Not sure why my photos are uploading so stretched and skewed

I'm hoping to do the exact same thing. My trim is water damaged a lot like yours.

I don't see why not. My granite countertop installer suggested I do the window sill in granite, so I'm guessing it's quite doable. I don't have any pictures as I ended up doing the window sill that came with the window. Gorgeous backsplash, btw!

Slide a piece of 1/2" solid surface sill under that window crank with a front edge build up and return ends for the side casings to die into. And no nasty casing rot, no matter how much you splash.

Sure you can. Any good trim carpenter can do it. They know how windows are framed.

Of course. When I had my bathroom remodeled, I had a shower installed where a window was. The complete inside window frame + sill was replaced with waterproof materials. We used Onyx.

Onyx windowsill website

As with the boy scouts: be prepared. Start pulling the trim off and you'll get to see the edges of the drywall underneath, which may also have water damage, which you may also want to remove...and then you'll see the framing timbers, which may also have water damage, and...

But it has to be done at some stage.

Yes, I used a solid surface on my sill and stool to protect that wet area in my kitchen. It coordinated with the tile we installed for the backsplash.

I’m no help to your question....

what tile is that and where did you get it?

Yes, it's possible.

Whenever water damage is noticed it should be fixed asap to prevent other water damage unseen.

When you get that off, inspect the area behind. It may be wet. Air it out. Be prepared it may be more to fix.

Another type of waterproof barrier is needed to prevent water from damaging wall, cabinet, & floors.

Just replacing the same will bring same results later.

"Another type of waterproof barrier is needed to prevent water from damaging wall, cabinet, & floors.

Just replacing the same will bring same results later."

When I first saw the picture and the rot, I thought "Check the window flashing.", however, it's obvious the rot is caused by wet hands flinging water when the faucet is used. A solid surface sill will never rot under these conditions.

Like Joe said, check the flashing, your window could have a leak... Other than that, remove or cut back lower extension jamb back to the window and put in a new marble or granite window sill in its place and tile around. Here is an example how it's done.

Marble is a terrible choice for a kitchen window sill. You'd better never remove that potted plant once you put it there.

I don't think you can put a pot on a 2-3" ledge. In any case 95% of the time it will be granite as the countertop ... As marble goes, seen marble sills in a few homes and they didn't have any issues...

I had a similar problem...when I had the kitchen done I had a shorter window by 6 inches put in and ran the wall tile under the window it is 2 tiles high but stops the window getting wet !

My 80s house has all marble window sills and so did the 80s house I grew up in :-) never had any issues. I actually prefer marble especially over my 1st homes wood ones but probably because it reminds me of the house I grew up in :-) and you never have to paint them

I totally agree with Elizabeth B about the marble window sills. We have marble sills in our office and it's so much cleaner and looks striking.

I'll see if I can find a solid window sill...I'm guessing I'll have to get it made. I thought there might be a way to use the tile to do this.

And if I do replace the sill with stone, do you think I should remove the entire window trim? The backsplash is only going as far as the bottom of the cabinet.

ps: I'm doing the job myself. I've installed a marble backsplash before, but I kept the window frame and trim in that case.

Sarah, here is a photo with the name of the tile. It's from Floors Plus (Canada) and supplied by Olympia Stone.

I found this photo, but they have no window trim:

I used an engineered stone sill for my window in the exact same situation. It looks beautiful, very neat and tailored, and of course no rot or water damage.

Those look nice. Should I keep the wooden trim along the sides and the top?

Waterproof barrier inside resting on countertop and sealed. Backsplash.

Ways to keep trim

Example like #2 above

That looks perfect. I will keep the trim as shown in the photo