Sand the sill with 100 grit paper to smooth the surface for priming.
How to fix cracked window sill.
Sand the surface with a 100 grit sanding sponge.
Then we used a hammer and banged popped the sill upwards being careful to avoid any further damage.
Do this before trying to fill the crack with any kind of filler.
We pulled out the rest of the nails that were left behind.
You will need to raise one side or the other with plastic.
How to repair a concrete window sill preparation.
Scrape the sill with a metal scraper to remove chipped or peeling paint.
Sometimes a skirting trim or board is installed under a sill like this to help support the sill.
Resist the urge to keep touching and fiddling with the look of the smoothed caulking you will probably make it look worse.
Any wood that is loose or rattling.
Finishing the mortar joint.
Step 2 remove loose wood.
Remove any existing paint and dirt first from the area by scraping and wiping the area down with a rag moistened with tsp.
How to repair weathered wood sills.
Remove the excess material build up on the putty knife.
Switch to a 220 grit sanding sponge to finish off with a very smooth surface.
It is important to prevent water moisture from getting under your window this is a short video to show how easy it is to seal up the cracks in your concret.
Using a small putty knife starting at the window smooth the caulking flush to the sill.
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.
Rub the surface of any and all damaged areas with a stiff brush.
With any luck this re work may keep the crack closed up.
Use a random orbit sander for the best results.
Dig out damaged wood image copyright.
Step 1 use a putty knife or a paint scraper to remove the peeling and cracked paint.
Remove as much concrete debris as possible.
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.
Fit the narrow tip.