Episode 07: How to keep your house warm and your bills low

There is no denying that it gets progressively colder outside – and unfortunately for many homeowners, inside as well. With dropping temperatures, the need to improve a home’s thermal performance and insulation is becoming bigger and bigger. Which is why we decided to bring our trusted builder David from Ecowise Homes back on the pod and grill him about what options there are to winter-proof a home – with small budgets and little knowledge in mind.

I am sure there are more than a few valuable tips in this episode that you can use to get through winter in a more comfortable and affordable way.

One more note, as Anthony has both design as well as building knowledge, it simply made sense to have him take the lead with the questions in this episode.

Episode Transcript

Sandra Redlich  00:05

David, thanks again for joining us a second time around. This is the first time we had a guest on for the second time. But that’s just shows how much we enjoyed talking to you. Today is a very special episode, a seasonal special, so to speak. Winter is approaching and it’s getting colder outside and I’m pretty sure that a lot of our listeners are trying to improve the performance of their home. And you are the perfect person to talk to about that and nerd out about what people can do to get through winter in a more comfortable way. So let’s get right into it. What can people do to improve the performance of their home?


David Millard  01:51

No worries Sandra, thanks for having me. Great to be back again, feels like a while since we’ve chatted. But yeah, so I do have some great tips on that today for all the listeners on how to improve their home for the winter coming. I’m sure everyone’s starting to feel it get a little bit cooler as the days are getting shorter and also colder. So you know, the first tip today is make sure you listen to this podcast right through the end because we do have those really good tips on that. And I also think it’s not so much a tip, it’s more advice of a book to go purchase. And it’s the Your home Australia book. I think they’re up to the sixth edition. I think it’s about 600 pages of just great knowledge on you know, how to improve your house performance and great information there. So that’s probably the most important tip, I think at the end of the day is go ahead and look at that. And yeah, I know you’re familiar with it Anthony, what do you think of that?


Anthony Jenkin  02:51

That is really solid advice. I consider it to be the Holy Bible of our industry. And I recommend it to everyone listening. Particularly in the new addition, it even includes airtightness, and it touches on passive house as well. So yeah, definitely look that up, you’ll be able to search your home and Google and find that very easily.


David Millard  03:11

I suppose for a start, I’ll just start off with some tips that I think would be suitable just for like a DIY, it probably would depend on your level, obviously. You may be very amateur at your DIY or you could be very capable too. But I think let’s look at it from like an air leakage perspective from a start. As far as DIY tips and to start off with I think, you know, you could go around and do lots of caulking or silicone and you know if you caulking paint over it if need be, but around your home, you find all sorts of different cracks and you know, there’s connections between your timber floorboards maybe and your skirting boards where you will find air leaking through. So with that, I’ll just recommend you run a bead of silicone right around it. You know, that’s where you have your plaster board, you’re skirting, sometimes crack there and you do have, you know, leaks there. Between your corners and your plaster board. You can protect potential leaks there. And the other spot would be your timber floorboards. I’m sorry, if you have a house on timber stumps, or sorry just stumps, timber subfloor. We generally find that they’re so much more leaky than a house on a concrete slab. So, you know, it could be a matter of getting some timber colored caulk and sealing up any gaps that you do have in your timber floor. But as you can see, there’s a bit of a common trend happening that it may seem so small that you’ve got all these hairline cracks or one millimeter cracks in your old house, but over your whole house, all those cracks really do add up, you know, to create quite a leaky home.


Anthony Jenkin  05:10

So when we test a home, or for those who aren’t familiar with Outlier Research, you know, we offer blower door testing. So when we’re testing, we’re able to determine where all those little gaps and leaks are occurring. And then we provide advice on that. So one of the big things that we see, specifically in older homes, the vents in ceilings or in walls, and you know, there’s a lot of air leakage occurring through those. Would you have any advice, David, on how people can best tackle those? Those vents?


David Millard  05:40

Yeah, definitely, the wall vents are huge. And like you do, obviously seeing those older homes. You know, all rooms are probably one or two vents up in the top corners of your home. Look, it’s depending on how far you want to go. I’ve actually been into people’s homes, that they are looking to do a renovation extension. And they’d like literally going around with about six rolls of masking tape, and just covered over everything. So I walked in, I was like, You guys preparing to paint? No no, we are just so cold that we just had to seal everything up. So yeah, I wouldn’t recommend putting masking tape over everything, you want to do a much more professional job than that. But with those vents, it’s probably just a matter of getting a tradesman, like a plasterer, in to, you know, just crack off the old plaster vents. And you know, just put a sheet of plaster over and trowel straight over them. And then obviously sand it up and repaint your wall.


