Insulation concrete block Garage

[tigeraid]

Hey guys, new around these parts but hoping to start up a project thread soon--moving to a new house with a new shop!

It's just being used a shed right now, though, and is bare concrete block construction. I plan to insulate the roof with batting, but I'm needing some clarification on insulating the walls.

I'm in Southwestern Ontario and winters, particularly because of the wind, can be extremely cold at times. I'm open to insulating either the inside OR outside, whichever is preferred... But I'm confused on the whole "moisture barrier" situation.

If I insulate inside, can I:

1) use 2" rigid right ON the bare blocks, using poly adhesive?

2) Can I then strap and drywall right on top of it?

3) OR stud, insulate with batting, then vapour barrier, then drywall?

OR, do I need to do something to the bare block wall BEFORE I use the rigid foam? This is where I seem to see a dozen different answers. I've heard Tyvek suggested, I've heard just using a good water sealer/primer paint, and I've heard even vapour barrier FIRST, though that sounds wrong to me...

Or do I just do it outside the walls with 2" rigid foam only?

Thanks!

 

[buddyboy]

since you're not going to condition it every day, I would put rigid foam directly on the block on the inside of the building.

that way when you fire up the heat, the warm air will not hit the cold block and condense into water.

they make a foam panel that has built in furring strips, if i were you I'd use that.

using water proofing paint won't stop condensation, and if you water proof both sides of the block you'll just trap moisture in the block.

if you put the foam on the outside of the block, it will take longer for your space to heat up, because you have to now heat the block. but once the block is heated it will stay warmer longer. if you were heating everyday might go this route, only heating on the weekends then put the foam on the inside for sure.

good luck

 

[tigeraid]

Ahhhh.... Okay. But what if, in the future, I install my nice little furnace and leave the stat at, say, 10 degrees C? Would that strategy then backfire because I couldn't keep the blocks heated directly?

 

[tms0425]

I used InsoFast panels on mine and am very happy with the installation. They can be used on both inside and outside if you choose to. There is a lot of good info for planning on their website. These guys came from the ICF industry, trying to build a better mousetrap.

www.insofast.com

 

[Slowgsr]

Your foam interior I think is a great idea, they actually make a track system and the track gets screwed to the wall as it holds the edges of the foam panels against the wall, then you can screw your drywall to the strapping since interior foam will need to be fire rated.

 

[JWVan]

There are "Z" purlins that hold the rigid insulation in place, flat portion against the block, 90 degree along edge of insulation board, with another flat to go over the edge of next sheet. These are used commercially available.

 

[tigeraid]

Fascinating. I guess interior rigid foam it is!

Hope to start a WIP thread soon.

 

[tigeraid]

Would just the 2" rigid suffice for keeping the place reasonably warm in the winter? Not for working in (that'll be next year) but just for keeping the place hovering above freezing? Not sure I can afford to "finish" the job with studs/batting until the Spring...

 

[DC73]

Do yourself a favor and visit two websites: BuildingScience.com and GreenBuildingAdvisors.com Both have much information on the proper way to insulate various structures. The GBA has a good Q&A forum where you can post your questions to the experts.

DC