** Roof Deck in question


Having the house re roofed. Does this need to be replaced? Also if not is there any way to treat the mold.



From that PIC it appears your eave vents may be blocked by insulation.

If the sheathing is in otherwise good condition, instead of replacing the sheathing, there are options for cleaning it… here’s a link to a pretty cool process (pun intended)… http://www.diamonddryiceblasting.com/dryicecleaninguses_moldremed.php

Google “dry ice blasting” for contractors in your area.


Improve ventilation by adding more roof vents and, as Nick suggests, clear insulation from the soffit vents (add vent baffles), seal the attic hatch with weather stripping and you should be good to go.

The staining might be mold but in might not be, unless you have had it tested at a lab you don’t really know. Removing it is VERY expensive.


I find this situation quite a bit and it’s caused from ventilation issues. Nick pointed it out already.

Recommend having the mold cleaned and then recommend proper ventilation. I always give my clients (with ventilation issues) this link.

I occaisionally find what looks like mold in an attic where the ventillation looks great. Yesterday’s inspection was a great example. The home had a continuous ridge vent and lots of venting at the eaves (three 2.5" screened holes per truss bay). None of the vents were blocked. No vents terminated in the attic. There had been a roof leak, but it was on the other side of the attic.

Paul, just curious, are the structures where you find that condition newer buildings? the reason i ask is that i have seen on numerous occassions when the sheathing had mold growth coming from the supplier especially during the rainy season (june - october ). with no other apparent explanation is that a possibility?

Usually it is in older home. 60’s and 70’s vintage. This one is a 2001 though.