GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

Fixing Skylight Installation Problem

JTaylor | Posted in General Questions on
I had my shingle roof replaced last week by my roofing contractor and we also replaced aging skylights with new curb-mounted skylights (all done by the same contractor) .  The contractor is a well-regarded roofer so I believe the flashing and shingle work around the skylight was properly done.
The problem is that due to issues with the skylight sizing, the contractor couldn’t use 2×4 lumber for the curb and built the curb out of thinner lumber (1 1/8 inch) to better fit the existing opening in the roof.
On one of the curbs, I can see that the wood has split at one of the nails securing the curb to the roof.  The curb is already fully flashed and shingles are installed.  So if I ask the roofer to re-do the curb, they will have to pull off the flashing, shingles, etc.
– Climate zone 4A
– Roof pitch relatively steep, ~60 degrees
– Skylight is located in a large, well-ventilated living area
1. Should I have my contractor re-do the skylight installation to rebuild a new curb or leave it as-is to not pull off the brand new roof work?  Is trying to reinforce the wood with screws an option?
2. Should I weatherstrip the crack between the curb and interior drywall?  The indoor plan is to cover up the curb and crack with a PVC trim board.

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.


  1. Expert Member


    I'd leave the crack alone. I don't see how it affects much.

    What you might want to consider is adding a layer of foam to the interior of the curb to limit heat loss.

    1. JTaylor | | #3

      Thanks Malcolm, appreciate the advice!

  2. Expert Member
    BILL WICHERS | | #2

    If the curb is still physically secure, the crack is probably not an issue. It might be worth injecting the crack with some liquid nails or polyurethane construction adhesive, a sealant, or some wood putty. The construction adhesive would be more structural(ish), wood putty would be better if you want to finish the wood with paint. Any of those will seal the crack against being a potential air leak.


    1. JTaylor | | #4

      Helpful, thank you Bill, I will look at injecting some construction adhesive to close off the crack.

  3. steve41 | | #5

    It may be overkill in this case, but I have used this product for structural repair:

    Great product for interior/exterior wood repairs.

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |