Repair Window Sill Concrete

Drill pilot holes every 16 inches or so through the new sill s front and back edges.

Repair window sill concrete.

Trim the back edge of the new sill as needed so that its lower edge fits tightly against the siding and its back edge fits against the old wood. Repair any rotten spots on the old sill with epoxy. A window sill is the bottom portion of the window and usually but not always has a lip that overhangs the trim molding and over time these can get damaged or even rot. If the sill is painted repaint the whole sill as this will give an overall better finish.

Fix any small or medium cracks in your concrete window sill with caulk. Use the crow bar or chisel to slowly pry the windowsill off the window. Using a small putty knife starting at the window smooth the caulking flush to the sill. Run a bead of waterproof marine grade adhesive along the old sill.

Repairing window sills isn t a hard diy and i try to share simple ways to make diy improvements to your home. Finishing the mortar joint. Keep the sill in one piece so you can use it as a model when cutting the new sill. However you should be able to purchase grey exterior filler which will be a close match to the concrete.

Remove the excess material build up on the putty knife. Fit the narrow tip of a bottle of silicone latex caulk into each crack and overfill it by about inch. Resist the urge to keep touching and fiddling with the look of the smoothed caulking you will probably make it look worse. Use a utility knife and if necessary a hammer to carefully break and remove any caulking or sealant that s binding the old sill to the window frame.

Repairing a concrete window sill could appear to be a major job that s far beyond the skills of the average diyer but with the proper knowledge tools material and preparation you might find it s worth considering having a go yourself unless a complete rebuild is necessary. Gray would look modern. You may also need to pry away trim material known as side casing. Scrape away any mess with the edge of the knife.

Your sill probably isn t this fancy. Fill the crack with multi purpose exterior filler.