2 Layers of sheathing?? - InspectionNews

Paul Kondzich · #1 (**permalink**) 07-15-2008, 10:58 PM

I have not run into this before so I need some advise. This actually involves a good friend of mine. He does not have alot of money and I shot down their first deal last week after 10 minutes. So I get to this house built in 1960. I pulled in and thought cool, new roof. Did the whole house, its all good, major remodel in 2005. Walking on the roof it felt and looked good. So we saved the attic for last. First thing i notice is the plywood sheathing is delaminating....everywhere. Its not like it got wet, it is simply delaminating. You could pull big sheets of it off like balsa wood. The problem is when they reroofed about 4 years ago they put new OSB over the old plywood. There is sheet metal screw everywhere screwing the new OSB into the old plywood. Of course it is unknown if any of the screws actually hit any trusses. The sellers realtor is bringing in a contractor, and a roofer tomorrow for an evaluation.

In my limited knowledge of roofing I would assume that as the original plywood continues to disintegrate it will leave a gap between the trusses and OSB. Who knoows how long this could take??

Anyway before my phone starts ringing tomorrow...any advise. In my opinion the only fix to make this correct is ripping the roof off, including the old bad sheathing and starting over.
Am I overreacting here??

Also was the plywood in 1960 defective. The attic was well vented with gable vents, so I dont think it is a heat issue.

Brandon Whitmore · #2 (**permalink**) 07-15-2008, 11:14 PM

If there were never any ventilation or moisture issues, I doubt that the sheathing would have delaminated like that. The old plywood was likely 3 ply which is crap. Poor ventilation from a past roof along with 3 ply equals that delamination. I am replacing a roof right now built in 1982 and the 3 ply is delaminated pretty heavily.

Based on the pictures alone, I don't know what to say. Skinning over old sheathing does occur, but I have never seen someone skin over plywood in that condition. Will it work as installed? MAYBE It would not have been too much more work to just rip that sheathing off and start over with new sheathing..... whoever did that should be stoned (alright, that may be a little harsh).

I would say you made the right call recommending an expert take a look at it.