Anthony Jenkin  06:34

So for wall vents, that definitely would be the most logical approach. However, for the vents that are in the ceiling, would it be reasonable to be able to put something on the top side of the plaster board to cover those over?


David Millard  06:45

Yeah, I think so. For sure. It all depends on what stage you’re at with your home. I think how much of a quality job you want to do honestly. If you’re really house proud, you just did a renovation five years ago, and it’s not planned to do any renovation for a while, but you may have missed some, you know, air leakage or performance, things that you obviously want to do a professional job and get it done, right. But if you do know that you plan to do a renovation in a couple years time, then you don’t really care at the current stage, what your home looks like, it’s just a matter of sealing them up and getting the best performance out of them. So yeah, it’s depends on the situation. And I think how far you want to go with them Anthony.


Anthony Jenkin  07:30

That’s great. And I suppose when we test, one of the things that we also identify pretty quickly is exhaust fans that don’t have draft stoppers at all on them, or in line. So what would the best approach be to rectifying exhaust fans that go straight to a roof cavity or directly to outside air?


David Millard  07:51

Yep. So obviously, I’d recommend getting a licensed electrician around to put draft stoppers at the top of them. It’s just a baffle that goes on top, and then when the fan’s switched on, the pressure of the fan lifts the flap up. And then when the fan stops, it just flapped back down to prevent drafts not flying through. Another one too not to forget is the rangehoods. You’ll need one of them on them too. So if you don’t have one of them on your rangehood, again, it’s just getting draft straight out of your house. A couple of other key ones, Anthony, that I think too, is external doors and windows, I’d recommend you know, going around your home – and this is a DIY task that you can do – is get foam seals, you can pick them up from Bunnings or Mitre 10 and that and install them on all your external doors and windows just to prevent those drafts and that going through. And I think another big one is too, that often, I do see that they’ve been installed on like a timber door for example. And when it was installed, it was installed correctly that you know, touching top and bottom in the middle. But over time, that door may have bowed. And you do see the rubber seal is touching in the center. But as the door bows down the bottom and top, there’s actually a gap there. So I would recommend to you know, put another piece of foam on it to make sure it’s sealed up.


Anthony Jenkin  09:20

So that sounds like something you could probably just check annually. Check the condition of your seals around your external doors and windows?


David Millard  09:27

Definitely yeah, absolutely. Another thing is doggy doors. Often people have department locks and that sort of thing, like mail delivery slots and that sort of stuff. They’re all just little minor spots where things can actually leak and that sort of thing. So yeah, I’m not too sure what’s available to retrofit doggy doors and mailing slots, but I’m sure there’s much more efficient products out there that you know, you could perhaps look to purchase that will be sealed up a bit better than your old ones.


Anthony Jenkin  09:57

Are there any other things that come to mind David that you could mention, anywhere that you would look to find air leakage, drafts or leaks?


David Millard  10:05

Yep. So I’ll do a few more for the DIY sort of tips. And another good one I find is old chimneys. You know, especially with old Victorian homes, you know, there’s often the forefront rooms and pretty much maybe every room has an old chimney in there. In an old fireplace or whatever, you can just cut a piece of timber in there neatly and seal it in, you know, prevent the drafts through there. I’ve even heard of actually people shoving balloons in the chimney to pop that off. That’s probably a short term thing when they pop, but yeah, I’m sure that would work. Another one is the evaporative air conditioners, they are just like a vent straight out your house in winter. But, you know, obviously, you could go install a new air conditioner and get rid of your evaporative. But even just a quick solution is, and my mother’s done this 30, 40 years ago, whenever we had an evaporative air conditioner on our old farmhouse, she just cut sheets of vinyl in over the vents on the ceiling and just slot that in on top of the grills. And that way, you know, you’re still going to get a little bit of leakage but definitely minimize that heaps. So another one I find is the old toilets. They often have where the window is like a vent. Like it’s not all glass, the window, it’s part vented. So that was the you know, the old days, they want to get rid of the smells and that, but that’s a spot that just leaks all the time. So to do that, you can obviously get a new piece of glass installed, or even just cut a piece of perspex plastic over it to stop any leakage.


Anthony Jenkin  12:00

I’m really glad you mentioned that one. That is a legitimate hole in your wall that can be fairly significant at times. You also find them in older bathrooms as well as toilets.


David Millard  12:11

Yeah, so there’s probably my main sort of DIY tips that I’ve come up with. But yeah, obviously, there’s some that you know, you may have to get a tradesman in to do or a handyman. But yeah, that’s something to get you thinking. And you can go around, check your home and find out where they are.


