What cause this damage and what is the name of this shingle

Hi Guys,

I just get into this situation. More than 60% of the roof has this crack line on the shingle but only 30% of them can be easily lift up. The rest is still bonding very well. At first i thought it is a wind damage but if it is wind damage probably you can easily lift up the shingle. How can we claim with the insurance?

Also, i know this some kind of collection shingle but dont know what brand and name. Any one have any idea?

Thank you so much

I recently saw this on a few shingles. I don’t have any real explanation but really interested in hearing what others will say.

I thought maybe it was due to how the shingles were handled during installation.

Looks like blistering and perhaps some solar cracking to me. Not an insurance claim. Might be from somewhat defective single, might be related to poor or improper ventilation.

Definitely a defective shingle. Tamko had a lot of problems with horizontal cracking like this, mostly on their heavier shingles.

I was thinking the same way you guys does but it happened on 80% of the roof surface and this roof is about 32 square. It is impossible to have 25 square defective shingle. Beside this is not a regular architecture shingle, this is collection architecture shingle which can be claim for 35-40 years shingle and they are about double the price of regular architecture shingle.

It cannot be damaged by the sun either cause we are in TX and if the sun can damage the Also have shingle the building code would require to have tile shingle installed.

I believe it cause by natural disaster and would be able to claim with the insurance. I just don’t know which can cause this and hope some one that have experience with this.

I was looking scroll down to look for your reply. Do you think of any other things that can be a reason for this? This house was on fire damage 10 yrs ago and they had to reframe the whole roof. These type of shingle was installed 5 years ago. It happened on 80% of the roof surface along with hail damages and wind damages. However, neither hail damages nor wind damages can be enough to full fill the full roof replacement. Only this damage can be. From my opinion, this roof need to be replaced because these crack line may create ice damper In the winter and the roof will be leaking.

I suppose if they didn’t properly install the decking and include clips, settling could cause some splitting. But unlikely over the entire roof.

You believe it is caused by a natural disaster? I think what you really mean is you want to see if you can figure out a hazard covered by the insurance that could explain the damage? How can you believe it is caused by a natural disaster when you frankly have no idea what caused it as you can’t even name the natural disaster (the proper term is covered hazard or storm event) you believe caused it. Based on the one mediocre photo you supplied, it appears to be a manufacturer’s defect. I looked at damage from thousands of roofs and have not seen any storm events cause what you are seeing. Has there been a recent hail storm in the area? Perhaps you could get a generous or stupid adjuster to buy it for hail.


Yeah, there was like 2 hail storm and 1 big tornado storm com across. Basically, I just try figure out what cause it. Because the sheathing is fine, really steady when you walk on it the whole roof, there are no bump or any sign showing of the improperly installation. I have seen this before as well on the couple pieces of shingle but not almost entire roof.

Nothing is impossible and as I stated, a lot of the horizontal cracking defect I’ve seen has been on the heavier shingles, like you’re referring to. Defect on thinner architectural seems to be mostly granule loss, at least in our area.


This is the type shingle $54 dollar per bundle and only cover 20 sqft

Manufactuer defect for sure.
It’s a fine cracking.
It cracked while it sat there.

If it would have been from wind,
It would Have been a rip or a fold.
This is nothing like that.

Look close.
Its like the moving ground of an erupting volcano.


I saw this on a house recently hit by wind and hail but it was only a couple of shingles, not the whole roof.

I’m going with manufacturer defect. Hard to reason on much else.

In my opinion the cracking is being caused by expansion and contraction from probably poor ventilation. You see the crack is just above the seal strip as a shingle expands that Seal strip holds down the end of the shingle and it can’t move if it expands and contracts enough overtime it cracks the shingle just above the seal strip. It’s not a natural disaster, it’s not wind damage, it’s probably not a manufactures defect I would bet, but just poor ventilation.

Sounds like something a manufacturer would say to get out of a warranty claim

Tamko Marathon or Iko 3 tabs. Lack of attic ventilation .
That happen after 14 years or more.
Time to put a new roof

That would be normal environment for a shingle, if it is cracking because of this it is defective.

Unventilated decks don’t cause shingle failure, lack of ventilation can cause other major issues but premature shingle failure is not one of them.

Really, so what exact Manufacturing defect would You say this is? Only possibility For defect would be the too aggressive seal strip, or alagatering if the asphalt that cracks the asphalt, not the glass may. But if that were the case one would expect to see a lot of failure on a lot of jobs in that same region from the same time. I believe the homeowner said that he was in Indiana. got to be a pretty good freeze thaw cycle in Indiana I bet.
Many Roofers (I am a roofer) have a tendency To call everything that isn’t storm damage a manufactures defect. Anything they can sell the owner on being able to get them a free, or partially free roof. It’s not always a manufacturing issue. The owner needs to investigate a little further in my opinion.

Kevin Pratt

Please excuse my abbreviated message sent via iPhone

I think All manufactures would disagree with you.

Kevin Pratt

Please excuse my abbreviated message sent via iPhone

Of course they will disagree, they invented the idea that a warm deck makes their shingles shrivel up & crack to blame it on the house instead of their defective shingles.

A shingle is in an environment where it is expected to undergo massive temperature changes in a cyclical manner, it needs to be designed to handle this which pretty much all of them are.

If this were indeed a problem we would see many more cracked and torn shingles than we do, the ones we do see are defective.


Well, we can agree to disagree. I still would like to know exactly what defect you believe it is? Too much asphalt, bad fiberglass mat?