Snow Outside, Toasty Inside

The Snowmageddon all the forecasters were warning us about seems to have fizzled out overnight, as this was all we had when we awoke this morning.  Just enough to cover up the solar panels.  It's still colder than a well digger's belt buckle, though.  I guess we're skipping fall here and going straight to winter.  Bah!

The unpleasant weather is the perfect excuse to stay inside, so we spent the day working on insulating the rim joist in our basement.  This was a to-do from the energy audit that we had done in the Spring.  Apparently, beyond beefing up your attic insulation, insulating the rim joist in your basement is the second best thing you can do to improve the energy efficiency of your house.  Even if you have a brand new house.  There's a huge amount of energy that is lost from holes around service wires coming into your house and the airflow between your foundation wall and the rim joist.  

It's fairly simple to fix with some insulation.  The pink fiberglass stuff does not work for this, though, as it's terrible at stopping air infiltration!  Instead, you can pay someone an exorbitant amount of money to come in and spray foam everything or you can do what we did and opt to use rigid foam.

Not our house - our foam is baby blue

Basically, you just need just a few things for this project:

1. A sheet of 2" rigid foam that's available from any hardware store
2. A sheet of 2.5" screws to secure the foam to the rim joist.  Don't go longer than that or you'll poke through the outside!
3. Spray expanding foam (like "Great Stuff")
4. A retractable utility knife

And here's how you do it:

1. Measure the cavity between the joist.  (We measured them all and just wrote down the measurements so we could cut the foam outside.  It does make a mess.)
2. Subtract 3/4" to 1" from the height and width measurement.  This will allow for the expanding foam later.  If you cut the foam too tight, it will be hard to get the foam in there.
3. Use the utility knife to cut the foam to your measurements.  
4. Center the foam in the space and then use a screw to secure it to the rim joist.  Then go around all 4 sides and fill the gaps between the rigid foam and the wood completely with expanding spray foam.  Voila!  No more drafts.

It's 22 degrees outside right now and, as we worked, we found areas where cold air was literally pouring in over the foundation wall.  The temperature in our basement immediately and palpably went up with each piece of foam that we installed.  While we were at it, we added some additional spray foam to the basement windows as well.  It took us about 4 hours to do half the basement, so this is a full day project.  The other half will have to wait until next weekend, as we're out of spray foam.  And energy.