Asphalt shingle cracking

Observed a roof this morning where most of the shingles had cracking through out. The roof is only 5-7 years and there are 2 layers.

Is this a defect in the shingle? What causes this cracking? It is hard to see in the pictures all the small cracks iat the shingles.

I recommend having a roofer evaluate.

They also did a lousy job of attaching the patio cover.



The roof is only 5-7 years and there are 2 layers…

heat?? how is the attic ventilation ???

Looks like a Certain Teed Horizon Shangle Roof.

Cracking is indicative of a manufacturing defect.


The ventilation was marginal at best and the insulation was poor. (Only R 13)
I am sure the attic gets very warm.

I would agree that theses shingles are defective.



The shingles may have been defective before installation.

Erol Kartal

If this roof is only 5-7 years old, you’ve got a warranty issue.

and there are 2 layers.

would that not void the warranty ??


The roof appears to be a Certain Teed Horizon. I have found this cracking and blistering to be common with this roof. Most roofers are familiar with this problem and should be able to help with warranty coverage.

Check with the Roofing Distributors in your area. They may be able to have a factory representative look at the roof.

manufacturers defect or ventilation issue

i think the warrenty will likely be cut in half by most manufacurers when layers are doubled. but if you ever had to try and get any warrenty covered on a roof, it’s easier to part the red sea. not only that, but that roof was not installed properly at all. i can see all the black areas that are supposed to be covered by the following score of shingles. i think the warrenty will already be void due to improper installation, but maybe they’ll never check.

I think every manufacturer out there would also consider roof over roof to be improper installation and would void the warranty. I could be wrong, though. And if I am, just don’t tell my employees that I was ever wrong, please. :smiley:


The black lines you see are part of the shingle design. It is not necessarily an installation defect.

No sweat Russ. ship me some margaritas and i’ll keep quiet.:smiley: :mrgreen:
i only say the “cut in half” part 'cuz it happened to my neighbor about 10 years ago. and all the fighting in court wasn’t even worth the prorated 12% refund he got. oh well. cheers

Joe. i’ve seen those lines on archatectural shingles like in your link before, but i always thought that that was the part to cover up on regular 3 tab. i dought the overlab requirements are met in the methode shown in the pic. but i’ve been wrong before…no wait…i wasn’t.:mrgreen:

I also have concerns with the exposed - overlap areas, and roof slope. Not to mention it looks like an inferior installation. The warranty issue may even go back to the manufacturer’s specs’ - do they warrant their materials over a questionable substrate? Another issue may be “power stapling” is bad for this type of shingle.