i have noticed on the TV show “Ask This Old House” that on the current project tom Silva is using felt on the outside walls in stead of Tyvek. He is only doing parts of the house where he is replacing shingles and such. Just wondering?
I think they are going to spray foam on the interior walls. Could that be the reason?
Replies
Certainly if you spray foam then an air barrier is unnecessary. And felt is easier to work with if you're just doing parts of a wall.
And, though I've never hung shingle siding, I'd imagine that felt is easier to work over -- provides some "traction" when you're holding shingles against it.
Cedar tannin is destructive to tyvek and the like.
As an architect who has seen Tyvek degradation first-hand, I don't allow it on any projects. Only felt.
Degraded Felt Paper
Speaking of degradation, what would cause felt paper to degrade?
We have a 30 year old house with braced 2x4 exterior construction with no exterior sheating, felt paper over the studs and cedar clapboard siding.
While remodeling our bathroom & downstairs basement (which share the same exterior wall) we have discovered the felt paper to be in really bad shape. its torn and crumbling everywhere and appers very thin.
Thanks
Ryan
in your case, heat caused it. UV or moisture can, but neither very likely under the siding.
As Dan says, it could also be poor quality paper. Thirty years ago was when they started reducing the amt of asphalt used in tarpaper in response to escalating oil ccosts and the "oil crisis"
Some makers did not do that very well. I was sent some made in Mexico that I had to reject right off the truck it was so bad
in your case, heat caused it. UV or moisture can, but neither very likely under the siding.
As Dan says, it could also be poor quality paper. Thirty years ago was when they started reducing the amt of asphalt used in tarpaper in response to escalating oil ccosts and the "oil crisis"
Some makers did not do that very well. I was sent some made in Mexico that I had to reject right off the truck it was so bad
Thank You
Thank you both for your responses.
So since heat seems to be the culprit, do you think it would be from the exterior or interior (or both). The wall is south facing and gets a good deal of exposure.
Hoping to remedy this problem next spring by installing new 30lb felt and 1 or 2" foam board over the studs as well as new interior insulation.
On a south exposure I would guess that temps at the paper could reach 120 or so on a warm day. Enough to bake tar felt pretty well.