Window Sill Over the Kitchen Sink — Deep, Water-Resistant Stool
The ledge behind the faucet is swollen, the paint is peeling at the corners and the caulk line has gone black. We pull it and put in a sill that can get wet.
The window sill over the kitchen sink gets splashed every day, and a wood or MDF stool there swells, peels and rots. JMB Builders replaces kitchen sink window sills across the Twin Cities metro with a deep stool in PVC, a solid-surface remnant or tile on a backer, cut to the opening and sealed to the window. Priced per window, quoted from your photos within one business day.
- Priced per window, old sill out and new one sealed in
- PVC, solid-surface or tiled stool
- Quote from photos in 1 business day
- Licensed MN contractor BC809005
The window over the sink is the wettest window in the house. Dish water splashes the stool, the sprayer overshoots, a wet sponge sits on it, and in winter the glass sweats and runs down onto it. A paint-grade pine or MDF stool there lasts a few years before the ends swell, the paint lifts and the caulk joint at the window turns black. Repainting it does not fix it.
Kitchen sink windows are also often deep. A window set in a 2x6 wall or bumped out over the counter leaves a stool that runs back a hand's width or more, which is useful for a soap dispenser and plants, and which holds even more water. The fix is a stool made of something that does not care about water, cut deep enough for the opening and sealed at the window and the wall.
JMB Builders replaces kitchen window sills across the Twin Cities metro. Three materials work: cellular PVC, which looks like painted wood; a solid-surface or quartz remnant from a countertop shop, which matches the counter; or tile set on a sloped or flat backer, which lets the backsplash run up onto the sill. We pull the old stool, check the rough sill under it, and set the new one level and sealed. Any casing or apron that comes off goes back or gets replaced. Painting is quoted as a separate line, or paint it yourself.
What you supply
- A straight-on photo of the window from the sink and one from the side showing the depth of the ledge
- A close-up of the damage: the swollen end, the black caulk, any soft spot
- Which sill you want: PVC, a solid-surface remnant to match the counter, or tile you have picked
- Tile and the trim piece for the front edge if you are going with a tiled sill
- Your paint color if the PVC stool is being painted; painting is quoted as a separate line, or paint it yourself
What JMB supplies
- Removal of the old stool and apron, and repair of the rough sill under it if it is soft
- A cellular PVC stool cut from thick stock with horns notched to the casing, glued and sealed
- Template and installation of a solid-surface or quartz remnant sill, fabricated by a countertop shop
- Cement backer, thinset, tile and grout for a tiled sill, with a bullnose or metal edge at the front
- New apron and any casing that has to come off, in a matching profile
- Kitchen-and-bath silicone at the window frame and a paintable sealant at the wall
- Photos of the finished sill in your job folder
- Painting when you want it done, quoted as its own line
How it is priced: per window
Quoted in writing from your photos within one business day. What moves the number:
- Material — PVC is the fastest, a solid-surface remnant adds a shop fabrication step, tile adds a second visit for grout
- Depth of the opening; a deep stool takes wider stock or a two-piece build
- Rot in the rough sill or the bottom of the jambs under the old stool
- Whether the casing and apron are reused or replaced to match
- Tying a tiled sill into an existing backsplash vs. a new one
- Faucet and backsplash in the way, which slows the fitting
- A second kitchen or bathroom window done in the same visit
If you want a quartz or solid-surface sill, a photo of the counter or a leftover piece from the countertop job lets us tell you whether a remnant will match.
How long it takes
A PVC stool: two to three hours, one visit. A solid-surface sill: one visit to template, a second to set the piece once the shop has cut it. A tiled sill: set one day, grout the next.
How your project works
- 1
Send photos, get a written quote
Send three photos of the space and a sentence about what you want. You get a clear, itemized quote within one business day. We only come out to measure first when the job needs a tape measure — no pressure, no games.
