Going to re-side my own house with FC siding. The house is skinned in plywood Reverse B&B with asphalt impregnated board underneath (Celotex). Would it be useless to re-cover with housewrap or felt after taking off the plywood?
Just wondering how tight the Celotex is in respect to moisture and wind. I suspect I could mastic the joints with tar or something similar, but is it worth it?
This is central Illinois and air definitely passes through on a cold windy day.
Thanks from the tinknocker side of the room!
Replies
When we resided we applied Tyvek (taped at all seams and around windows/doors) over our fiberboard sheathing. It made a remarkable difference in the amount of air infiltration -- from strong drafts out of wall outlets to no detectable drafts. I can't say that it definitely saves energy, but it does make the house much more comfortable on a cold day.
Thanks, my concern was using felt paper over something already impregnated with asphalt. We have definite air infiltration in the winter. Every outlet on a exterior wall shows good air movement. Tyvek should stop that.
Sure hate to remove the plywood siding, but it's been left unattended by the previous owners for so long that it would be a struggle to get the FC to lay flat.
Instead of assuming that you can prevent the infiltration with a house wrap, you should first determine where that airflow is coming from. There are half a dozen good candidates other than or in addition to the sheathing. Highest on the list is penetrations like holes drilled in top and bottom plates for the electrical and plumbing runs. A few cans of spray foam in the right places will pay for themselves pretty quick in a house like yours
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Eliminating air infiltration with housewrap isn't an "assumption" -- I can attest that it's a FACT in our 1976 conventional construction home in southern MN.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
How much of his infiltration will the housewrap eliminate if he has 1-1/2" holes in his bottom plates?
Five percent?
Ten percent?Whooeee!I think you skipped over the point I was making - not that housewrap is unworthy, but that if you have a problem, you should identify the source of that problem and fix it first.Otherwise you would be like the housekeeper who is mopping up the water spilling on the floor without turning off the faucet that is causing the kitchen sink to overflow
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Well, depends on what the bottom plates are sitting on, I suppose. The only holes in my bottom plates are the bolt holes.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
Agreed. I had the foundation (block) foamed up to the top edge of the rim joist inside of the crawl space and that was significant. Now I believe most of the air leakage is coming from the joints and possibly the condition of the Celotex.
The house was built in 1972, but overall is in pretty good shape. The vertical siding is the only real sign of neglect.
It just seems contrary to wrap a material such as Celotex, although I can see the obvious benefit.