Cost to Replace a Rotted Window Sill

Cost to Replace a Rotted Window Sill

How much does it cost to replace a window sill? A sill is a prominent part of a window that juts out at its base so a damaged one is an eyesore. The contractor cost to replace a window sill is $233 vs. doing it yourself for $50 and saving 79 percent.

National Average Improvement and Repair Cost
Diy Logo Hours Pro 1.3 DIY 2.5
Money Pro $233 DIY $50
Per Unit Cost
Per Unit Cost $233 Total Cost

By Gene and Katie Hamilton

When an old window sill is rotted or damaged beyond repair, the best alternative is to replace it with a new one. Often the drywall at the base of the window is damaged by moisture from condensation, or a hungry dog who used the sill as a chewing toy. Whatever the cause, installing a new window sill provides protection and adds a stylish detail to the window. If there is moisture damage to the wall, make the repair and then replace the sill. And if your window was built without a sill, adding a new one will be a home improvement upgrade.

There are vinyl window sills that are installed with adhesive in two styles. One has a straight cut basic style, and the other wraps around the sides of the wall, giving it a custom look. At the manufacturer's Web site,, you can learn about the different styles that match your window frame, how to measure a window for a new sill and what's involved installing one.

A carpenter, handyman or window replacement installer will charge $233 to replace the old sill with 4-linear foot sill that matches the window trim, assuming no repair work like fixing the window frame or repairing drywall on the window or wall is required. That will cost more. You can buy the new window sill for $50 and do it yourself, assuming you have some carpentry skills and tools, and save 79 percent. You'll need a tape measure, carpenter's square, saber or small circular saw, construction adhesive and weatherproof caulking and a caulk gun.

Click here to get to Home Advisor and it will open in a new tab and you’ll have to answer some basic questions about your job followed by carpenters in your area to do the job.

That sums it up. Knowing the average cost to replace a window sill lets you compare DIY costs with what you can expect to pay a handyman or window replacement installer. For a local cost add your ZIP

Code.Improvement and Repair Cost Updated 2020

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