Defect ID


Can anyone tell me what might be going on with these shingles? I have not seen this type of damage before.

The roof was installed in 2009. It’s a barn (gambrel) style roof. The pattern is at the sealing strip, and is on about 2/3 of shingles on the south and west, some on the east and north as well, but not as pronounced.

Infrared at the interior showed good insulation. I was not able to get into the upper attic to actually view. I have no idea what the ventilation was like. Just some passive vents in the upper roof.

I can see heat being an issue, but shingles shouldn’t fail like this even if they get hot should they? Ice damming is a bigger problem up here than overheating generally!

Thanks for any help you can give.

Possibly damaged / dropped while in the bundle, but it looks more like a manufacturing defect to me. Was the affected area greater than a single bundle of shingles?

That’s what I thought when I first saw it, but it is too extensive for that.
It’s about 2/3 of the observed shingles on the south facing roof, some on the east side and the garage as well. There was no access to the north on the house so I couldn’t see what was going on up there.

I have advised the client that they should check with the owner to see if they still have receipts and could transfer the warranty. No way is this roof going to last to it’s expected lifespan.
It’s just weird it’s happening at the seal strip. I would have expected it to not flex there at all. That and the patch of wear is typically about 1/2" wide.

Almost looks like the sealant strip partially bonded while they were stacked. Were they fully bonded? If the sealant strip had granules embedded in it I would expect a weak bond.

Yes, they were fully bonded on the ones I tested where the defect was most pronounced. Didn’t see any more granules than usual in the bonding strip of the couple that I pried up a corner on.
I’m wondering if it was too hard a bond, and when the shingle expanded in the heat it caused compression at the strip and pushed the granules off. That’s a long shot though!:wha?:
Another thing that has been suggested is blistering, again, potentially caused by the strip.
I wrote it up as a potential manufacturers defect. The seller (a realtor) owns the house as a rental and put the roof on, so she may have receipts. They could get the warranty transferred and file a claim. Then we would find out what it was perhaps!
None of the roofers in town that I have shared the pics with know what’s going on with this roof.
It would seem no one here knows either!
One of life’s little mysteries I guess!
Thanks for your comments Kenton.

I would say manufacturer defect. Possibly a roller too tight on the production run. It doesn’t show on the laminated tabs, so I doubt it is a stacking problem.