Fix Cracked Window Sill

You will need to raise one side or the other with plastic.

Fix cracked window sill.

Switch to a 220 grit sanding sponge to finish off with a very smooth surface. See below for tools and a shoppin. Check for sill movement such as a crack where one side has settled or is down farther than the other side causing a crown and a crack. Once it is ready you can apply it to the surfaces that require stabilization and repair.

The sill or lower horizontal wood plate extends into the room creating a target for impacts and other damaging factors. Do this before trying to fill the crack with any kind of filler. Then we used a hammer and banged popped the sill upwards being careful to avoid any further damage. Repairing weathered sill finishes is simply a matter of sanding and repainting.

Step 1 fix any small or medium cracks in your concrete window sill with caulk. We pulled out the rest of the nails that were left behind. Fit the narrow tip of a bottle of silicone latex caulk into each crack and overfill it by about inch. It is possible to fill in quite sizeable holes with the masonry filler method but if the edges are crumbling away you ll need to build moulds to shape the sill correctly a job that s probably beyond most diyers skill level.

Spread and flatten the caulk with a small putty knife. First we ran a cutting blade this is my favorite caulk removing tool around all the edges including between the underneath trim and the window sill. Repairing window sill damage is typically simple. Caulk tube versions are easiest to use just squeeze the sealer into the crack then smooth it with a plastic spatula or putty knife and peel off the tape.

This old house general contractor tom silva shares some tricks of the trade for installing a new long lasting windowsill. A split cracked or simply weathered window sill can detract from an otherwise beautiful window. If there is not one there you may want to push up the cracked sill and install a skirting board to help support the sill. Sometimes a skirting trim or board is installed under a sill like this to help support the sill.

Step 1 use a putty knife or a paint scraper to remove the peeling and cracked paint. Chip says apply painter s tape around the edges of each crack. Sand the surface with a 100 grit sanding sponge. Fill thin fissures 1 8 inch to 1 4 inch wide with a concrete patch sealer.

Other sill repairs can extend from basic maintenance to reconstruction of the sill. Scrape away any mess with the edge of the knife.