You know, it’s made out of different materials. Generally speaking, it’s a flexible sort of fabric type material. Sometimes it can be made out of paper and there’s different materials that have evolved over the years. And then we have our cladding, which is generally fixed through the socket into the studs, so that socking is trapping the moisture in.

The first thing that we need to do to address this problem is to introduce a different type of socking, which is called a vapour permeable membrane or VPA. These relatively new types of sucking, at least to the Australian market. They’ve been on the market in Europe and America for many, many years. But this issue is, I guess, more recent down here, because colder jurisdictions have been making their homes more thermally efficient for a much longer period of time than we have down here in Australia than New Zealand. So, they have a bit more experience with this. And so these stockings have been on the market over there for 30, 40 years.

There’s different types of products, the types of brands that you might look out for are CSR, Bradford Enviroseal, which is a type of socking or building wrap which will stop moisture coming in from the outside that will still allow vapour to pass through from the inside. They’re quite clever how they do this. There is another product called watergate by a company called Therma Kraft. We have quite a strong relationship with Therma Kraft, and they have fabulous products that are very good people to deal with. That’s actually a New Zealand brand but they are manufacturing here in Australia is also Tyvek, there’s a proctor wrap there’s a company called Ametalin that make a product as well. All of these products are called vapour permeable membranes and what’s called a class full membrane. And I’m just going to try and remember the Australian standard. I did have it in my head this morning, but my memory for numbers isn’t what it used to be. But anyway, I’ll give you that and I’ll give you that for the notes as well, that, yeah, it’s a classical membrane.

According to this particular standard, it’s a first step in our two step design solution to overcome the problem. And so what these vapour permeable membranes do is they stop rainwater coming from the outside, still allow vapour to pass through from the inside. And it’s how they’ve woven these fabrics is how they achieve it.

The next step that we need to do, and it’s very simple, is we need to introduce a new section within the wall, a new area, if you like, which is outside of the vapour permeable membrane, but behind the cladding. In order to do that, we just need to add and only need to be nine or 10 millimetres deep, but a cavity bed. What this does is it moves the coldest part of the system to the outside of the vapour permeable membrane.

So as the vapour pressure gets pushed through the plasterboard, the insulation is also very easy for vapour to pass through because of the way it’s woven together as thousands of little fibres with lots of air in between. And it then goes through the vapour permeable membrane, which is also very permeable to vapour. It hits the cavity, which now is the coldest part of the system. And that cavity, as I said, is about nine or 10 millimetres deep. The water condenses from a vapour or a gas to a liquid and then runs down the outside face of the membrane or the inside face of the cladding and then drains out the cavity slot at the bottom. Problem solved.

You’ve really only added about nine to 10 millimetres to the thickness of your walls, which is important. We don’t want to make the walls too thick because real estate’s expensive. The custom of the permeable membrane over standard type of socking is not that much more in terms of the overall cost of a project. It’s quite a simple fix. And there’s a number of companies that you can talk to about this level of detailing CSR, Wheathertex, other fibre cement cladding companies, although Wheathertex is Isn’t fibre cement, Wheathertex reconstituted Australian hardwood, therefore much better for the environment that we can talk to about it and also the people that make the vapour permeable membrane. So Therma Kraft, CSR, Bradford, Ametalin, Proctor Wrap and so on.

So that, I guess, is in a nutshell what the solution is. As I said earlier, if anyone is kind of unsure about it, you can contact any cladding manufacturer pretty much. Please always reach out to Wheathertex and any insulation manufacturer and they’ll be able to give you details on how to design these walls.

Bernadette: I’ve got a few questions. So I’m thinking about this in relation to our renovators. So I’m guessing it probably relates to historical homes predominantly?

Andrew Savage: Yeah, well, it’s kind of related mainly to homes that have been built in the last 20 years because prior to that, like up until about 2000, the NCC such BCA standards didn’t require us to make our homes extremely efficient, as they have done since about 1999. I think it was around 1999-2000 that they started introducing in New South Wales. The basic system in other jurisdictions that matters and that’s all about window performance, wall performance, roof performance, that type of thing, the thermal utility. So it’s really only affecting houses that were built in the last sort of twenty, twenty five years.

Bernadette Janson: And the other thing is, I’m assuming that to retrofit this is a major exercise?

Andrew Savage: Well, it sort of is. And it’s probably not something that I would suggest you would tackle unless there was evidence of an issue. And look, let’s face it, in a place like Sydney, we don’t really have long cold winters. If we do, we might have heating for maybe three months of the year, but it’s not like perhaps Tasmania or parts of Victoria where they have maybe heating for six months, seven months of the year. And it’s going to be more of an issue in those jurisdictions because of their climate.

So I would suggest that if we’re doing any renovations, well, anywhere where it’s a bit warmer than, say, Victoria and the southern regions and incidentally, we’ll talk about climate zones in a moment because they will affect what we need to do. But let’s say sort of the Victorian border north, it’s probably not going to be as much of an issue as it is in the colder areas. If you did come across this, if you were renovating a house and you pulled off the cladding or you pulled off plasterboard and you found mould in the walls, I’d be looking for the cause.

The first thing I’d be looking for is, is there a leak in the wall? Because that’s obviously the first obvious cause. If you can’t find any evidence of water tracking and generally if there is a water leak, you will see tracks of water somewhere, then you go, “OK, well, maybe this is an issue,” like we’ve spoken about today. Then you would get some expert advice probably from the cladding manufacturer or if you’re not looking at replacing the cladding, your plasterboard manufacturer and just see what you may or may not be able to do.

If you do need to change the socking, you’ll have to take the cladding off. That doesn’t necessarily mean that you can’t reduce the cladding if you’re careful in taking it off, you can reuse it and fill the holes. Sometimes it’s just more cost effective to replace it. As much as I hate to say that it all comes down to the cost of the labour associated with being very careful, taking it off and putting it back on again versus the cost of buying new material. But we also should take into account the environmental cost of buying new material if you don’t have to. That’s something else to keep in mind. I think it’s something where you need to just weigh up each project on a project by project basis.

Around climate zones, the NCC changed last year from the 1st of May this year, they’ve adopted at least one part of our two step design solution, and that is the vapour permeable membrane. They have said that if you’re in climate zone six, seven and eight, which is a cooler climate zones. So climate science six includes places like Hornsby, Campbelltown, Baulkham Hills, anywhere, that’s about 30 KS from the coast where you do get cooler winters. I was in Hornsby as a kid and it gets pretty cold up there in winter by Sydney standards, that’s climate science six.

So if you’re building a new home up there or doing major renovations and you need to use socking, you would have to use a four permeable membrane. But it doesn’t request in the NCC for the cavity unless you’re in Tasmania.

In Tasmania, they’re local BCI requests cavity as well as the socking. But in most of the rest of Australia, they haven’t adopted the cavity and we recommend you do both. Pretty much for any climate zone apart from the tropics, which is climate zone one.

Bernadette Janson: Isn’t strange because in the tropics everything goes mouldy.

Andrew Savage: Yeah, well, it’s a different problem up there. I’ve stayed in plenty of hotels and resorts in places like Port Douglas where they just keep the air conditioning on forever. And I don’t think I have a service or claim the filters or not as much as they need to. And you walk into the room and often you get hit with that mould smell. And generally what I do when I arrive in rooms that are like that is I can’t get another room which is mouldy, I just turn off the air conditioner and open up the whole place and let the air sort of circulate while we’re out swimming or whatever, and then come back and turn it all on. And I’ve even been known to ask for a vacuum cleaner so I could clean the air conditioner filter. But that’s just me. I don’t like the mouldy smell.

Bernadette Janson: It is a problem and like I mentioned before, it does have serious health implications. We lived a couple of years in Darwin and everyone had these things that capture moisture and their wardrobe, otherwise all your shoes went mouldy. It’s amazing that it’s not a problem there. But I guess they don’t have that change in temperature from inside out.

Andrew Savage: Well, I think the mould in those areas is because the problem’s almost inverted to a point. It’s hot outside pretty much all the time and it’s air conditioned inside pretty much all the time. If your air conditioner is working properly and it’s taking the moisture out of the air, it shouldn’t be a problem. But when you get areas like wardrobe’s where you don’t have a lot of air circulating, yeah, you do get mould issues. And I’ve had mould issues in poorly ventilated wardrobes in Sydney in the past as well. You can get those things that extract the moisture out of the air and you’ve got to empty out the bottom of them because the water actually collects them. You can even get a wardrobe, I think they’re called wardrobe dehumidifiers and they’re like they’re almost like a heater that runs in the wardrobe and keeps the air dry. But it’s all about the circulation of air and keeping air moving.

And another big trend, what’s not a big trend yet in Australia, but it’s becoming that way in Europe. And you’ve probably heard of passive house design. Passive homes are ones which are designed well so that they don’t need heating and cooling and they generally have an air recirculation system and they design the air recirculation system. So it pretty much gets to every part of the home. And I don’t know how often it changes the air so many times an hour. It still maintains the same temperatures in the home due to the use of thermal mass and other techniques.

So I think that we’re learning more and more about this. And I think that the average Australian home, as it’s built, say, by most project builders, is there’s a lot of room for improvement in terms of not needing to air conditioners much and a bit more thermal consideration aspect on the block and so on. We are getting better, but we still have a long way to come. And I think that air circulation and the whole passive house concept is actually going to become more and more popular because it’s also about having a healthy home and a healthy environment to live.

Bernadette Janson: I absolutely agree. I think it’s like anything they built through price.

Andrew Savage: The minimum NCC standard is the minimum standard. We would like to think that we can go beyond that. And I know that some project builders will give you options to upgrade insulation and do other things. And I know that the aspect of the home is taking into account a lot more now with the best system in New South Wales and and Nettos. But we still got a way to go, I think, before we’re starting to build homes as efficiently as they can be.

Bernadette: It doesn’t necessarily need to cost an arm and a leg extra to do that either.

I know a lot of what we’ve talked about today probably relates more to people with their own homes. But I’m just wondering as because a lot of our audience are renovators for profit, what our responsibility is? You mentioned that the NCC and for those who don’t know, that’s the new equivalent to the building code of Australia. It’s called the National Construction Code. So you’re saying that for the permeable membrane, that’s covered most areas, including some of Sydney, but particularly the coldest the states, not the tropics, and that only in Tasmania has some of the councils adopted the cavity measures to improve or reduce the moisture?

Andrew Savage Janson: Actually, the Tasmanian BCA, because each state has its own BCA and the national code is in the national construction code. The Tasmanian BCA requires both a class for vapour permeable membrane and a cavity, whereas most other jurisdictions and only in climate zones six, seven and eight, the cooler areas, which includes parts of Sydney, require only divided the permeable membrane. But like what I said before, that’s the minimum standard. I think that for the cost of cavity battens, which is so low compared to the whole cost of the home, we’re talking about a drop in the bucket. You just mean that the house is a lot more user friendly, safer and cleaner to live in.

Bernadette Janson: So I’m just wondering, as a renovator, if we open a wall up and we find that it has a moisture problem and that problem is not due to a leak, it’s due to the interstitial mould issue. What’s our responsibility?

Andrew Savage: I think the first responsibility is to try and get the mould out and clean it up. And the other thing too, Bernadette is quite often people are renovating just one part of a house. Now, they’re not necessarily pulling the cladding or belongings off all the walls. So if it’s in one part of the house, you can possibly presume that it’s in other parts of the house as well.

So it comes down to what you are prepared to do versus what’s in the budget to repair it versus so many other factors which can make the whole thing very subjective. So, I think it would be nice to think that people would try and do the right thing, but where do you draw the line? If you’re only planning on pulling off the back wall because you’re extending out the back and then there’s the front and side walls as well, do you pull the cutting of those and put a new membrane on? I think probably the best thing to do would be to get some advice. And there are other companies out there.

There’s another company I’ll mention their name, they are called Pro Clima, and they specialise in these types of situations in prevention of condensation in wall and root systems and also potentially addressing them. There may be other treatments or other ways that it could be addressed. If you are adding to a home, you would obviously need to, if you’re in climate zone six. The minimum requirement would be to use a possible chemical membrane membranous the socking I would probably add to that add cavity battens as well. They’re not really going to cost you that much more and it will mean that what you’ve added to the home is going to be best practised from the condensation point of view.

But it’s a pretty hard question to answer because if you’re renovating a home to make a profit, it needs to be a balance between what you can afford to do versus what you’d like to do versus issues that you’re going to come across in your renovation.

Bernadette Janson: It does become a bit of a mould dilemma. We have a few things that we say we spend the money on regardless of whether we get it back, because there are things like putting in a code of practise, before it was compulsory. Now it’s not but we did it anyhow because we figured if it saved a life it was worth spending the money. But there is that balancing act, and I’m thinking that is it possible to detect the problem without opening the wall up?

Andrew Savage: It sure is. You can get moisture metres. I’ve bought and sold and renovated over the years myself, and I always, always get a property inspection.

Bernadette Janson: Yeah.

