image via David Goehring
Do some of your rooms feel chillier than others? Perhaps you have tried to solve the problem by adding extra insulation to your walls, or by opening your heating vents wider. However, there's a possible suspect you're probably not considered: your cantilevers.
Think about the rooms in your home that get cold. Do they happen to be those with cantilevered floors? In the summer, do the same rooms seem to be hotter than the rest of the home? If the answer is "yes," then chances are good that your cantilevers are not insulated. This is a common mistake among sloppy or inexperienced builders -- they fail to insulate the overhangs. If this happens to be true in your situation, you're not alone. Many homes in the US have poorly insulated cantilevers, and the owners rarely figure out that this is the source of their problems until a professional comes to check it out.
Insulating the cantilevers in a new home, while it's under construction, is a rather simple process. Spray foam insulation is simple applied between the floor joists before the subfloor is nailed down. When this task has been skipped during construction, adding insulation to an overhang floor becomes a bit tougher in an existing home -- but it's not impossible, thanks to spray foam.
Polyurethane spray foam insulation can be used to insulate an existing cantilevered floor without removing the subfloor or disturbing the home's interior. Since the foam starts out as a liquid and then expands, it can be inserted into the floor through small openings. Once the foam has cured (which only take a a day or two) your home temperature will be much more even.