This is something I saw on a friend’s home. He has vinyl siding that is about 20yrs old and has discoloration that is 16" O.C. that follows the wall studs. I unzipped a section of the siding and confirmed that the discoloration lines up with the studs. The house is sheathed in an old USG black colored fiberboard with no house wrap. Could lack of house wrap have caused this discoloration? I have seen a lot of homes this age with no house wrap using this sheathing material and have never seen this patterned discoloration. Any ideas out there as to what may have caused this?
Moisture (condensation in this case) is the #1 cause of building deterioration.
Thanks for your input. In your opinion then, do you think that if a building wrap was used to control condensation then this would not have happened? The thermal bridging, I imagine would still happen even with building wrap since it is not an insulator.
building wrap is designed to keep moisture out of the building, and to let moisture in the building out. As you stated this would still happen even with building wrap.
It can also let vapour into the building envelope through a process called
“reverse vapour drive”.
Never heard of that before, would you mind elaborating a bit on it?