This render repair job in St Austell showed why it pays to deal with tired or rotten work sooner rather than later. The section of boarding beneath a kitchen window had perished, leaving the wall exposed and vulnerable to damp and weather ingress.

Stripping back and insulating

The first step was to carefully remove the rotten boarding and clean the area back to a sound, stable surface. With that done, we fitted 50mm insulation behind the repair, improving the thermal performance of the wall and helping to keep the room warmer and more energy-efficient.

Tying into the existing wall

Because the surrounding wall was built in cavity block, we added stainless steel ties into each end of the repair. This bonds the new work securely into the existing structure either side, giving a strong, stable finish that won’t pull away or crack over time. We then blocked up the opening to match the surrounding wall exactly.

Render repair: scratch coat and breathable lime finish

With the blockwork in place, we built up the render system properly — starting with a scratch coat to provide a strong mechanical key, followed by a top coat incorporating lime. Lime allows the wall to breathe, reducing the risk of trapped moisture and cracking, which makes it an excellent choice for repairs like this. The whole area was finished with a sponge float for a clean, even, textured finish that blends seamlessly into the rest of the wall.

Weather-tight and built to last

The result is a repair that’s solid, properly insulated, and weather-tight — restoring both the look and the performance of the wall. If you’ve got rotten boarding, cracked render, or weatherproofing concerns around your property, we’d be glad to help.

Build Maintain — building and handyman services across St Austell and Cornwall.
Get in touch via buildmaintain.co.uk for a quote.