It's going to be -15 when they install - will the foam insulation even work in that cold?

Yes, professional spray foam insulation will work at -15°C, but the installer needs to use cold-weather formulations and proper techniques. Most quality polyurethane spray foams are designed to cure effectively in temperatures as low as -18°C (-0°F), though they may cure more slowly than in warmer conditions.

Cold weather foam application requires specific considerations that experienced installers know well. The foam containers and application equipment need to be kept warm before use, and the installer should use foam specifically rated for low-temperature application. Some installers will warm the window opening slightly with a heat gun before application, and they may need to allow extra curing time before trimming excess foam.

In Ottawa's winter climate, professional window installers regularly work in these conditions and come prepared with the right materials. However, extremely cold temperatures can affect the foam's expansion rate and final cure, so a good installer might recommend scheduling the work for a slightly warmer day if possible, or take extra precautions to ensure proper application.

The bigger concern at -15°C is actually the comfort of your home during installation and the installer's ability to work safely. Most professionals will work efficiently to minimize heat loss, using plastic sheeting to isolate work areas and completing one window at a time. They'll also ensure the foam fully cures before finishing the installation.

For a winter window installation in Ottawa, discuss the temperature conditions with your installer beforehand. Ottawa Window Pros and other experienced local installers know how to handle these conditions properly and will advise if conditions are too extreme for quality work.