Crawlspace insulation – do I need to change my plan?
We converted an old closet in a bedroom by demoing it’s front wall and installing a header, creating a nook for a desk. Behind the nook WAS an unconditioned crawlspace, created at the junction of two opposing gables, and divided by a valley rafter. The walls of the crawlspace are brick on block and are very drafty.
Originally I prepped the area by installing vents from attic to the open area of the rafters, and filling the rafters and back wall of the closet with Roxul (R23 for the rafters, R15 for the 2×4 wall). Even though the rafters hit a valley rafter vs go down into a soffit, I figured that allowing air to pass from the unconditioned crawlspace to the attic was a good idea.
Because the crawlspace has a lot of room, we ended up deciding to open a small area in the room behind this room that faces the crawlspace. I attached polyiso to the walls and airsealed with foam. Then I stapled paper faced R21 FG inside all rafters, and taped to airseal. It is not airtight by any means, but much better than it was.
My question now is, now that this crawlspace is insulated, what should I do with the vent channels that were already installed? It will be hard to yank them all out w/o disturbing the Roxul (I’ll have to pull down the FG a bit but I can reattach/retape) but I am afraid that cold air will pass down from the attic into the space and end up – if pulling them out makes a difference I can do so.
I attached an extremely crude pic that leaves out a lot of detail. – for instance it leaves out the valley rafter entirely, but hopefully you get the general idea… I am worried about the crawlspace and the “enter here” door getting colder than necessary because of the channels.
If that makes sense, thanks for any advice!
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