Basement Insulation Eugene, OR

Concrete Does Not Insulate

A foundation wall conducts heat straight into ground that stays cold and wet for much of the Oregon year. Insulating on the interior face with closed cell foam puts a continuous thermal and air barrier between the living space and that concrete, and because it adheres directly to an irregular surface it does so without the gaps that framed-and-batted basement walls almost always leave behind.

The Rim Joist Is the Quiet Culprit

Where the floor structure meets the foundation there is a band of framing, often uninsulated, often with gaps straight through to outside. It is one of the largest air leaks in a typical house and one of the least looked at. Sealing and insulating the rim joist is a small, contained piece of work with a noticeable result, and it is usually done at the same time as the walls.

Moisture Before Insulation, Always

Efflorescence on the concrete, damp patches, or water arriving after heavy rain all have to be understood before anything is applied to that wall. Closed cell foam is a vapour retarder, which is an advantage in a dry assembly and a way of hiding a problem in a wet one. If there is an active water issue we will say it comes first, because insulating over it only makes it harder to find later.

Finished and Unfinished Basements

An unfinished basement is straightforward: the walls and rim joist are accessible and the work is quick. A finished basement means the foundation wall is already covered, so the honest options narrow considerably and often come down to doing the work when the space is next opened up. We will tell you which situation you are in rather than quoting around it.