- 2
Pick materials, or bring your own
We help you choose profiles and materials that fit the house and the budget, or match your existing millwork exactly — or you buy the door or trim yourself and we install it. Everything is confirmed before the crew is scheduled.
- 3
Clean, precise installation
The crew shows up on time, protects floors and furniture, and installs with tight joints and consistent reveals. Photos of the finished work go in your job folder.
- 4
Walkthrough and invoice
We walk the finished work with you. If anything is not right, we fix it before we call the job done. Then one invoice, paid by check or direct deposit — no card fees, no payment links.
Situations and options
Cellular PVC stool
Looks like a painted wood stool and never swells. Cut from thick PVC trim stock, horns notched around the casing, joints glued with PVC cement, edges eased, sealed to the window with silicone. Paint it or leave it white.
Solid-surface or quartz remnant
A countertop shop cuts a sill from a remnant, ideally the same slab as your counter. We template it, pull the old stool, and set the piece on a bed of adhesive with the front edge polished. Wipes clean and matches the counter.
Tiled sill with a tile return
Cement backer on the rough sill, tile set flat or with a slight slope toward the room, and a bullnose or metal edge at the front. The backsplash tile can run up the wall and onto the sill so it reads as one surface.
Hardwood sealed on all sides
If the rest of the kitchen has stained trim, a white oak or maple stool finished on every face before it goes in holds up better than pine. It still needs the caulk joint kept up. We say so plainly, then build it if that is what matches.
Window Sill Over the Kitchen Sink — Deep, Water-Resistant Stool: questions, answered
What is the best material for a window sill over a kitchen sink?
Anything that does not absorb water. Cellular PVC is the practical choice: it looks like painted wood, cuts and nails like wood, and never swells. A quartz or solid-surface remnant matches the countertop and wipes clean. Tile works when the backsplash runs up the wall and you want the sill to match. Paint-grade pine and MDF are the ones to avoid; they are what is usually failing.
Can you tile the window sill in a kitchen?
Yes. The old stool comes out, cement backer goes on the rough sill, and the tile is set with a finished front edge, either a bullnose piece or a metal profile. Most people run the backsplash tile up and onto the sill so the two read as one surface. Plan the layout so full tiles land at the front edge and cuts hide against the window frame.
My kitchen window sill is swollen and the paint is peeling. Can it be repaired?
Not for long. Once MDF or finger-jointed pine has swelled it does not shrink back, and filler over a swollen stool cracks within a season. Replacing the stool with PVC or a solid-surface piece costs a little more than a repair and ends the problem. While it is out we check the rough sill and the bottom of the jambs, which are sometimes soft too.
How deep can a kitchen window sill be?
As deep as the wall plus whatever overhang you want. In a 2x6 wall the stool runs back several inches to the window frame before it even reaches the room. A bumped-out kitchen window can be deeper still. PVC and solid-surface both come wide enough for a deep sill in one piece; past that we build it in two pieces with a hidden joint.
Will a new sill match the oak or painted trim on the rest of the window?
Yes. On painted trim a PVC stool disappears once it is painted, and a new apron in the same profile goes under it. On stained trim, a hardwood stool in the same species, sealed on all faces before it goes in, matches the casing, or a quartz remnant sits under the stained casing and reads as part of the counter. Send a photo of the trim and we tell you which reads best.
Do I need to replace the window, or just the sill?
Usually just the sill. The stool is separate from the window; it sits on the rough sill in front of the frame. If the window frame itself is soft at the bottom corners, or the sash is rotting where it meets the sill, that is a window problem and we tell you so from the photos rather than setting a new stool in front of it.
Get a written quote for this job
Three photos and a sentence is enough. You hear back within one business day. Or text the photos to 763-204-2099.
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Read morePage reviewed September 24, 2026 · JMB Builders LLC, MN license BC809005 · All window trim pages
Where we work
Window trim near you
Based in Zimmerman, scheduling across the Twin Cities metro. Closest first: