Jackson Digney shows how to eliminate thermal bridges in Passive House construction. The Californian corner uses spaced noggins to fully insulate corners and prevent cold spots. At windows, high-density expanding foam fills the gap between frame and wall, blocking thermal bridges and air leaks.
We've just talked about glazing and, and how picking the right frame with your glazing plays a really big part in one of the other pillars of a Passive House, which is eliminating thermal bridges. There are a lot of different areas where thermal bridges can occur in a house, and one of them is at the junction of exterior walls. Like we have Right here. Traditionally, an exterior wall is constructed with a double stud on the corners, and the problem with that is that there is a pocket left over that is really difficult to insulate and results in a cold spot when you come to finishing the house and doing your thermal imaging. And that cold spot also leads to mold growth. Here, what we've done is what's called a Californian corner. So instead of having an extra stud for the plasterboard to come through and connect to, we've got a series of noggins in place spaced at 600 millimeters, which picks up the plasterboard. But most importantly, it allows us to tuck the insulation all the way in behind the corner, and it prevents cold air from coming through into the building because it's insulated properly. The other place where thermal bridging can occur And, and can undermine spending the money on good windows is when the windows are installed. So you can see here that there is a gap left over between the windows and doors. Now commonly in Australia, all that's done to seal this up is the plasterboard is installed and then a little bit of caulking. And the problem with that is you've still got the cold air coming through here. So right now we're gonna show you what we do to stop thermal bridging around windows. Sealing around the windows is really important for thermal bridging as well as for airtightness. And it's critically important that you make sure that your builder fully understands what they're doing with all of these different products so that you actually get what you're paying for. So here, what we do to fill this gap before any other treatments is we fill it with a high-density expanding foam, which in the case is a product by Hilti, and we'll show you what we do. It's really straightforward, doesn't cost a lot of money, and it will eliminate the thermal bridge, and it will also make the seal of the window to the wall frame airtight. If you want to know more about building a Passive House, download our guide to the 5 key skills of a Passive House builder.