Anthony Jenkin  12:33

Resolving air leakage, in my opinion, is the best money for value solution to improving efficiency and comfort of your home. And as you say, like a lot of this could be as simple as getting some silicone from the local hardware shop. And just going around and sealing up those gaps that you’ve identified. It all adds up as you say, it doesn’t look like much collectively, this has a potentially a large hole in your wall, like a door or window being open. And it’s letting heat pass out in the cold months. Just by getting around with some silicone, you can make a huge difference.


David Millard  13:08

Yeah, it just goes back to what I call the one percenters and it just all adds up. And it’s the same when we do new construction. We’re always focused on that detailing and it may sound minute when we’re talking about new home construction of you know, making sure that the wrap’s all super tight, so we don’t get little wrinkles when we’re taping. But it just adds up, all the cracks, it just, you know, it may sound minor but it definitely adds up. So yeah, especially when air leakage equates to 15 to 25% of your heat loss in in winter and that sort of thing. So it’s a very, very cost effective way to get on top of things Anthony.


Anthony Jenkin  13:47

Absolutely, it’s up to a 25% improvement right there. I suppose the next thing to touch on is insulation. It probably comes a little bit more of a higher price point to achiev this for walls, but those who have access to their sub floor, and most will have access to their ceilings, what would be the best approach to insulating a home?


David Millard  14:11

People have an opinion I think that they need to go zero to hero all of a sudden. It’s something that can be done very gradually to improve the performance of your home, whether that’s air sealing or insulation. So it’s one of those things like every home is different, unique you know, you could have a timber sub floor, you could be on a slab, but say for example you do have a timber sub floor, it’s just a matter of getting under there at some stage and say Oh look we can access right under here or Yeah, it is tight under one corner and just get some insulation bats installed. I think the under floor leakage of your home is 10 to 20%. So obviously, if you can seal it up as best as possible and put insulation there, it’s gonna make a huge difference. And as far as products to install for underfloor insulation, I’d suggest bulk installation batts, which I’ll touch on later, the different types of insulation. Or not all insulation, but the majority of insulations out there and what their pros and cons are. And that I suppose the other one is that you can use on a sub floor is your polystyrene foil board. Yeah, that’s also a good one. But yeah, and then the next one would be like, you know, to improve your ceiling. Your ceiling is going to be your best bang for buck, because you do lose 25 to 35% of your heat loss in winter through your ceiling. So if you were going to start with somewhere, you know, and you can access these ceilings, the best one for your ceiling is probably insulation batts, is your best option. Otherwise, you can go with like a blow-in sort of insulation there. So your two major ones, but just a bit of a disclaimer out there, just be careful putting insulation in your ceiling, you don’t want to be covering over the old halogen downlights. You need to actually have covers around them with them overheating. Now I know we had issues in Australia, going back a few years ago. So it’s probably best to have a licensed electrician come along to just, you know, double check you’re doing the right thing.


Anthony Jenkin  16:39

And just to add to that, LED downlights you’re looking for that will allow you to completely insulate over are ICF rated. So if you want to insulate completely over the downlight, make sure it’s ICF rated. And if not, maybe look for an LED barrier, that’s a cone that goes over the top of that LED light. And then it allows you to insulate right to that cone and over the cone as well.


David Millard  17:03

That’s it. And then as far as insulation, that sort of thing, the next one’s your walls, they’re often the hardest ones to get to. It just depends on what stage your home’s at. So it can be quite expensive to do because obviously you need to access inside your wall to be able to do it. So with the walls, I’d probably recommend to wait, you know, if your home’s at a stage where you do need to rip off the weatherboards, they’re old and deteriorated or wait another couple of years until they’re completely new to be replaced. And then we can look to put insulation back in your wall and even perhaps create your walls to be a bit thicker to get thicker insulation in. Or it could be that you do have good external cladding, but the plaster inside, or whatever lining you do have inside, is starting to lose its quality and that sort of thing. So you could perhaps strip off the internal lining in your walls and insulate there. But once again, with your walls, I’d just be looking to do like a bulk insulation batt with them.


Anthony Jenkin  18:13

So one of the most common places that we don’t see installation being installed, even in new builds, is on the external junctions of the frame where the internal walls link to the external walls or meet the external walls. And those junctions, if the external cladding is going to be removed? Well, that’s great, because then you know that, you know, you’re gonna have access to those junctions. But if it’s going to remain, and let’s say that you’re going to be removing the plaster board, is there anything that anyone can do to insulate those junctions?


David Millard  18:42

Yeah, definitely. So if you’re actually accessing it from the inside, you can, you know, drill holes in your stud, don’t go drilling too big a holes. And you can actually get expander foam and spray it in there. So that way all your junctions and that got some form of, you know, fiber insulation there. It’s not going to be as good as, you know, access from outside and actually putting insulation there. But yeah, it’s definitely going to, you know, get some form of insulation there to improve the performance of it for sure.


Anthony Jenkin  19:14

So just being able to drill through that stud is going to be enough to get the nozzle of the expander foam, I should mentioned use low expansion foam, if you can, is probably you know the preference to get that in there, to insulate those junctions.


David Millard  19:28

I’ve got a list of insulation, different types of insulation here that I’ll go through that, you know, people could consider using for their home. To start off with, there’s like a bulk insulation which is your most costly form insulation. So that can come in a batt form. So it actually suits your stud width or your flooring width for your gaps between your trusses and that. And the other format that comes in is like a loose fill, so they just go right in and that’s often used in ceilings and that. But there’s also different types of material that the insulation comes in, like you can get it out of a glass wool product, you can get it out of a rock wool product, which is like a volcanic rock spun into this wool sort of insulation batt. And you can also get a polyester insulation batt or you can actually get an authentic wool batt. Obviously they are all at different price points and that sort of thing. But you know, they’re all going to be really efficient to put in your home. And then you can start moving into sort of like your polystyrene insulation. There’s the two major ones that I would recommend for this. And that’s the extruded polystyrene, it’s also known as XPS, and expanded polystyrene, which is EPS. So they’re both great insulations when you don’t have much room to insulate in. They’re very thin, but you also get great insulation quality. And the XPS is really good because it’s got a high compression strength, which makes it great to put underneath house slabs when we’re doing new construction. Because it can actually handle the weight of the house on it.


David Millard  19:47

So one of the other things that we often see when we’re doing our inspections using the infrared camera is access hatches into ceiling or roof spaces. So what can people do to insulate that access hatch?


David Millard  21:41

Yeah, so I actually in passed renovations extensions, I would install just a traditional sort of manhole surround, but make sure it’s, you know, well sealed around where it’s going to have plaster butting into it. And also where we have the actual panel that sits on top of the surround, also install foam around that. So you’ve got a good tight seal. Also the manhole access as well sealed, but then obviously, as of yet, it doesn’t perform that well as far as insulation. So what we actually do is install foil board on top of the actual piece of timber that goes on the manhole. So we put two sheets of that on so it does have a good insulation performance as well.


Anthony Jenkin  22:30

You mentioned seals, what product can people use to create that seal that you’re talking about and would they get adhered to the inside of the access hatch?


David Millard  22:42

Yeah, so I’ll seal it to the inside of the surround. And it’s just like a little rubber gasket virtually that just sits on the manhole surround and then just a piece of… We use melamine which is just a piece of 16 mil timber with a vinyl veneer over the top and bottom and that just sits on top of that surround. Another, it’s not that common, but another insulation that you can come across is the cellulose insulation. So a plant fiber insulation which is made up out of newspaper cardboard, cotton straw, saw dust, sometimes hemp or even corn cobs. But yeah, it’s really good insulation, it’s probably not that common, but it is very eco-friendly and sustainable as well, just so all the listeners can be aware of that one too.


Anthony Jenkin  23:35

Is there anything further that listeners could do to improve the thermal comfort of their home through using insulation?


David Millard  23:41

That probably covers off.. Well, actually no, you can seal up some, as far as insulation, depending on the type of heating and cooling you do have, whether you wanted to insulate internal walls of your home. But also personally I’d just be looking to improve the whole outer building envelope of your home and get that to a really good standard and not worry too much about internal walls. But yeah, that probably covers off the majority of the sort of basic insulation tips. I do have a couple other ones that I’d recommend for air sealing. And then I’m like going into some pointers about actually ways to find out leaks in your home.


David Millard  24:30

So I do find, especially in new homes, that there’s a huge gap often behind and up the top of your fridge. So we find that the plasterboard gets installed in your home or if it’s a relatively new home, then the joinery company will come install the joinery, but there’ll be no cornice installed around the way the kitchen goes. So the joinery goes in. And then the plaster comes back later and butts the corners into where the joinery is. So you get left with this cavity at the back of your fridge, that drafts from your fridge all the way out of the back of your joinery out into your roof cavity. So I’d recommend to cut in a piece of ply, plaster board, anything in there or even you can foam seal it, depending on how big the gap is to ensure that that doesn’t leak at all. So yeah, just wanted to mention another relatively big leakage that can come across from that.


Anthony Jenkin  25:41

One more thing that comes to mind. So when we’re doing our inspections with the infrared camera, we can see that insulation is present in the ceiling, but sometimes it’s lifted or it might just be a bit older, so it’s just degraded. What would you recommend is best here? So when we tidy up the existing insulation that’s already there or going over the top of that with new insulation, or is it best to remove the old existing and put brand new installation in? So, you know, what would be your preferred method there?


David Millard  26:10

Yeah, so it’s probably a case by case basis Anthony, whether you do rip it out or just go to the top of it. I know like doing renovation extensions, we come across insulation and it’s like probably only 30 mil thick. And like this thing’s not fonna help at all. So often with that, we just throw it out and, you know, sometimes it has water damage, you know, that squashed it. So when insulation is squashed, it loses performance. So with a batt insulation, it’s so fluffy, so you get lots of little air pockets. So when the insulation is squashed, you lose all the air pockets, so it doesn’t perform as well. So it’s probably a case by case basis to whether you keep it or throw it out. Yeah, as far as the way to install it… Insulation works really well, but 5% of gaps in your insulation actually decreases the quality performance by 50%. So it’s one thing just to say you have good insulation, but is it been installed correctly? So I find that insulation works, you know, when it’s just got the standard rows and the truss width works perfectly and it’s all just shoved in nice and neat there, the installer doesn’t have to worry about cutting anything, then it’s all good. But I find, once they need to start cutting things with a Stanley knife to fit in, you know, potentially around your roof members or wires or plumbing penetrations and all that sort of thing, that’s where I don’t know if it’s the lack of care of the installer, or whether it’s just ignorance, I’m not too sure,  probably a bit of both sometimes. So that’s where the real importance comes in to make sure you pay really important attention around all those details and that sort of thing. And as you said earlier, like just the importance of you know,if you can’t access your wall junctions now to put the insulation there, because obviously, if you don’t do all your wall junctions, you’re going to sort of you know, miss holes and that sort of thing. So the performance in your insulation is going to decrease quite significantly. One thing I think that gets overlooked too is like say you are installing insulation on your project or your home or whatever. I recommend to seal all the wires and plumbing penetrations go on there too, just where the… Like your bottom plate, which is a horizontal piece of timber on your wall, and then you have potentially noggins going horizontally across as well. Then you have another horizontal piece of timber right at the top near your cornice. The plumber or electricians will drill, you know, maybe a 25 millimeter hole and then they’ll shove like a, you know, say a six mm pipe or a 10 mil wire through, so you get left with like a gap there. So I recommend just using like a polyurethane sealant or any type of sealant. You just got to be careful that the sealant doesn’t react with the plastic wiring and also the plastic pipes and that but just to seal it up. That way you’ll stop that air leakage.


Anthony Jenkin  29:45

I know when we specify our ceiling insulation, so we’ll say maybe use a 90 mil thick insulation batt and we’ll run it between the bottom quarter of the trusses and then we’ll put another layer crosshatch over the top of that larger sized insulation batt. And that just helps again with thermal bridging, and, you know, has that thermal break from the bottom corner of the truss. So that’s another thing that people can do as well. And if you really want to go to that next level, you could look at layering that insulation, bulk insulation, yeah, that one direction, or then cross hatching it the opposite way, just to reduce that thermal bridging capacity.


David Millard  30:23

And for whatever reason, if you did have, in that first row of insulation, you did have like a minor gap, because you can’t get everything 100% perfect. But then you cross hatch it the other way so it’s gonna bridge that gap. So it’s definitely going to be well better performing.


Anthony Jenkin  30:42

So the next topic I want to bring up is windows. I’m putting this one sort of at the bottom of my list anyway, just because, you know, looking at this, this is a much higher price point. So we’ve sort of started with, you know, very affordable options using silicone for airtightness, you know, it’s really affordable to have the handful of dollars, and then right through to windows where we are now, which can be 10s of 1000s of dollars, or $10,000 a decision. So I just want to let you maybe provide some thoughts on what you think the best types of windows might be to use, or firstly, maybe things that you can do to your existing windows without having to look at replacing them.


David Millard  31:16

Yep. So I’ll probably start off with the most cost effective one first, and I find around windows and architraves, that that’s another spot we get leakage. So you know, a bead of caulk where your plaster board or your internal lining meets your architraves and any gaps around the architraves, I recommend sealing that up with like a cork, and then paint over it or silicone, whatever you choose. And, you know, that’s going to be the most cost effective way just to do something. But once again, you’re gonna have to get to that peak performance, it’s far from it. And then as far as you know, trying to prevent heat loss from your home, your blinds do a certain part of it, like a standard roller blind, it may help a little bit. But once again, it’s not going to do that much because they’re not that thick. They’re not cutting that need around your window on that. So you still are going to get quite a fair bit of leakage or cool coming through there. But another good one is like a loose, big loose, heavy drapes or curtains, that sort of fit, you know, pretty hard to your plaster wall on the sides. They go down to the floor. And you know, there’s just the like a big blanket virtually across your window, that they do a pretty good job. But once again to make that a hell of a lot better, you could have pelmets over the top. And not just a pelmet, make sure to, you know, seal it up too, that you do caulk across the top and that and also with the power too, you know, somewhere along the line, someone created just a pelmet that was a horizontal piece of timber that doesn’t do too much, you need to have it. So it’s the horizontal piece of timber and then the sides and that too. So it, you know, pretty much just encloses it. Because otherwise you get that convective heat loss coming up through. There is another option of the honeycomb blinds. Yeah, they’re a great thing too. Providing they are tightly fitted. Honeycomb blinds are virtually blinds that connect up and down. And when it’s open or when it’s closed, it creates just this honeycomb sort of air pockets. And you know, they work pretty well. But I do find that if they’re not tightly fitted, they’re not that effective. So they’re the sort of the major ones with the blinds, but you can probably see still that common trend of we want that continuous connection, we’re talking about, you know, with the caulking before, those little minor gaps, they just all create air leaks. And it’s the same with the windows and blinds and that, you know, just because, you’ve got a honeycomb blind or whatever, it’s going to work but if it’s not tightly fitted, it’s not going to work that well. And you know, same with your heavy drapes or blinds, that’s something if you’ve got the gaps, they’re going to leak to an extent. But I suppose after that you could, depending on the windows you have, you could look to retrofit double glazing on them. But this is where, you know, finalized prices start to go up a fair bit. Obviously, like a single 4mm pane of glass isn’t going to perform that well compared to a double glazed window. But it all depends on the type of window you have. So say for example, you do have aluminium windows, single glazed, you can double glaze your windows, get them double glazed, but you still got a thermal bridging on aluminium. So that’s going to create a fair bit of cold coming through. But the best option would be to rip out all your windows, install some brand new high performance windows. And while you’re doing that, you can ensure they’re installed correctly sealed up right around the outsides. And that’s definitely going to be your best option – but also definitely the most expensive option too.


Anthony Jenkin  35:53

Can we get you to walk us through how you typically seal up a new window once you’ve installed it? So let’s say someone has been able to afford to replace their old single glazed aluminium windows and they want to put some high performance uPVC double glazed windows in. Any tips about the installation of that window to ensure that it’s going to perform as well as the actual window does?


David Millard  36:13

How long is this podcast going for? I know you and I talk about window installations quite a bit. If it was in an old building and that sort of thing, it depends on whether we’re doing external cladding or we’re not. But let’s just say you were, we’re just ripping out the window, all the internal windings, all the external lightning is all staying in. Yeah, obviously rip out the window, put the new one in. But before I put the new windows in, I’d make sure that the timber frame is sealed up some way with some building wrap or some polyurethane sealant or some gaskets. Just to prevent… If your window does leak, to prevent it from getting damaged. Another thing I would do is I would install either a seal pan on the bottom of the window which is like a…sorry, on the bottom of the timber trimmer. A seal pan is a piece of PVC, plastic, that’s designed for if any water does leak through the window, to drain out and not go into your house at all and also not to damage your timber frame. There’s other products out there you can use. I know Pro Climate do have a product out there, seal tape, and that sort of thing, but it’s a matter of trying to… If water does get to your window, of having it dispersed out of the frame. And then once your window’s in, I’d recommend either expander foam or you can use the foam rods. And I’d poke that right around the outside perimeter of your window. Because when you install windows, you get left with like a 10-15 mm gap between your frame and the outside reveal of your window. And the majority of the time that is not sealed at all by the tradesman and you just get this murky, nasty big hole there. So yeah, I’d either seal it up with a foam rod or expander foam. And then I will also put a bead of polyurethane over the top of that and right around your window to seal it up, that was going to prevent air leakage. You know, you could even just shove insulation right around it, like just get little strips of insulation, just shove it in there. And that’s going to be better than doing nothing. It’s just about minimizing those little pockets where you don’t have any insulation, that’s where you’re going to get cold drafts not coming through. So yeah, that’s probably how I’d go about it, but there’s probably 1000 different ways to do it.


Anthony Jenkin  39:18

We want to hear how you go about it because you know, we’ve seen your detailing, it’s impeccable. So just add that if you go to use foam between the reveal and the stud frame, just make sure it’s a low expansion foam. Some windows, they’re prone to bow under the pressure of the expansion foam. And it might lead to some cracking in the glazing, which we want to try and avoid. That decision on whether you use expansion foam or bulk insulation probably just depends on the size of the gap in there and you know, is the reveal from the reveal to your window, is say 50 millimeters or more, you’re probably looking at bulk insulation. But if it’s sort of less than that, then expansion foam or even a backing rod closed cell foam backing rod. So just to mention, closed cell will prevent the moisture transfer coming through. But if you use an open cell foam backing rod, it’ll let moisture through. So we just want to avoid that. So particularly with the majority of architraves around windows as well, they are MDF and MDF is renowned to absorb moisture. And it can be quite destructive with the capillary action of water transferring through it to other areas. So, if you’d like to maybe share some real case study or real world application at all?


David Millard  40:28

Yeah, before we do that Anthony, I might have a chat about the ways that people can actually find air leaks in their home. So it’s all good, us chatting about, you know, sealing this, sealing that, you’ll see cracks now, but like, to actually, the best way to find where the draft is, is to actually test it. There’s heaps of different ways to do that, but here’s just a few that I recommend. On a cold windy day, you can actually go around with your hand, around windows, around your floor, you can actually feel the drafts. So that’s just a very basic one. Other good ways you can, once again on a cold windy day, you can use like an incense candle, or any sort of device that, you know, just continuously smokes. And you can see, you know, when you’re moving around, and you move your candle close to a window, or anywhere that’s a leak, you can see the smoke just starts moving a lot quicker. So another good way is, you know, the thermal imaging cameras. When it’s very cold and windy outside, you can actually sometimes pick up the air blowing through there and the other option is you can hire a great company, like yourself, to do a blower door test and actually, you know, find your leaks, because I do know you guys do that Anthony. So, you know, personally, it depends on how far you go on with things, but you could start off having a crack yourself on that and seal up as much as you can. But then if you still find that it’s leaking, then you might get the big boys in to do it for you.


Anthony Jenkin  42:15

We do offer air leakage and installation inspection on existing homes and look, couldn’t recommend it more to those listening. And what we do is, we will depressurize your home to 50 Pascals using our blower door and then we’re able to tell you where or what the air change rate is based on that test. And we get to identify where all those air leaks are occurring. You know, we’ll be able to then use the infrared camera, thermal camera, to look where insulation may be raised in your ceiling or if it’s not there at all. And then we can provide you with, you know, a nice bundled report that identifies these these issues and provides recommendations for rectification works and you know, some helpful tutorial videos as well and some products in that report that you can then carry out some of that work yourself.


David Millard  43:02

Sounds like a wise investment. I suppose I’ll also just touch on that. I know if you’re probably sitting in your home right now or listen to this podcast and it’s cold outside and you’re feeling quite cold in your house, that you’re probably a long way off what I’m about to speak about, but I just want to put it out there and that’s something for the listeners now just to be mindful that when we’re trying to seal up a home, I believe that we’re walking a bit of a tightrope of one side, you know, you have a leaky drafty home and on the other side, you run the risk of mold and condensation build up. But like I said if you’re sitting at home right now and you are cold and you plan to just cork up a few bits and pieces, you’re probably miles and miles off risk of mold and condensation build up. I just wanted to put it out there and if you do engage a company like Anthony or someone to do blower door testing or you’re curious to know what leakage your home is at that anything above five air changes and I’ll let you talk about the nitty gritty of the changes Anthony. But anything above five you know, I believe is at risk of mold and condensation build up, but once you start getting between this level of three and five air changes now, you know, you may need a HRV unit and then definitely once you get below that three air changes per hour, I believe you’re going to require HRV, you know, to ventilate your home and I’ll let you talk Anthony about you know, air changes per hour and HIV unit, that sort of thing.


Anthony Jenkin  44:51

So David, is there an example that you might be able to share with us today that touches on all the things that we’ve discussed?


David Millard  45:00

Yeah, so it’s probably not a real life example. But it’s just an example case study that I think might be very common here in Australia. For someone’s story, from, you know, making their home energy efficient and sustainable as possible. So say for example, a freshly married couple have purchased their dream home. And it’s an old Victorian cottage. And one day, they have the dream of renovating and do an extension, that sort of thing. It’s quite livable as it is, but you know, they definitely want to do a few things to it. So the old cottage has got the hallway through the center. And then you have two rooms, either sides of sort of four front rooms of the house. And, you know, one day they think that, you know, we’d like the forefront rooms, and you know, maybe heritage or something over it as well. And that seems so they can’t sort of do too much of that. But, you know, the old sort of extension, I do find with the Victorian cottages, you may have an extension on an extension over a period of time. So I think that’s perfect. We’ll just knock down the back part of the house now and leave the forefront rooms. One day, they say. So, they spend their first winter in their home and they think, oh my god, this is so cold, we cannot bear this. So over the next year, they start to figure out how can we improve the performance of this front four rooms, obviously don’t want to do too much to the back part of the house with the idea they’re going to knock that down. So they do decide to spend $30 on a few tubes of silicone and cork just to seal off the back part of the home and just to try and prevent the draft and that sort of thing. But they decided to put a bit more money into the front four rooms in the house. So there’s good access underneath the sub floor, so they decide to go underneath there and insulate that with some good quality insulation. And they do the same with the roof. They go around and cork everywhere. They install weather seals on their front doors. And there’s unused chimneys in the old rooms too, so they’ve decided to block them off as well. So yeah, the house is you know, it’s done to an extent and still not perfect, they don’t have any insulation in the external walls, but you know, they got warm feet with underfloor insulation, and they got the ceiling insulation as well. So yeah, they’re quite happy with what they’re done. So a few years go by, and the old timber weatherboards on the four front rooms of the house require replacing. So they decide to arrange a tradesman to pull off all the old weather boards and bring the house back to a good condition just on the front four rooms. While doing that, they decide let’s throw in some insulation in the walls, let’s actually batten out the studs and so instead of bring a traditional 90 mil stud wall they decide to put on a 45 mil batten to increase the thickness of their insulation they can do with that. They also get the tradesman or the builder to correctly install the building wrap as well and also install a ventilated cavity which I won’t go into details of the ventilated cavity right now. And they also decide to rebuild all windows and install high performance windows just to the four front rooms. So again, the four front rooms of the house have been done in different stages. And the four front rooms are definitely quite livable. So then after 10 years of purchasing their dream home, they finally have enough funds to go ahead and completely renovate and extend the home, so they do a nice extension out the back. The extension is done with thicker walls and additional construction to get some good insulation in there. While the plasterer is there, he actually goes through all the front four rooms and covers over any of the old vents in the walls to stop the air leakage. They repolish all the timber floors in their home in the four front rooms. So that’s been you know, it was leaking and drafty. But now they’re recoated, it’s all been sealed up. And, you know, potentially their client could install HRV right throughout their home to ensure that you know there’s not going to be any risk of mold and that sort of thing.


David Millard  49:57

So like, you can see that it doesn’t need to be done overnight and doesn’t need to be done within 12 months, it can be done within a 10 year period or 20 year period or even a 30 year period, it doesn’t matter, I think is the biggest thing I want people to take away from this, as long as you’re taking small steps, you’re going to get to the right, the right endpoint, it’s just a matter of just taking it step by step. And it all depends on how far you want to go to, like, I know, you can renovate a house over 20, 30 years to get it to be a benefit, which is a renovation of a passive house standard. You can do that over a period of time too, or you can also just, you know, improve your insulation, improve your airtightness, and just have a, you know, a better performing home than a standard home. That’s the thing. So I think that’s one of the biggest takeaways, I think I want people to get, Anthony.


Anthony Jenkin  50:50

So we have one last question for you, David. This is a question we ask everyone that we have on the podcast. It’s about the future of our industry, and where do you believe it’s heading? So if you could change one thing in the building code, what would it be?


David Millard  51:07

Yeah, that’s a tough one. It’s very hard to narrow that down to one. But if I did have to – and I got enough related to insulation – that I would love to see mandatory waterproof inspections. I think that water is the biggest killer of homes. And, you know, we have a frame inspection, which is great, you know, not saying we shouldn’t get rid of frame inspection, but I just see all the time with projects, water leakage in wet areas, and that creates mold, rotting of timber frames, it just creates so many issues. And I believe if we did bring in a mandatory inspection for waterproofing that, if it’s been ticked off correctly, that it’s going to make huge difference to the homes going forward. With you know, making sure it’s all been done correctly, and that if I could change something that that would be it.


Anthony Jenkin  52:09

I chatted about this past in the past on a few occasions, and you know, we know that water is the number one killer of homes. So that’s a really good one.


David Millard  52:18

Like, it’s funny, like there’s a mandatory frame inspection, but like, how many homes do you actually see, like completely fall over? You do see minor structural defects and that sort of thing, or large structural defects, don’t get me wrong, but I believe not as many as you see water issues, and that related from waterproofing defects and that, yeah.


Anthony Jenkin  52:39

I’m sure that as a builder, you would never receive a call, let’s say at 2am in the morning for any other reason other than my home is leaking water.


David Millard  52:48

That’s it. Yeah, for sure. Yeah, is anyone from the ABA listening? Take that on board.


Anthony Jenkin  52:55

Well, thank you again David, for coming on the podcast. It’s been a pleasure. And I think some really valuable information there that homeowners listening will be able to implement into their own homes this coming winter, to be more comfortable and approve their energy efficiency.


David Millard  53:10

Yeah, awesome. It’s been really good guys. Appreciate you having me back. And, who knows, we might chat again soon.