My home was so bad on insulation I had no choice but to take make it my next home improvement project. And that meant tearing down the basement walls and start at the cold, gray, concrete foundation. This may not be an available option to some, but it at least gave me an opportunity to research and uncover some home insulation tips I could share.
Let’s start with the facts. Old homes are terrible when it comes to insulation. There was no such thing as best practice when these homes were built. Building science about how a home breathes (more technically known as the building envelope) didn’t come around in earnest until the 1990s.
Staying warm in an older home during the winter months (without selling your first born to pay for the utility bill) is no easy home improvement task nor is it cheap. The attic is as big of a culprit as your basement, or your exterior walls, or your windows.
The window contractor will tell you it’s the windows; The HVAC guy, the furnace; The pink panther, the insulation. When in truth it is all the above.
I chose to start in the basement. Why? because it was honestly the easiest place for me to start. The windows were the worst in the entire house and many of the foundation walls were bare block.
Basement Insulation tips and best practice…
Here is a quick recap of my research into the best practices to insulate a basement in Omaha and the Midwest.
Tip #1: Rigid foam board insulation provides a multi-purpose moisture barrier and blanket coverage glued directly against the foundation.
Tip #2: Kraft faced fiberglass insulation looselyinstalled between 16-inch on center studs carries the bulk of the thermal performance.
Tip #3: Use Spray foam insulation around all the old framing including sill plate, rim joist and foam board joints.
Tip #4: Add R-25 unfaced fiberglass insulation inside of each rim joist cavity.
Side notes on insulation…
* R-value is the rating system used to grade insulation products. The R stands for resistance. The higher the R-value the greater the insulating power.
* R-13 insulation or greater is recommended in the Omaha, Midwest zone 5 climate.
*I used R-5 one-inch Owens Corning polystyrene foam board + R-11 fiberglass totaling R-16.
* There are no second chances on a basement finishes so I used a ton of spray foam.
* Hands down, if cost is not a factor, closed cell spray foam is king.
*My home was built in the early 1950’s without a sill plate membrane. A flat 2×6 laying on concrete is a serious culprit for gaps and cracks.