Insulating concrete walls

Building Science.com contains many of the most recent advancements in building techniques. It even provides complete residential designs depending on which climate zone your house is located at.

My house is located in a mixed-humid climate, and one of the recommendations is to use foam insulation on bare concrete walls, with thickness of at least 1.5 inches (especially if this was not done on the outside of the house).

A money saving tip - using 2 layers of 3/4 inch foam is considerably cheaper than 1.5 inch foam. Apply foam such that no seams overlap. Use glue specifically for foamboard. On the final layer, tape seams with Tyvek tape.

Next, isolated framing and moisture sensors...

Completed adding more mass to basement ceiling

In my last post I mentioned a short cut for adding layers of sheetrock to the ceiling between the joists. Gervais recommends putting up one layer of sheetrock at a time, and apply foam backer rod with caulking around the gaps for each layer.

Instead, I cut the sheetrock so that the 3 layers were still joined by folding the sheetrock. This allowed for putting all 3 layers up at once. I then used spray foam to seal all the gaps. I ended up doing about half the work myself. Both the builders and I found it took about an hour to do each joist gap (about 14ft in length). With about 30 joists in total, this is a considerable time investment. If I had followed the exact technique described by Gervais, it would have taken at least 3 times as long.

In terms of physical work, it will easily be the most difficult task in completing my basement - and its complete!

Before:

After:

See photo gallery for more images.