Delaminating Roof sheathing

I inspected 49 year old home 1300 sq foot home with a realatively new roof. In the attic the roof sheathing appears to be delaminating and some staining was observed. The attic was vented by soffit and a ridge vents. The soffits didn’t appear to be congested with insulation, however the ridge vent had a filter in place. When I walked on the roof it was a little spongey. What comment would you make on this situation? Should additional ventelation be added?

Larry, Roof trusses were invented in 1952 and late 60’s before national use. You are saying this was a 1964 build.

This looks like an earlier build.

I have seen this type of delamination and was caused by a bad batch of plywood or defective from the Manufacturer.
Mostly in the mid 70’s that I have seen that.

Might have been a new roof covering, but the cut out for the ridge vent looks original to the build. Not common to a 1964 home.

Correct me if I am wrong. :slight_smile:

Thanks Marcel. Tax records indicate that it was built in 1964. Maybe it had a reconstructed roof structure after being built.?

Larry
http://www.fireengineering.com/articles/2011/11/havel-delaminated-plywood.html

Thanks Barry.

Good reading Barry. Thank you sir.

It would seem like you have attic mold due to poor ventilation. Is there enough insulation? If the roof is close to needing to be done, recommend that the sheathing be ripped off and replaced. Otherwise, the venting will need to increased and a mold remediation will need to happen. I am a mold remediation specialist and have done about 40 attics this summer. I see it all of the time. Attic mold is always more of a structural issue than it ever is an environmental issue.

In some areas, homes built during the 60s were sheathed with 3/8" plywood.