Insulation and Moisture Control With Gapped Wood-Plank Sheathing
Hey all, I’m currently renovating a 1949 story and a half house in central Ohio and for the first the first time during the project I’m completely stumped. I feel way over and under informed a the same time after reading everything things I can find about insulation for the past three weeks.
After taking down the old sheet rock in the kitchen, I noticed that the plank sheathing of the house isn’t tongue and groove. Most of the planks have and eight of an inch gap between them, some a quarter of an inch. Behind the planks you can see a black felt house wrap, maybe tar paper.
Should I fill these gaps before adding insulation? Should I add insulation at all?
The outside of the house is cedar shake siding and from the interior there’s a couple of spots where it looks like water has gotten behind the sheathing, but really not that much for a seven decades old house.
My concern, spurred by dozens of internet articles, is that moisture will get behind the planks get trapped by the insulation and cause mold and damage.
My current plan is to put spacers between the rockwool and the sheathing (maybe like the air chutes you use in attics), leave the gaps open so that moisture can leave and cover the rockwool with aquabar Kraft paper as a vapor retarder.
Unfortunately the membrain product that is always recommended here appears to be unavailable to the point that I can’t tell if it’s produced any more.
My main question is whether it would be better for me to go through and fill the gaps to try to prevent moisture from getting in in the first place or to leave them open so that the moisture can escape.
OR, is it not even worth insulating? The house has stood for 70 years being able to dry itself out maybe it’s best not to mess with it.
Thanks in advance! There’s such an absurd amount of insulation information and opinions out there, it’s hard enough to figure out what’s suitable for your climate let alone a less typical building structure.
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