Is Blown-in Insulation OK here?
This question concerns a wall in our garage/shop. The wall is cement block up to about 6 feet, and then 2×4-framed wall for 24″ above that. I want to insulate the wood part of the wall, and was considering using blown-in insulation, rather than having to rip off the interior boards to put in rolled insulation.
I have no idea what this blown-in insulation is designed for. Is there any reason not to use it for this situation? This is in the Northwest, so it is very wet most of the year, but the shop will be heated several days a week, so it should stay fairly dry inside. Don’t know what different types there are, but this stuff comes in a bag and I’ll rent a blower machine from the lumberyard to apply it.
forestgirl — you can take the girl out of the forest, but you can’t take the forest out of the girl 😉
Replies
I don't think you will gain anything by insulating only the top 24". Maybe a better plan would be to build a new wall against the old and properly insulate it. I know there probably isn't enough room for a new wall.
Hi Mark. I have some additional info, and questions about your comment. Questions first: Are you suggesting to build the new wall over the entire old wall (cement blocks and all)? I had been under the impression that cement blocks have a pretty good insulation factor. Wrong? Hmmmm.
The shop is built up against a small hill, so the cement wall is below grade, though most of the hill on the outside is cut away so earth doesn't actually touch the wall except for maybe the bottom 18-24".
Since the wood part of the wall is the part that sees some buffeting by wind as it comes across, that's why the insulation. And, I figure each bit of insulation helps.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Block do not offer much help with insulation. I was thinking something similar to his suggestion such as glue 1-1/2" foam to the whole wall and add furring over it using tapcon screws to fasten through to block then finished wall surface.Excellence is its own reward!
Well, I'm seeing what you mean. Found a chart of various R-values and the concrete block, filled no less, is listed at 1.93. What with the rainy season staring me down, and 3 major projects to get done right away, I'm going to have to live with what I have this year. Re-doing that wall is going to involve pulling out most of my workbench and pegboard. Next year. Thanks for putting that top 2 feet into perspective for me. forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
As a stopgap, maybe you could throw up foam board on just that top section. Temporarily tacked for futrure adjustments thenExcellence is its own reward!
I was thinking what piffin said. Stud wall floor to ceiling if you have room, foam and fur if not. Block has good thermal mass, but almost no insulation.