Hi all,
I’ve got a 1920s solid wall detached house in Derbyshire with roughcast render throughout. The south elevation has developed a problem on a projecting concrete window overhang, the render has blown off the top and front faces, exposing the substrate underneath which is damp and in places crumbly.
I’ve already identified and am fixing the likely water source, an old open hopper directly above which wasn’t sealed against the wall, allowing water to track behind the render over many years. New hopper going on this weekend, properly bedded in MS polymer sealant.
The rest of the south elevation render is solid. tapped it, no hollow sections, just some hairline and minor cracks which I’ll fill with flexible exterior sealant.
The house needs external wall insulation and cladding within the next five years. Full rerender now would be money wasted, I just need the exposed substrate protected and watertight until the bigger job happens.
What I’m thinking:
Once the substrate has dried out properly, I’m considering:
• Chipping back to brick if the remaining render is too crumbly to treat
• If solid enough, stabilising solution followed by breathable masonry paint
• Or Stormdry directly to bare substrate then breathable masonry paint within the 3-10 day window
Questions
1. Is going back to bare brick on the overhang the right call if the remaining render is friable?
2. Any compatibility issues with Stormdry over a stabilising solution?
3. Any product recommendations for a breathable off-white masonry paint that’ll sit reasonably well against aged pebbledash?
Photos attached. Grateful for any advice, thank Iyou.
I’ve got a 1920s solid wall detached house in Derbyshire with roughcast render throughout. The south elevation has developed a problem on a projecting concrete window overhang, the render has blown off the top and front faces, exposing the substrate underneath which is damp and in places crumbly.
I’ve already identified and am fixing the likely water source, an old open hopper directly above which wasn’t sealed against the wall, allowing water to track behind the render over many years. New hopper going on this weekend, properly bedded in MS polymer sealant.
The rest of the south elevation render is solid. tapped it, no hollow sections, just some hairline and minor cracks which I’ll fill with flexible exterior sealant.
The house needs external wall insulation and cladding within the next five years. Full rerender now would be money wasted, I just need the exposed substrate protected and watertight until the bigger job happens.
What I’m thinking:
Once the substrate has dried out properly, I’m considering:
• Chipping back to brick if the remaining render is too crumbly to treat
• If solid enough, stabilising solution followed by breathable masonry paint
• Or Stormdry directly to bare substrate then breathable masonry paint within the 3-10 day window
Questions
1. Is going back to bare brick on the overhang the right call if the remaining render is friable?
2. Any compatibility issues with Stormdry over a stabilising solution?
3. Any product recommendations for a breathable off-white masonry paint that’ll sit reasonably well against aged pebbledash?
Photos attached. Grateful for any advice, thank Iyou.
