Is the delaminating plywood FRT? There was a new roof installed and only about 25% of the original sheathind was removed. It appeared that they installed the plywood over the 75% of the other sheathing that may be FRT.
I know the origianl sheathing is a bitch to remove as it breaks into little pieces.
Thanks
Dave
Dave,
You should see a manufacturers stamp on each sheet if it was.
Assuming it was an attached dwelling, the FRT would usually run 4’ and 8’ alternating in from the partition wall.
I can’t imagine many of the bad batches of FRT plywood are still installed, but there are always surprises.
Most of the FRT I’ve seen has a whitewash look to the surface and every sheet is cleary stamped.
Even when I installed reg. ply and used FRT coatings I had to have a stamp made and label every sheet before we could get the final and CO.
What is “FRT” by the way?
http://www.inspect-ny.com/structure/FRTplywood.htm or it can also be the affliction caused by copious legume consumption.
Hi Dave,
the color of that sheathing combined with its delamnation does sound like FRT, as other have said it should be marked, but when it degrades the label cannot be seen.
Was this on a condo or townhouse with common party walls? also when was it built?
Regards
Gerry
Gerry
The home was built in 1946. It is a single family ranch home. My accross the street neighbor has the same sheathing as I remember last year when it took him days to tear off a small area of the sheathing as it breaks into little pieces and doesnt remove like plywood or flakeboard.
Thanks for the replyies mates
Dave
Hi Dave,
I very much doubt that that is in fact FRT, FRT would normally only be used on property such as condos and town houses where fire protection is required for the roof decking 4 feet either side of a party wall, also FRT was not used before the late 1970’s.
I believe that what you were looking at was just older moisture damaged plywood which had darkened due to age, damp, and airborne contaminents.
Regards
Gerry
I’m with Gerry. I used to see FRT all of the time, and have never seen it on a single family home. It is more expensive, and even if the 40’s roof was re sheathed in the 70’s it is very doubtful the roofing contractor would have spent more money for a sheathing that was not required.
Moisture damage and age is your culprit here.
Gerry and Blaine … I second that notion … 