vinyl siding (cupping)
vinyl siding (cupping)
(OP)
Looking for a cause of the cupping in the siding at the inside corner (double J-channel), please see attached pics (cupping marked with chalk). I have ruled out heat-related damage, this is under a covered porch and no neighboring windows within hundreds of yards. Also no grill nearby.
The siding panels are approximately 8 inches long. When I shifted the siding to one side, an approximate 1-inch end clearance is at the single-piece siding runs. Tight nailing of the fasteners is not an issue as I can slide the pieces of siding back and forth with ease. Bottom edges of the siding panels are not popped loose, suggesting that there is a sufficient allowance for thermal expansion at the end of the panels. The panels were not removed.
Is observed cupping a manufacturing defect, or something else? Siding about 10 years old.
Pics attached. Any assistance is much appreciated. Thanks.
The siding panels are approximately 8 inches long. When I shifted the siding to one side, an approximate 1-inch end clearance is at the single-piece siding runs. Tight nailing of the fasteners is not an issue as I can slide the pieces of siding back and forth with ease. Bottom edges of the siding panels are not popped loose, suggesting that there is a sufficient allowance for thermal expansion at the end of the panels. The panels were not removed.
Is observed cupping a manufacturing defect, or something else? Siding about 10 years old.
Pics attached. Any assistance is much appreciated. Thanks.






RE: vinyl siding (cupping)
RE: vinyl siding (cupping)
RE: vinyl siding (cupping)
RE: vinyl siding (cupping)
RE: vinyl siding (cupping)
Based on my experience, I would say that it's a manufacturer's defect.
(BTW, got my house completely re-sided in the claim.)
RE: vinyl siding (cupping)
Opinion 1
The cause of this damage is heat distortion. This is caused when the material heats to a temperature too fast and expansion takes place causing the wavy buckling look. This can be caused by sunlight reflection or other heat sources. After seeing that one section is in a very short run and next to a door into the house, I suspect it was caused by a gas grill. If this can be proven incorrect, then look for reflection. The fact that the pieces are so small (siding pieces) and this has happened means that the heat had to be high.
Opinion 2
The course is very short so I would be surprised if it was expansion/contraction and, based on comment, looks like they left room for expansion/contraction (based on the picture).
I agree with Opinion 1. It looks like heat distortion and, because of the direction, looks like more grill damage.
www.PeirceEngineering.com
RE: vinyl siding (cupping)
Dik
RE: vinyl siding (cupping)
www.PeirceEngineering.com
RE: vinyl siding (cupping)
Dik
RE: vinyl siding (cupping)
www.PeirceEngineering.com