Exterior insulation too thin?
Azy_lazy
| Posted in Energy Efficiency and Durability on
Hi there! First-time poster. I recently bought a home built in 1980. The previous owner added a layer of 0.5″ foil-faced foam board insulation (foil facing inward) on the exterior—installed between the sheathing and the vinyl siding. There’s almost house wrap directly over the sheathing.
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Replies
What type of foil faced foam? Some is quite permeable.
This Is a wild guess I think they installed vinyl siding of the original siding.
The foam was never intended to insulate the house. They required a flat surface to install the vinyl on and the foam is the lowest cost way to get the flat surface.
When they did the same thing to my old 50s house the foam never became a problem even after I had the empty wall cavities blown full of cellulose. I think mostly because it is only R3 to begin with and then they put 1 or 2 nails in every square foot making it more or less R zero.
If my guess is correct about residing it is very important that you check the caulking joints that surround every window annually and caulk any opening as this caulking is the only thing keeping water out of your walls
Walta
https://www.greenbuildingadvisor.com/question/exterior-insulation-too-thin