Crack repair and crack stitching
A crack in render is a symptom, not the fault. Some are shrinkage cracks in the render itself; others follow movement in the masonry behind, a lintel, a control joint that was never formed, or two materials expanding at different rates.
Filling a crack without understanding which of those it is simply moves the problem a few millimetres to one side. We work out what is moving first, then choose a repair that can live with that movement.
What we look for
Stepped or diagonal cracking
Cracks that follow mortar joints or run diagonally from window and door corners usually relate to movement in the structure behind the render.
Straight horizontal or vertical lines
Often associated with lintels, junctions between different materials, or joints that were never formed when the wall was built.
Fine map cracking across the face
A network of hairline cracks generally sits in the render or coating itself rather than the structure, but still lets moisture in.
Cracks that keep coming back
A repair that reopens in the same place is telling you the movement was never accommodated.
How the work is carried out
- 01
Diagnose the movement
We trace each crack, look at where it starts and stops, and judge whether it is live, historic or confined to the render.
- 02
Reinforce where required
Where the substrate needs tying back across a crack, crack stitching is used to reinforce the masonry before any render work begins.
- 03
Cut out and repair
The crack is opened up, dust and loose material removed, and the render rebuilt with the appropriate material for the depth and width involved.
- 04
Re-texture and coat
The repaired area is re-textured as part of the wider elevation and finished with the Dulux Acratex system so the repair does not telegraph through.
Structural movement occasionally needs an engineer's input. If we think that is the case, we will say so rather than cover it up.
Get this looked at
Send a few photos and a short description of the property and Mark will come back to you, usually within two business days. A site inspection is normally needed before a written quotation.