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HOUSE WORKS: Insulating a cottage; outdoor crafts and circular windows


Rigid foam applied on top of a subfloor is an effective way to make floors warmer. The second subfloor is fully supported by the foam underneath, providing a surface for finished floor installation. - Steve Maxwell
Rigid foam applied on top of a subfloor is an effective way to make floors warmer. The second subfloor is fully supported by the foam underneath, providing a surface for finished floor installation. - Steve Maxwell

Q and A with Steve Maxwell

Insulating lakefront cottage

Q: What are the best insulation strategies for a lakefront cottage that was never insulated? This place has a crawl space that allows access to the underside of the floor joists, and the walls are stud construction that can be accessed by removing some of the exterior wood siding. The roof is a low-slope metal installation but has no attic access as there is very little room available between the ceiling and the roof itself.

A: The first thing to understand is that you need to have a truly weatherproof exterior wall surface. If it’s easy to remove exterior wood siding to add insulation, then I’m thinking driving rains might also get in depending on how you seal things up afterwards. Are your exterior walls up to the job of keeping a sealed an insulated wall cavity dry all the time?

Spray foam is a great option for your walls, but it’s expensive. You might also have trouble finding a spray foam contractor who’d come to your cottage, though this is getting to be less and less of a problem.

One big thing to keep in mind is the dangers of insulating an exposed floor frame from below. Lots of people do this, but insulation can sag over time and they attract mice and other small creatures. And though spray foam works well, it’s a favourite thing for ants to chew into. The very best way to insulate a floor over a crawlspace is from above, with two-inches of extruded polystyrene foam placed over the floor inside, then a new 5/8-inch plywood subfloor added on top. This makes a huge difference to the warmth of the floor, and the insulation is safe from vermin.

Insulating a floor from above like this is the best approach, but the floor still won’t be super warm in the coldest weather. If that’s your goal you should consider electric infloor heating. The best I know of by far is made by Schluter.

Glue for outdoor crafts

 Type III PVA glues like this one are safe, suitable for long-term outdoor exposure, odour-free, they clean up with water and they’re waterproof when cured. - Steve Maxwell
Type III PVA glues like this one are safe, suitable for long-term outdoor exposure, odour-free, they clean up with water and they’re waterproof when cured. - Steve Maxwell

 

Q: What’s the best kind of glue to use for quick bonding of wood for craft projects that’ll live outdoors? I’ve been using a hot-melt glue gun but the projects don’t hold together well over time.

A: I think you’ll find any of the type III PVA glues work well. Titebond III is my favourite. It looks just like regular wood glue and washes up with water before it cures, but it’s very resistant to water after it cures. This is an amazing glue and I always have a bottle in my workshop. The only challenge might be the need to hold the parts for 30 minutes or so while this glue grabs. Hot melt is more or less instant, but not so a liquid glue like Titebond. You might consider a strategy of applying the liquid glue as usual, but also using a small blob of hot melt just to hold the parts together while the Titebond dries. This two-glue approach has worked well for me over the years.

Circular replacement windows

Q: What’s the best way to get replacement semi-circular windows for my older home? Do I have to build my own wooden sashes, then get a double-pane glass unit built to suit?

A: In the past I’ve had custom double-pane glazings made to fit specific wooden window frames I’ve built. I haven’t had round ones created, but I have done octagonal. I know semi-circular is available custom made. I went to a local building supply outlet and they had a connection with a glass manufacturer. You might want to try going to a glass place first-off.

Another approach is to buy a replacement window unit custom built. It’s amazing how many window manufacturers are set up for custom-making entire window units of any shape.

Steve Maxwell is a syndicated home improvement and woodworking columnist who has shared his DIY tips, how-to videos and product reviews since 1988.

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