Replies

1. 
   freyr_design | Nov 17, 2024 10:05am | #1

   That is shingle buckling and generally caused by movement in your roof deck, sometimes by wrinkling of underlayment. If you have/had humidity or moisture content issues with the roof deck at install or if venting is not adequate it will cause the roof deck to shift. It should be addressed sooner than later.

2. Expert Member
   DCcontrarian | Nov 17, 2024 11:17am | #2

   I would guess the underlayment is puckering. I've seen it do that and then settle down over time. Do you know what's between the shingles and the sheathing?

1. 
   nynick | Nov 17, 2024 12:23pm | #3

   Yes. Ice and Water shield. Let me see if I have some pix of that.

1. 
   Malcolm_Taylor | Nov 17, 2024 12:37pm | #4

   nynick,

   The vertical bulges which appear to be about the same length as a roll of underlayment support DC's suggestion that's what is to blame, not the shingles themselves.

1. 
   nynick | Nov 17, 2024 02:19pm | #5

   Thanks Malcolm. I agree on roof #1 that that is probably the case, but it looks like crap. Should I make them tear it off and redo the roof?

   On roof #2 it appears too randomly to be ice and water shield, unless it was put down improperly.

1. 
   Malcolm_Taylor | Nov 17, 2024 02:38pm | #6

   nynick,

   It's always hard to diagnose problems from photos, but if you are having an unusual issue with one new roof, the chances are the problem with the other has a similar cause. What does your roofer say?

3. 
   user-723121 | Nov 17, 2024 03:36pm | #7

   OSB will swell at the seams and show up on many roofs, especially with the old 3-tab shingles that laid really flat.

4. 
   andy_ | Nov 20, 2024 12:26am | #8

   Roof #2 has ridges popping up at about the same spacing as 4x8' roof sheathing so I'd suspect some OSB edge swelling or cupping of sheathing that doesn't have H clips to keep the edges in plane.

5. 
   nynick | Nov 20, 2024 08:10am | #9

   Thanks to everyone for the replies.
   The roofers came and ripped up some spots. Roof #2 had air pockets under the ice and water. Roof #1 had the gable extended on the old roof and the carpenters used 3/4" plywood next to old 1" roof sheathing. They applied 1/4" luan and re-roofed. Hopefully that solves the problem.