Andrew Savage: I just always do it. And I’ve put off a couple of properties in the past. One was a brand new apartment actually. When they put the moisturiser on the wall, I said, “Well, the walls are wet,” there’s plasterboard over something, but there’s a lot of moisture with it being detected.

The only caveat is that if you use a moisture metre in the middle of summer when everything’s dried out to a point it may not highlight the problem. But if there’s mould in there and the moulds alive and it’s active, that is going to be a certain amount of moisture. So you could put a moisture metre on the wall and get a property inspection.

You could make sure that you buy properties that are built before a certain time as well. Ones that were built, say, 20 years ago, are definitely going to have insulation in the wall if the brick veneer is all white clad. So maybe you look at buying properties that don’t have insulation in the wall. They’re not going to be as thermally efficient, but at least you might not have this problem.

When you are doing renovations and you are adding to a building, you must go the minimum standard. As you mentioned before, with the roof leakage, which is things like smoke detectors. The other thing, too, that a lot of people don’t realise when they’re buying older homes, especially very old homes, is rewiring is a big issue. And it can cost you 20 grand to rewire a house.

Bernadette Janson: Yes, that’s why we’ve got a whole training on that. We’ve been put on the due diligence and I think 20 year old homes are great renovation projects, because they’re pretty easy to get up to to look great, and how they’re built using modern building standards. But this is a problem that I had not considered before. I’m thinking that it probably does need to become part of the due diligence process, because if you can determine that it has the problem before you buy it, I do a lot of apartments, so they are all mostly solid bricks or something. But for anyone doing houses, that is something that we don’t want to be faced with the mould dilemma.

Andrew Savage: I think, just be aware that it could be an issue. As we said before, it depends where you are. And the further north you go from, say, Wollongong upwards and even maybe sort of south coast to a point as well, like around Huskisson sort of homes, what do you call that area? That whole sort of area down towards the Georgian space? And that’s probably okay, too. It’s when you’re in the colder places jurisdiction’s where it’s going to become more of an issue.

I wouldn’t get too concerned about it but, if you get your property inspection mentioned to the inspector, “It’s a lightweight clad building, it’s probably got wall insulation. I doubt very much that I’ve used a breathable stocking or membrane and cavity battens, so can you please just make sure that there’s no high levels of moisture in the walls?” And they should test for that anyway but just mention when you’re getting the inspection done and it is something that affects, as we said, houses that haven’t been designed to address the problem that have been built in the last twenty years. Having said that, I know of houses that were built in the1980s that had insulation put in the walls because remember, that NCC’s minimum standard. And a lot of people out there do better than the minimum standard, so I remember one best mate, they had their house renovated for the first story addition on and it was all light white clad in with a takes, funnily enough, and this is going back to 1980.

They put insulation in all of their walls because they knew that it would make the house perform better thermally, even though they didn’t have to back in those days. So just be aware, it’s just something else that you need to maybe put on your checklist when you are looking at a property. And if you do decide to make an offer, please always make it subject to a property inspection and mention to your inspector a lightweight clad check for moisture in the walls, and want to make sure that there’s no sort of trapped condensation such as mould problems. And then if you do that diligence and you still find issues, well, then you just have to address them and do the best you can to fix the problem. Because, I mean, I don’t know about you, but I want to make sure that if I’m renovating a project, I’m making it better. If there’s an issue in this area that we address it so that we’re not making it somebody else’s problem.

Bernadette Janson: Exactly. Well, listen, we’ve got to wrap up here because I think we’ve addressed the topic adequately for now. Thank you for making us aware of this. It’s certainly not something that I had given a lot of thought to up to this point, and I appreciate your time. Now, what we will do is include all the details, images and all the contacts that you have shared in this episode, in the show notes. For anyone that’s wanting more information, I’ll also include Andrew Savage’s contact details. Is that OK with you, Andrew?

Andrew Savage: Yeah, that’s fine. No problem at all. Maybe include my email address and if people want to drop me a line, they’re very happy, very happy to respond to them.

Bernadette Janson: Yeah. So thanks again!

Andrew Savage: It’s a pleasure. Thank you for having me. I really enjoyed it.

Bernadette Janson: No worries.

So that’s it for today. Now, if you have enjoyed this episode and got value out of it, we’d really love to hear from you. So if you could just head over to iTunes and leave us a review, we would love that. We read them all and it gives us the wind under our wings to keep going. So thanks and see you next week!

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