Replies

1. GBA Editor
   Martin Holladay | Oct 15, 2018 03:13pm | #1

   Ed,
   The above-grade portions of the wall should be insulated like any other above-grade wall.

   The below-grade portions of your wall should be insulated like any basement wall. Here are two articles to get you started:

   "How to Insulate a Basement Wall."

   "Fixing a Wet Basement."

2. Expert Member
   Dana Dorsett | Oct 15, 2018 03:14pm | #2

   I'm not sure what means "...has siding wrapped..." in 'merican dialect (?).

   Fiber insulation in contact with foundation is not a great idea, nor is a polyethylene vapor barrier on the interior. An inch of closed cell spray polyurethane on the foundation would dramatically reduce the amount of ground moisture getting into the studwall assembly, and would provide enough dew point control for filling the remaining 2.5" with compressed fiber, with NO interior side vapor barrier, as long as the assembly is reasonably air tight. If the old R13s aren't moldy it's fine to re-use them, otherwise 3" thick rock wool fire & sound protection batts would be slightly better

   Explain the wall's material stack-up for the above-grade part of the wall, which may have a bearing on the total solution here.

   [edited to add]

   From the picture it looks like there is quite a bit of distance between the studwall and foundation? If that's the case my prior advise doesn't quite fit. How much distance is there between the foundation & studs?

3. 
   edbaker79 | Oct 15, 2018 03:46pm | #3

   Thanks for the quick responses. they have multiple layers of siding on the exterior with vinyl siding being the latest outside layer.
   I will provide some better pictures and measurements on the exact distance between the foundations and stud wall.

4. 
   edbaker79 | Oct 16, 2018 01:48pm | #4

   so the distance between the studwall and foundation is anywhere form 2 to 4 inches but yeah the original builders did not go flush to the foundation.
   any new suggestions per this new information?
   thank you

1. Expert Member
   Dana Dorsett | Oct 16, 2018 07:16pm | #6

   Unless you're going to re-build the whole wall, 2" of HFO-blown closed cell foam on the foundation would get you to code-min for foundation insulation, but it's expensive a about $2.50-$3 per square foot.

   What's on top of the foundation wall? (Do some archaeology and figure out what all the layers are, siding types, underlayments, sheathing, insulation etc.)

5. GBA Editor
   Martin Holladay | Oct 16, 2018 02:39pm | #5

   Ed,
   Did you read the article on insulating basement walls? Your two choices are closed-cell spray foam or rigid foam, installed tight to the foundation.