Flash and Batt Test Results

Flash and batt insulation is a hybrid of a 1 to 2 inch layer of closed-cell foam and fiberglass or cellulose to fill in the rest of the R-value. The idea is to use spray foam sparingly just to air seal and then fill in the balance of the R-value with a something less costly. It's a good system as long as you consider the right thickness for the spray foam to avoid condensation problems. Let’s take a look at how it performed on my house.


The results of the test are arranged into 3 segments:

  1. Test setup - shows how the test bay was assembled.
  2. Normal Winter - shows the test bay performance against the control bay on a moderately cold winter night with no wind.
  3. Extreme Winter – shows the test bay performance against the control bay on a day that is either extremely cold or has a 20 mph wind. The process used to simulate an extreme winter day is to depressurize the space to 50 Pascals, a pressure 5 to 10 times normal pressure. Depressurization with a blower door is commonly used to locate air leaks in a structure.

Test Set Up

Normal Winter Test

Extreme Winter Test

Return to Best Insulation Experiment page from Flash and Batt Results page
Go to Flash and Foil Results
Go to XPS and Foam Sealant Results
Go to Fiberglass Results
Go to Spray Foam Results
Go to My Conclusions from the Tests
Go to Experimental Design