How do I repair the interior top panel of my bay window?


Hello DIYers, I’ve moved into a house with a bay window that needs patched up before painting, but I can’t figure out a good way to do it. It appears to have warped from previous water damage, but being a new to me house, I can only guess. Thanks for any ideas!

q how do i repair the interior top panel of my bay window
q how do i repair the interior top panel of my bay window
q how do i repair the interior top panel of my bay window
  15 answers
  • on Aug 23, 2020

    I think you should take that warped piece down and replace it. It’s a bit of a job - but it will allow you to see what’s going on underneath and make sure the cause of the water damage problem is fixed. You 100% want to make sure it’s fixed. Water is your enemy!

  • Cheryl A Cheryl A on Aug 23, 2020

    Hi Brek

    You need to find out why it has warped and be sure there is no water damage or water coming in that area before doing any painting. Is this a sheet of wood that has warped? Take down the piece that is warped and see what is going on under it, then do any repairs (could be from a roof leak) and replace the wood and paint. It appears to have two dark or black spots that would indicate mold which you want taken care of so it doesn't spread..

  • K. Rupp K. Rupp on Aug 23, 2020

    Hi Brek,

    The first thing you have to do is check on the outside and make sure the flashing and caulk above the window is in tact. If not, this will just keep happening so that would need get fixed first before anything. That definitely looks like water damage. Guessing that the veneer has separated from the plywood there. What you can try is to get glue in all of the peeling sections and then take an inch by inch strip of wood and temporarily nail it into the plywood which would act as a clamping mechanism to bring the peeling sections up tight against the plywood underneath. After removing the wood strip, just fill the nail holes and paint. Use long nails to make it easy to remove the nails after the glue has dried; and don't drive the nails all the way into the wood strip. The glue should be a good wood glue like TIGHTBOND(also water resistant). Good luck!

  • looks like you will have to replace that whole top panel. Something in the window must not be sealed correctly since there is a leak.

  • Dee Dee on Aug 23, 2020

    You definitely need to find out why this has warped and if there is any water damage underneath. You certainly do not want mold. Then the piece needs to be taken out. You will need to cut a new piece and replace. This way you will have no worries. But first find out what is going on underneath.

  • Annie Annie on Aug 23, 2020

    Replace that top board after you are sure that there is no more water leaking through

  • William William on Aug 23, 2020

    You will need to find out if it still leaks first. You can use a garden hose on the outside and spray in different areas to see if the leak is still there. It will need to be corrected. The top panel is part of the bay window so removing and replacing can be laborious. What I would do is cut two 2x4's the width of the window. One for the top and one for the bottom. Place one 2x4 on the sill and have an assistant hold one along the top. Measure the height and cut a few 2x4's about 1/2" longer to use as braces. Squeeze wood glue into the open joint. Then place one 2x4 on the sill and have an assistant hold one on top. Place the brace 2x4's against the top and bottom 2x4's and pound them straight with a hammer closing the gap. If they are too short to close the gap use some pieces of wood to add length. Leave the 2x4's in place for a few days for the glue to dry.

  • Ken Erickson Ken Erickson on Aug 23, 2020

    Assuming no leaks now. It may have just been thin material that wasn't secured to the framing very well. Heating and cooling next to a window along with humidity could cause damage. You can take it down and use it for a template for a new piece. Paint it first and re-install. I would use some construction adhesive on the framing and then fasten it up. Touch up paint when done.

  • Vimarhonor Vimarhonor on Aug 23, 2020

    Hello. I would remove warped panel observe for water leaking. Repair leaky situation if necessary. Use the warped panel for cutting replacement product.

  • Brek Brek on Aug 23, 2020

    Wow! Thanks to all the replies, this is my first post and I never expected such quick and helpful answers. YAY!! The leak is no longer active, that much has been tested and confirmed. There’s always a possibility of hidden damage tho... FYI the black spots are NOT mold, just old hardware and holes from the previous owners blinds. Clamp & glue or replace, I’ll do some closer looking and decide as needed, THANKS AGAIN!!

  • Daniel Steving Daniel Steving on Aug 23, 2020

    It is peeling off because either water is leaking in the windows roof from outside OR there is no insulation in that roof. condensation probably builds up under that veneer in winter when you have have heat on and that veneer sweats. I install bay windows and most contractors don’t insulate under the “seat” outside so your exact situation happens on the veneer wood on the “seat”. Good luck!

  • Betsy Betsy on Aug 23, 2020

    Hi Brek: You can nail it back up, but first find out why it's happening and fix that. You can also get some molding to put around the top and/or sides after nailing. Can you ask the previous owners or realtor why it happened? Was there no inspection made pre-sale? This should have been addressed then by the inspector. Did you get a home warranty or is there some sort of warranty? If not, then take a peek under the wood with a flashlight and see what you can see. Good luck

  • Oliva Oliva on Aug 24, 2020

    Your home disclosure documents should have revealed any water damage. If not, you may have a legal claim for failure to disclose. Act on this ASAP, in the event the previous owner should have corrected the issue.

  • That's wonderful that there's no mold. That's the big worry. I would replace that board. What a pretty window. Enjoy the space!

  • Agnes Chrzanowska Agnes Chrzanowska on Aug 31, 2020

    it is warped piece of wood because of moisture ... I would remove it and make sure nothing is there and replace with new one

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