EXPERT ADVICE
Maxwell: Building with panels beats using stud frame
February 13, 2010
Steve Maxwell
SPECIAL TO THE STAR
Q: Where can I buy structural insulated panels (SIPs) and where can I learn how to build with them? We're planning to build a cottage this spring.
A: I've built with SIPs on three projects over the last four years, and given how well the resulting structures perform, I probably won't be building many wood-framed structures again.
Instead of studs and plates, these rigid panels form the entire load-bearing structure for walls and even roofs.
If you search "structural insulated panels'' on Google you'll find Canadian SIP suppliers. Although working with SIPs is simple, it's entirely different than building houses in the usual way. Check out the book Building With Structural Insulated Panels by Michael Morley for a detailed look at exactly how to work with this material.
Q: What are my flooring options for an uneven concrete basement floor? I'm looking to replace carpet and we suffer from allergies. The floor is sloped a bit for drainage and the basement has been dry for seven years since we had a sewer back-up.
A: You're right to be interested in a hard surface floor. This is my favourite, too, but the trick is selecting an option that'll work over your uneven basement floor, while also being water-resistant to a certain extent. No matter how dry a basement has been, recently, it's still a hole in the ground and gravity wants to fill it with water.
Fiberfloor (www.tarkettna.com; 800-465-4030) is one option that I have personal experience with. It looks like an extra-heavy vinyl flooring, except that it's very floppy and lays down flat under its own weight without glue. Fiberfloor is quite tough, comes in a variety of colours and patterns, and can be lifted, removed and dried out in the event of a flood.
The only drawback is the need for precise cutting during installation. It comes in large sheets and needs to be trimmed to fit the perimeter of the room.
Another choice is vinyl plank flooring. This relatively new option is offered by a growing number of companies and is also able to lay flat over somewhat uneven subfloors. Product shape is the main advantage. Since each plank is relatively small (typically four or five inches wide and four feet long), it's easier to cut and fit them around the edges of your room.
Vinyl plank floor has peel and stick interlocking edges that bond with neighbouring planks while allowing the entire installation to float.
Q: Will a vapour barrier stop frost from forming behind the basement walls I'm building? Last week I had to temporarily remove insulation batts from between a few floor joists and I found frost where they met outside walls.
A: As warm, moist indoor air made its way past your unprotected insulation, it cooled down as it got closer to the outside wall. And the cooler air gets, the less moisture it can hold. Eventually, this air reaches 100 per cent relative humidity, after which further cooling causes moisture to appear and freeze.
Although a properly sealed vapour barrier prevents condensation, that's not always easy to achieve. It's simple enough when you're dealing with an ordinary wall surface, but quite challenging where floor joists meet the outside wall. In fact, I'd argue that it's impossible to create a complete seal because of all the adjoining surfaces. This is why I recommend spray foam insulation in these locations.
It's warm and seals air infiltration, preventing condensation and mould growth.
Although batts aren't my first choice for basements, since you've already got them up, go with them for the walls.
Where floor joists meet exterior walls, however, I'd consider removing the batts and using spray foam.
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Steve Maxwell, technical editor of Canadian Home Workshop, runs Saturdays in New in Homes & Condos.
Toronto Star