Replies

1. 
   Richard Beyer | Sep 20, 2014 09:28pm | #1

   Backer rod and caulk. If you use drywall compound the water/moisture will wick up the drywall from the foundation.

   See... http://www.homedepot.com/p/MD-Building-Products-1-2-in-x-20-ft-Caulk-Backer-Rod-71480/202066515

2. GBA Editor
   Martin Holladay | Sep 22, 2014 04:57am | #2

   Rob,
   Q. "Without performing a blower door test, how "bad" do you think this gap is from an air-sealing perspective?"

   A. It's always a good idea to make sure that the wall that separates a garage from indoor living space is as airtight as possible, since the air quality in your garage is likely to be low compared to what you want in your house.

3. 
   Richard Beyer | Sep 22, 2014 10:40am | #3

   Nice call on IAQ Martin...

   http://garages.about.com/od/buildingagarage/a/garages_and_indoor_air_quality.htm

4. 
   rhallen645 | Oct 04, 2014 07:22pm | #4

   Thank you for the advice. 80 feet of backer rod and 4 1/2 tubes of caulk later, the gap is sealed. I was shocked to find a wide-open 1" diameter gap just below the door molding that extended up the wall and quite a ways underneath the interior of the first floor. I sealed this gap, but now I fear finding gaps everyplace I look in the house!

   Pictures attached...apologies for the off-centered angle.

5. 
   natnaelh | Apr 24, 2015 03:43pm | #5

   Hi. I have the same problem as Rob. The only difference with my attached garage is the gap is 1" wide in most of the area. I have bought a backer rod and Sikaflex Construction Sealant (Polyurethane caulk). Can I use polyurethane caulk for 1" gap?