How To Replace Rotted Window Sill

Q: One of our windowsills appears to be rotting. Can it be replaced without ownership a new window?

—Beak Bailey, Baldwin, Mo.

David Raymond, Raymond Blueprint Builders, replies: Sticking out into the weather condition year afterwards year, forest windowsills take quite a beating. They tin final for decades if you just keep them make clean and protect them with a coat of paint. But when water gets trapped in or against them, as happens with improperly flashed windows, rot can take hold.

A simple epoxy repair volition exercise the trick if the rot is confined to a small area, but if more than 10 percent of the sill is rotten, the old sill should be cut off and replaced. For this project, I used a solid piece of Kleer cellular PVC sill that matches the contour and thickness of the other sills on the house. It costs less than a piece of clear, milled red cedar and is paintable, but no affair how many times it gets wet, it can't rot.

Step-past-pace tutorial renders beneath OTHER VIDEOS thespian. Keep scrolling!

Step 1

Remove the Side Casings

Photograph by Ryan Benyi

The casing comes off to articulate the way for removing the old sill. If the casings are rotting, as hither, replace them, too. Piece through the caulk bead between the siding and the casing, then carefully pry off each piece. Save the trim to use every bit templates for the new ones. Make certain the flashing behind the casing is intact and properly installed behind the siding.

Stride 2

Saw Off the Old Sill

Photo past Ryan Benyi

Make a plumb cut flush with the sheathing forth the length of the rotten sill. A circular saw with a beveled blade can handle virtually of the cutting, just for the sill ends where a circ saw can't reach, switch to a multitool, similar this Fein Multimaster equipped with an aquiver saw blade. Smooth the cutting with a few strokes of a hand plane.

Step 3

Apply the Agglutinative

Photo by Ryan Benyi

Repair any rotten spots on the old sill with epoxy. Trim the back border of the new sill as needed so that its lower edge fits tightly confronting the siding and its back border fits against the old wood. Drill pilot holes every 16 inches or so through the new sill's forepart and back edges. Run a bead of waterproof, marine-form adhesive forth the old sill.

Step 4

Attach the New Sill

Photo past Ryan Benyi

Printing the new sill into the adhesive, and immediately clamp it in place by driving 3½-inch deck screws through the plastic and into the woods. Cease when the heads are about ¼ inch beneath the sill surface. Immediately wipe up any adhesive that squeezes out. Fill any gaps between the erstwhile and new sill with adhesive.

Step 5

Hide the Screwheads

Photograph by Ryan Benyi

Cover each screwhead with a dollop of a white, 2-part acrylic adhesive, such every bit Bond&Fill FastCure. (This also works as an adhesive in Step 3.) Overfill the recess slightly. When the adhesive hardens completely, in near xxx minutes, sand it flush.

Step 6

Install the Side Casing

Photo by Ryan Benyi

Squeeze a dewdrop of caulk beside the ends of the siding, and nail the new casing in place. Here, I used cellular PVC trim boards and 8d stainless-steel ring-shank nails. Set the nailheads slightly below the surface, and cover each i with a dab of the two-part adhesive. Later the dabs harden, sand them flush.

Source: https://www.thisoldhouse.com/windows/21016539/how-to-repair-a-rotted-windowsill

Posted by: gonzalesandlever.blogspot.com

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