Location
The Cotswolds
Stone
New dressed limestone, cut to the original profile
Scope
Eroded cill and mullion cut out and replaced

The problem

A cill takes the water that runs off the whole window, so it is usually the first part of a stone surround to go. This one had weathered back badly, with the mullion above it breaking up and the bed joints opening.

Eroded stone window cill and mullion, weathered back with open joints
Before: cill and mullion eroded and breaking up.

What we did

The failed stone was cut out and new dressed stone pieced in, worked to the same profile as the original so the repair looks like part of the window rather than a patch on it.

Repaired window with a new stone cill and mullion in fresh honey-coloured limestone
After: new cill and mullion, crisp-edged and ready to weather in.

The result

The opening sheds water properly again. The new stone stands out for now, as new Cotswold stone always does — it tones down within a few seasons.