An insulation problem...

Did I mention that my basement used to be a crawl space?  Hmm...maybe I didn't.

The guy across the street is actually the one who bought this house in the late 90's and converted the crawl space to a full basement.  He's a builder with an awesome house and a large pickup that leaves at 6:30 every morning like clockwork.  He called me over one day and showed me a couple pictures of the project.  Impressive.

Anyway, his work left me with an insulation dilemma.  Because the first 4-6' of the basement is new, there is a "step" around 3/4 of the basement, where the new cinder blocks meet the old bricks.

So you notice how I have the rigid foam board on the top and the bottom, but nothing in the middle?  I considered laying insulation batts over that space, but quickly abandoned the idea when I imagine them  turning into sponges.

I first learned about the perils of basement insulation when...who would have expected it...when reading Amazon reviews for the best basement remodeling book available: Remodeling A Basement Revised Edition.  Everyone loves the book, except for a couple guys who disagreed with the author's approach of using insulation batts directly against the concrete wall.

These reviews sent me on a wild Google-based research project about basement insulation techniques.  It seems like a really controversial subject.  I mean, how many times have you been in a finished basement that smells like a basement?  The standard approach is to put the studs right against the basement wall, fill the center with insulation batts, and then cover the inside with a vapor barrior.  Some people think it works, others think it's crazy.  Apparently the batts wick the moisture from the walls and the vapor barrier holds the water in place.  The result is that the batts lose a lot of R-value and become a nesting ground for mold.  This whitepaper (pdf) on the US Dept of Energy's website helped confirm this line of thinking, along with a bunch of other articles.  It just made sense to me.  So I decided to go with the foam board / spray foam plan against the wall.  I also plan to fill the stud cavities with batt insulation, so I'll have all three!  The triple play!

Back to the spray foam...YouTube has a few videos showing their awesome power.  Julie can attest to the fact that these videos got me a little too excited.  I think I just wanted to wear one of those suits and watch the foam fill in all the cracks! I could watch those videos over and over again.

In the next post, I'll tell you about my experience with the stuff...