Masonry repairs
Covering a crack or hollow area without removing loose material can leave the same failure beneath a new surface.
Ask about render repairs · View exterior painting
Render protects and finishes the outside wall. Local failure can result from impact, water behind the finish, movement, poor preparation, incompatible materials, corrosion at beads or repeated frost action.
Signs of local failure
- visible cracks or open edges;
- hollow-sounding areas;
- bulging or loose patches;
- staining or algae;
- rust marks around beads or fixings;
- flaking paint over the render;
- repeated repair lines;
- water entry after wind-driven rain.
Do not knock loose high-level render from below. Keep people away if material may fall.
Find the water source
Gutters, downpipes, parapets, copings, sills, roof abutments and cracked sealant can allow water behind render. Ground levels and splashback can affect the base. Those issues should be considered before the finish is restored.
Remove only what has failed
Local repair begins by defining sound edges. Loose material is removed carefully, the substrate cleaned and prepared, and compatible coats or reinforcement applied as the system requires.
A patch that is too hard or differently textured can move and weather differently from the surrounding render.
Cracks and movement
Fine stable surface cracks are different from widening cracks through the wall. Significant, recurring or structural movement needs appropriate assessment before rendering.
Matching and decoration
Texture, aggregate, thickness and weathering affect appearance. A local patch may remain visible even after coating. The repair must cure and dry before suitable exterior paint is applied.
Weather
Strong sun, rain, frost and drying wind can affect render. Protection and timing should suit the materials used.
Questions about render repair
Can cracked render simply be filled?
Only if the crack is stable and the surrounding render remains bonded. Loose or moving areas need a different repair.
Why does the render sound hollow?
It may have lost bond with the substrate. The extent needs checking because a surface coat cannot restore hidden adhesion.
Can you match pebbledash exactly?
Exact matching can be difficult because aggregate, colour and weathering vary. A sample or wider finish may be discussed.
Should the whole wall be painted after a patch?
Often a wider coating gives a more consistent appearance, but only after the repair is ready and the paint is suitable for the wall.
Show every edge of the damaged area
Include the wall above and below, nearby openings, roofline and ground level.