Block foundation insulation ideas

[jMoon]

Hey guys I’m just about done insulating in my garage and looking around I figure I should probably do something about my foundation as well.

My initial plan was to fill up the cores with spray foam and screw a 1x4 on top so it would have a paintable finish and sit pretty flush with the edge of the wall. But now the more I read I’m kind of getting the vibe that insulation in the cores is kind of a waste of time.

Any ideas? Foam insulation board on the tops and sides? Not sure where to go with this.

Thanks for the help. Here’s a pic so you kinda have an idea of what I’m working with.

https://i.imgur.com/swNdwIW.jpg

 

[74nova350ss]

Insulate on the outside of the wall/foundation. Foam sheets as thick as you can apply, 2" ideal, down to about 4 foot (frost line).

They make some with a stone like texture already applied.

 

[EdT]

One thing to consider is that block walls are often quite porous and air can infiltrate right through them. So something that seals against the passage of air would be worth thinking about. If you decide to insulate the leakiness may take care of itself.

 

[NUTTSGT]

The back wall of my garage is block. I tap-conned 2x4s flat against the wall, added some (polystyrene) in between them with a covering of OSB for the interior walls. The 1 1/2" is like a R6-7 and then I added some 3/4 on the outside, covered with OSB and topped with vinyl siding.

The back wall was always cold and sucked the heat out of the garage. Simply put, what little I added was way better than it was before.

 

[Musicinabottle]

They typically put Styrofoam beads like those used in bean bags withingthe CMU cavities.

 

[yeldogt]

Foaming the blocks is as much about air leakage in old cinderblock as it is about R value -- old brick block construction leaks a surprising amount. Modern cement blocks don't

How high is the foundation above the ground ? Typically a "foundation" it's filled with concrete ? Is this a wall?

If we are just talking about a couple of feet -- 2x on the flat with 1.5 foam board will get you a good thermal separation ...


I'm not seeing any pictures.

 

[Randy in Maine]

I put 2" of foil covered foam on the inside of my crawlspace under my house as far down as I could go (~3') and taped all of the joints. I used Topcon screws and fender washers to keep them attached to the concrete block foundation. My pipes down there don't freeze anymore. Cheap money well spent.