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Discussion Starter · #1 ·
we shingled a roof, 12/12 O C shingles last october. Now the

shingles are buckeling in different spots on the roof.

Ridgevent installed.

Synthetic paper, ice and water all installed flat.

The buckling in on the in on the papered parts, but only over the

home, not the porch overhangs or the soffit overhang.

Also there isnt any sign of buckling on the 6/12 parts of the roof.

Now, the 6/12 has blown insulation and the 12/12 has been spray

foamed tight to the osb. Parallel trusses, the insul is like 15" thick.

I dont know why we even installed ridgevents.

Now my 1st thought was because of the foam and not having

ventilation, the roof gets way to hot and moisture cant escape

causing the shingles to buckle.


Any one else ever have this happen?


Thanks,
Bill
 

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I'm curious what you find out. I am on a remodel now that we had spray foam installed between the rafters. They filled the cavity all the way to the osb. This is the first time I've had a job foamed.
 

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I'd think that an unvented roof sprayed with open cell foam could allow moisture laden warm air to rise and permeate the foam, condensing on the roof sheathing.

After the heating season, the constantly damp sheathing would heat up and water vapor would be moving mostly upward toward the shingles?

I might be slightly off with this but I'd imagine the aftermarket sealed roof system was never done properly for the climate/conditions.
 

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I didn't realize you were in Florida. In that case, you wouldn't have furnace conditioned air condensing, but possibly moisture trapped from another source.

They may have bath or hood fan venting into the attic or eave/soffit vents open that allow humid air in and with ridge vents sealed, it's not able to escape properly.
 

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If the areas are small, just go up and remove the affected shingles.

You can then see if there is anything under them causing them to buckle. There is a chance the underlayment is the issue. This often won't be noticed until the newly installed shingles have had a few days to settled. It used to be a much bigger problem with organic felt and 3 tab shingles, but it still can happen with synthetic and laminates.

It's possible that there is another issue with the roof deck, but you won't know unless you remove the shingles.

I would venture that just removing and reinstalling the shingles, coupled with a slice in any wrinkled felt would eliminate the issue permanently.
 

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Wouldn't matter if spray foam was sprayed on the roof sheathing. It may help the attic, but not the roof.
convection needs to draw air so it very well may be part of the problem.
figure 140 + degree attic holding some of that temp thru the night , outside temps drop.....Foam is a good insulator but will be the same temp as its surrounding . Id fix the ventilation issues as well as look a the actual deck, like others said it can be a few different things.

I have often wondered if foaming the sheathing doesn't actually raise the deck , underlay and shinge temps on a warm sunny day since the foam is blocking the radiant heat from going into the attic . Seams to me the heat would build hotter and hotter on the decking and shingles. Thats just my thoughts tho and since I haven't done anything shingled in over 15 years I may be way off

I do know foaming an open perlin metal roof works like a champ, the metal reflects heat and is not much for storage
 

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Discussion Starter · #19 ·
it was on both. OC oakridge shingles. we checked the osb under the paper and it looked like new.

i know we didnt shingle over a wrinkle in the paper or ice and water. the problems are mostly over the 4" seams in the osb. the osb still had gaps for expansion and we used h-clips
 

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Had something like this happen a couple years ago on a tear off.

The customer spent 6 months researching how to property insulate his older home with knee walls. After many phone calls and emails on my opinion he decided we would tear off the old shingles help him and his friend pull the 1in deck boards and he would remove all the old insulation. Pink foam insulation was then cut and laid between the rafters and he used the great stuff to fill any cracks. What was left was about a 1 inch air space so he achieved some 2.5-3 inches of insulation. His trusses were basically 2x4's.

We put the old deck boards back on and then put 7/16in OSB over the whole thing (insurance job). The work was completed late Summer. The next Spring he called to let me know the shingles were buckling. We took a bunch of pics and after removing the buckled shingles found the buckling to have occurred at the felt paper seams. Felt paper used with the CT Roofer Select felt. Originally I contacted my CT rep and told him his big buck felt had bubbled and he said he'd pay for repairs. After discovering it wasn't the felt that caused the issue never sent him a bill. We put on two rows of ice and water shield and every felt overlap bubbled but only on the North side. Good news was we were able to carefully loosen and nail the shingles back down without damage. Did the repairs for free... 3-4 years later no issue.

On another job a year or two prior did a 40sq addition (yes 40sq addition) on a reservation house. Some of the roof was 12/12 which got spray foam insulation directly to the underside of the 7/16 OSB. The home owner noticed wavy shingles and upon inspection found the decking to have pulled in an inch or two and some of the sheathing staples to have pushed up the shingles along the trusses. I put a bid in with Xactimate and never did the work (fine by me). Ended up being the spray foam at fault as it reacted with the OSB. Last I heard the insulation company went after the spray foam manufacturer for compensation.

My thoughts were the shingles would be easy to pull off the OSB but what would it be like pulling the OSB off the spray foam???

What I didn't understand was why they didn't try to put in baffles and let the roof breath? It was engineered as a hot roof as new construction, no soffit vents and no ridge or turtle vents.

Both sides of the roof were bad but worse on the North side which was gable to gable while the South side had a dormer run into it.
 
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