"Bubbles" under shingles?

Pacific northwest homeowner here.

Have lived in this home for 10 years, and our roof is approximately 20 yrs old. They are normal asphalt/composition shingles. The roof looks pretty good overall, IMHO. I am up there every week or two blowing off leaves/debris.

A few weeks ago, I noticed that what I would call “bubbles” are forming UNDER the shingles. We have a tri-level with a pitched roof and vaulted ceilings in certain areas, the bubbles are forming only over the vaulted ceiling of the living room, which faces northeast. (We do have another section of vaulted ceilings, but no bubbling over that section…)

One “bubble” is maybe one-and-a-half feet wide by six inches, one is maybe 6 inches by 6 inches. They are raised approximately 1.5 inches up from the rooftop beneath. If I step on them forcefully, they flatten out, then spring back up when I step off. It feels as though the plywood underneath is solid and has no give.

  1. What is causing this? Why is it happening now?
  2. I assume I need to repair it sooner than later? Is this something a handy homeowner could take on, or only a professional? If so, what would a rough cost estimate be?
  3. Or, would I need to get the who roof redone!?

(PS - I tried taking pictures, but it’s so subtle at this point - unless you’re walking on it - that the bubbles aren’t really very noticeable/visible in a pic…)

Thanks!

Sounds like a case of plywood delaminating to me. But without seeing it there is no way to know for sure. Most likely cause of that is too much heat or moisture in the attic.

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If your shingle is 20yrs old it is likely near the end of its life anyway, so repairing it is probably a waste of $. I’d just wait tackle the issue when the replacing the roof.

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Also just noticed it’s vaulted ceiling in certain areas also. Those are notorious for not being properly ventilated in my area.

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Curious: why would it be fine for so long, then bubble up now, if it’s venting? Could there be something blocking the venting that’s new?

I agree with IslandRoofing in all three of his responses.
Delaminated plywood.
Probably 3 ply.
And the decking wearing out faster on the cathedral.
And not to repair it because you already need to replace it.
Dont spend money on it unless you are replacing it all.
Replace the bad wood at that time.

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How long will the roof be “sound enough” to prevent water penetration? E.g., do I need to replace immediately, or can it wait for quite awhile? Financially speaking it’d be great if we had a little time… :slight_smile:

From my limited knowledge, the rest of the roof looks pretty sound.

Thanks!

Yes, you are doing great.
It is not leaking.
But it is at the end of its life.
So now you get to research, research all about roofing and start making your decision on how much it will cost and who is the best in your area to use.
No stress, No fast decisions.
Start talking to wise old friends, neighbors, church members, co-workers.

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So, are we talking like months before it’s a necessity to replace, or up to a year, or…?

Thanks!

There is no way to know without seeing it. But i’d Doubt it requires immediate action if it just decided to show up and doesn’t look that bad (even to an untrained eye).

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Your time table?
It could already be way past its time to replace or you could have a couple more years.
And even if you do have a couple more years… that time goes by lightening fast.
Since you know of no leaks, you still have time to prepare with no pressure.

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If it is plywood delaminating due to ventilation issues, very likely over a vaulted area, I would address the roof immediately. I would expect to find moisture related dry rot issues and it will only progress and cause more damage.

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plywood is several thin layers of wood glued together. The heat and condensation from improper venting has finally caused the glue to fail.

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It might be a good time to get estimates and interact with some roofers. Don’t mention your concerns and see if anyone picks up on it. You’ll get to see who writes job specs and who writes ambiguous bids, and get an idea on cost. If you get a couple that say “it’s gotta be done now” and push, they probably have no work, or are just contracting and dumping the job on the low bid subs. I’d advise finding a roofer that owns the company AND works with it.

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Dark,
I agree about staying away from roofers that get pushy. However, if I saw that issue and assumed the wood was delaminating and rotting I would tell the homeowner they should roof it sooner than later. I would then send them my bid by email and leave them alone to decide.

That’s why I said not to mention it. If I was given a drive by bid on my roof, it would be thrown in the recycle bin.

probably was bubbled a long time and not noticed,plywood probably not gapped for expansion,you can remove a couple of shingles cut the plywood and nail down or leave it alone unless you have poor quality shingles you should get 25 years out of them