Related Discussions
How to remove popcorn ceiling with asbestos?

I want to remove my popcorn ceiling, but it has asbestos in it. How do I go about this safely?
How to remove popcorn ceiling with vacuum?

Is there a way to use a vacuum to remove a popcorn ceiling?
How to fix a crack in a door frame?

How to fix a door frame with a split in it?
How to fix squeaky floors under tile?

How to fix squeaky floors under tiles. Don't wish to remove the tile floor first.
What can I put on my window ledge to keep the wood from getting marked

My cats sit on the window ledge to look out the window and their claws leave marks in the wood...I have a new window and want to keep it nice... what could I put ther... See more
How do I prevent water damage to my window frame in the shower?

My window sits in my outside wall of my bath/shower. Humidity seeps into the corners despite caulking and new (bathroom) paint. Is there a product I can use to water ... See more
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 warp... See more
https://www.biggerpockets.com/forums/84/topics/328658-waterproofing-a-wood-window-frame-in-a-shower
https://arstechnica.com/civis/viewtopic.php?f=23&t=1158744
https://m.youtube.com/watch?v=CEGoTCcqUxA
Samantha can you replace it?
The rotted wood can cause mold
and also make sure there is no
water damage in the wall.
You'll need to replace it with a ledge that can handle moisture. There are plastic or composite materials you can use instead.
How badly rotted?
Have a piece of marble cut for it. Looks great and won’t rot
Once you've repaired it, put a shower rod up on the back wall of the shower and hang a clear plastic shower curtain over the window & wall. No more worry about more rot and the light still comes thru. I had this same problem. You can hang the rod higher if you like. I liked the fact that I didn't have to clean the wall, just replace the shower curtain with one from a dollar store.