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Delamination from wind?


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I was called to inspect a roof for hail damage that had been denied by adjuster. When I climbed up on the roof, I noticed dozens of torn through adhesive spots, mostly toward the corners of the tabs.

The adjuster says "The rips are indicative of roof sheathing movement due to inadequate ventilation of the roof or improper spacing of the roof sheathing and not related to wind or hail"

However, roof is ventilated correctly and there are no leaks on the roof (yet). Nothing notable in the attic.

A storm with 60+ MPH wind gusts and hail had moved through the area and damaged most of the homes in the neighborhood.

I'm guessing severe delamination and the sealant bonds are just really strong?

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It looks like whoever did that roof hand-sealed those shingles against wind lift and tearoff and apparently did a good job.

OT - OF!!!

M.

Only if the shingle is creased along it's upper exposed edge where the wind would have bent it had it come loose. If there's no accompanying crease of that type then it could be structural movement of the roof deck instead.

Marc

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The sheathing moves how far? Enough to tear the nails out of a bunch of shingles?

There would have to be some serious structural flaws for that scenario. So is the insurance guy saying the shingles stayed stationary while the sheathing dropped? [:-party]

The shingles appear to have a weak bond between the layers.

The wind may not have folded the shingles back enough to crease them, but tore them loose.

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If the deck moved, wouldn't I see other signs of damage, or even deformation? How much movement would it take to tear a hole out from a shingle?

I've never seen anything like this.

Also, his back yard is a wide open golf course. The winds came in from that direction, and there are many creased shingles on the roof.

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Marc,

I disagree. The purpose of hand sealing is to prevent the wind folding the shingles back. If the wind was enough to cause the shingles to pull at the adhesive enough to start tearing the shingle below, but not enough to completely pull the shingle loose, fold it back and cause the crease you mention, then the hand sealing did it's job. Sure, the roof is damaged now but it didn't come completely off with the wind and so the homeowner didn't have the kinds of water damage to the attic insulation, ceilings and personal property that he would have had if the whole thing had been peeled off like an onion skin.

ONE TEAM - ONE FIGHT!!!

Mike

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I've seen one incident where a new roof was installed on a house with a foundation issue. The foundation repair involved jacking up a portion of it and followed the installation of the new roof by a couple months. The damage to the shingles was such that they had to be replaced on at least two large roof surfaces.

I've also seen interior drywall finish crack from excessive movement of the walls. This was in New Orleans following hurricane Katrina in 05'.

It's unusual, yes.

Marc

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Marc,

I disagree. The purpose of hand sealing is to prevent the wind folding the shingles back. If the wind was enough to cause the shingles to pull at the adhesive enough to start tearing the shingle below, but not enough to completely pull the shingle loose, fold it back and cause the crease you mention, then the hand sealing did it's job. Sure, the roof is damaged now but it didn't come completely off with the wind and so the homeowner didn't have the kinds of water damage to the attic insulation, ceilings and personal property that he would have had if the whole thing had been peeled off like an onion skin.

ONE TEAM - ONE FIGHT!!!

Mike

My experience is that there is unlikely to be a point where an adhesive begins to come loose but holds. Once it even begin to fail, failure is imminent. That's just my experience. It's not from anything I've read.

A shingle covering rendered unable to tolerate lateral movement because of DIY adhesive dabs or for whatever reason will fail at the adhesive junctions without the tell-tale horizontal creases. That seems to be what's happened in this case.

There's a downside to DIY adhesive dabs but in hurricane country the advantages outweigh the downside.

Of course, this all just my opinion.

Marc

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Heck,

We see drywall cracks due to movement all the time out here. Most of the time, when lumber gets to a site back east it's had weeks to dry. By then it's warped a lot and it's easy to cull the hooked stuff and toss it on another pile for the lumber yard to sell out front to the unsuspecting do-it-yourselfer.

Out here, despite it supposedly being kiln dried, the wood sits around in a damp environment, absorbs more moisture and swells. Then builders here work year round, rain or dry, and use just about all of it because it's still pretty straight. Then, over the course of that first year after the house is dried in, the lumber shrinks, the house loses height and there are cracks everywhere.

I've done new home inspections where we'd marked every drywall flaw for the builder to repair, the builder came in and repaired them, and then when we came back a year later for the first year inspection there were as many, if not more, cracks, doors out of square, doors that bind, etc., due to lumber shrinkage. Sometimes a wall stud will hook so badly that first year that when we come back we find big ugly humps on interior or exterior walls.

Oh well, that's the bad news. The good news is that by making a new homeowner aware that it will happen during the first inspection I'm just about guaranteed to get the call ten months later to come back and do the first year because by then the homeowner has started seeing that my prediction is coming true and needs to get all of that documented.

Never see roofs damaged due to expansion/contraction though. Maybe that's because they use OSB or plywood and that stuff is more stabile than plain lumber. I have seen lots of roofs damaged by wind though. It seems like 99 out of a 100 roofers here don't know what a drip edge is and 999 out of a 1000 here don't bother to hand seal the shingles when they install roofs between mid October and mid April when it's still too cold for the adhesive strip to activate.

