What's the most inexpensive way to seal skylights?

Jan Troxel
by Jan Troxel
we have used two or three sealants on our two ceiling skylights, but nothing has worked! Now our ceilings are ruined!

  7 answers
  • Mabel Caron-Regimbal Mabel Caron-Regimbal on Jul 26, 2017

    We had our roof refinished by professionals and it still leaked so we had it removed.

  • Susan E Susan E on Jul 27, 2017

    I just had my skylight replaced. It was installed in 1970's and was made out of an old plastic compound, and it had begun to crack and leak. Cost me just over $1500. But the newer material has better insulation properties and will probably make a difference in my winter electricity (heating) bill. We are in mountains in California, just above the snowline, so we get weather. You might want to rethink resealing and think replacement.

  • Carol Carol on Jul 27, 2017

    It could be that when it rains, the water flowing down the roof builds up on the upper edge wall of the skylight and then reaches the underedge of the skylight 'lid'. Then it begins to seep/leak/flow inside. I had this problem and solved it by building a small dam a few inches higher on the roof than the skylight. I used metal flashing, about six inches high. Slip the bottom edge under the edge of the roof shingles, then bend it up. This will deflect the flow of water to the sides so that the skylight wall is more protected. Hard to explain without pictures. Perhaps you should call a skylight professional. Skylights make such a difference to a room that I would be hesitant to remove a skylight altogether. In a pinch, as a temporary fix, you could just lay a 2x4 up there, or even some bricks or blocks. The goal is to not have so much water hitting the upper riser edge of skylight.

  • T davidson T davidson on Jul 27, 2017

    i have that problem too. I hate skylights. Mine is in the bathroom and I've got to replace a whole section of my ceiling but got to find the leak first

  • Edbluga Edbluga on Jul 28, 2017

    You don't mention the roof material, or if the sealants you applied were from the inside or on the roof deck. When I replaced the asphalt shingles on my parents house I took that opportunity to replace the plastic bubble skylight with a real, opening skylight(Velux). I installed an ice/rain barrier membrane around the opening and used the (required by them) vendors metal step flashing as I replaced the shingles. If you have the ability to remove the shingles from around the skylights, add a rubber membrane, reshingle that area with step flashing, you should end up with a nice, dry ceiling. And alternative to step flashing would be to have a one piece metal flashing made, but the individual L shaped step flashing was a relatively easy install since I was doing a reshingle anyway.


    water damage from roof leaks are so discouraging since a little water goes long way in damage.


    A Velux installation video https://vimeo.com/92860434


    good luck

  • Jan Troxel Jan Troxel on Jul 29, 2017

    Thank you! That will be our next step! ☺😊


  • Terry L. Black Sr. Terry L. Black Sr. on Jul 29, 2017

    Edbluga explained it perfectly and is absolutely correct. If anything comes up through your roof IE: vent pipe, dormer, chimney, etc... it MUST have the proper build-up of shingles and flashing.