Hump in the Roof Shingles

Replaced a window sash Saturday for a guy from California that owns 5 two story apartment buildings in town.
As I was driving out in front of another building, I saw this on the roof.

I sent him some pictures and wants me to investigate and correct the problem.

I just thought to post it here and see if you guys could figure it out.

The guys at NACBI already know what it is.

Thought I would post it here for discussion.

Here is another view.


1 Like




Buckled sheathing due to missing collar ties and/or H-clips?

Little warm, but this was like 6’ from the edge of the roof. :slight_smile:

Did the shingles above slide?

Wood board decking high moisture content may shrink or low moisture content may pick up moisture and expand.

This can result in the shingles buckling horizontally.

Blocked air flow just after the vent baffle. Moisture expanded the plywood and caused delamination and separated at this area.
Basically it was cause by ice dam in the blocked area.

It’s Maine…an ice dam ripped the gutters off and buckled the shingles. Granted, I’m in TX and have never experienced an ice dam so that might be totally off base.


Possible storm/ wind damage (fascia is also damaged). Just inspected a home that had hail/ wind damage and a small section of shingles lifted and curled under. Looked almost exactly like your photo.


Nope! :slight_smile:

im sticking with martians…

Im sticking with Martians…

Someone jammed a shovel up there to clean off snow/ice?

Actually, I liked the Snake Jim. :mrgreen:

Missed vent? Could also be from a perlin under the shaething popping up due to expansion. My best guess is that it was a wood roof at one point with perlins. It was sheeted over to be shingled. Am I close?

That did cross my mind when I first saw it. :slight_smile: