Use a paintbrush to apply concrete bonding agent to the entire window sill.
Repair cracked concrete window sill.
Apply a 3 8 inch thick layer of concrete all over the sill with a trowel following any contours to mimic its original shape.
To avoid this check regularly for.
How to repair sandstone window sills.
Repairing a woden sill.
As this may.
Resurface stained or cracked concrete window sills with new concrete.
Window sills are designed to divert water away from the house and as a result they get a battering from the weather over time wooden sills can rot and concrete window sills can develop cracks.
Worn or loose joints.
If sills are sandstone the stone tends to deteriorate with age exposure to rain snow and freeze.
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.
Cracked or worn paintwork.
Rub off flaking paint or loose concrete along the crack with the wire brush and make sure to clean out any moss that may be growing inside.