I once arrived at a house in mid-November about twenty minutes early. I had a 12-inch sub with me, so I sat there and ate my sandwich while I ate. The homeowner knew that his roof was shot; so, to beat me to the punch he'd hired a roofing company to strip the roof to the deck and re-roof. As I pulled up, that crew of four was just starting at the eaves on one side of that simple cape. By the time I finished my sandwich and the client arrived, they had reached the peak and were working on the other side. By the time I finished going over the contract with the client they were almost done. By the time I'd finished my first turn around the outside, they'd cleaned up and were gone. No drip edging, no hand sealing (it was November), nails all power driven and most of them over-driven and lots driven in at an angle. Flashings gooped to chimney instead of being cut in, etc..

I got to write up a bunch of stuff that day. Two days later the owner of the roofing company, who spoke perfect english and sounded like he'd grown up in America, called me up to express his displeasure with what I'd written (S'funny, not a single person on that crew was speaking english. Not sure what they were speaking but it was clearly not spanish, french, german or korean.).

While he was on the phone, I asked if he had access to the internet. He did. I asked him what brand and series of shingle they were. He told me. Then I had him follow me on the net as I found the installation instructions for that brand and read off the little blurb that talks about hand sealing the cover when in a high wind area or when the weather is too cold to activate the adhesive strip. He hung up after calling me a f*****g dick.

I never got the chance to thank him for the compliment.

It might be expansion/contraction damage; but I think it's wind damage that could have been a whole lot worse if those shingles hadn't been hand sealed.

ONE TEAM - ONE FIGHT!!!

Mike

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Thanks for the insight guys. I snipped one of the photos included in the adjusters report of an area with the tearing and tried to make the sheeting position fit the damage. It doesn't even come close to matching up. How would there be tearing in the middle of a sheet if the the decking did move?

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It doesn't even come close to matching up. How would there be tearing in the middle of a sheet if the the decking did move?

The adhesive on the shingles makes them, as a whole, less tolerant of movement than the nailed decking. It's sort of like brick veneer on a monolithic concrete foundation. You can gauge how much differential movement has occurred in the foundation by examining cracks, or the lack of them, in the veneer. Portland based mortar is very intolerant of movement. That's something I learned at the University of TIJ.

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I don't recognize any dominant pattern in the photo. I see no basis for any one particular cause of the tearing, only a basis for a carcophony of causes.

Looks like I'm not helping your case.

Marc

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Thanks Marc. Your analysis is greatly appreciated. I will have to take a closer look at the home's foundation and look for any other signs of movement.

I've been wrong more times than I would like to admit identifying causes of damage to roofs, but I've learned something new every time.

In this case, I assumed wind, because it seemed like the most likely explanation considering the abundance of supporting evidence.

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If this roof surface is the only one damaged and faces Lake St.Clair, you may have a case for wind damage. Your exposure rating could be Category 'C' on the eastern side and 'B' on the western side if the house is within 1,500' of the lake. Cat 'C' raises the wind velocity felt by about 20 mph above that of the Cat 'B' side.

Marc

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Wind or hail it should be covered by the owners insurance. I went though a dozen+ cases like this with Katrina and folks fighting their insurance providers, one threatened with litigation they usually paid the claims. Most were due to the adjusters who are also paid a bonus based on the amount of the claims that are paid or not paid! A little known fact when it comes to the world of insurance.

Also 3-tab shingles are not rated for high wind areas!! Many times folks forget this little tidbit..

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Clearly the shingles were hand sealed.

I suspect that the hand sealing simply glued the shingles together too well, to the point where there's little ability for them to expand and contract with normal heating and cooling cycles. Over time, they tear at the corners, often in a stairstep pattern.

Nothing in any of the pictures looks even remotely like wind damage.

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Here are some photos of other areas of the same slope. These rips are everywhere on the south slope. I didn't find any on the north facing slope. I also counted over 30 creased tabs on the south slope, but now I'm beginning to wonder if they are wind related at all.

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Here are some photos of other areas of the same slope. These rips are everywhere on the south slope. I didn't find any on the north facing slope. I also counted over 30 creased tabs on the south slope, but now I'm beginning to wonder if they are wind related at all.

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Now, *those* pictures show wind damage. And from the looks of it, the damaged tabs weren't hand sealed.

Also, the fact that the "rips" are on the south side bolsters my opinion that you've got thermal tearing on that side.

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  • 5 weeks later...

Consider hiring your own inspector to assess the damage...use someone independent - not a roofing contractor. You might consider a home inspector or engineer. If their report indicates wind damage, then you can build a case for replacement...and the squeaky wheel gets the grease...

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Consider hiring your own inspector to assess the damage...use someone independent - not a roofing contractor. You might consider a home inspector or engineer. If their report indicates wind damage, then you can build a case for replacement...and the squeaky wheel gets the grease...

I think the OP is a HI.

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