Removing old render has pulled out some chunks of brick

[ToolbeltDandy]

I was removing blown render from the garden wall and removed some pieces of brick along with it. Should these holes be repaired with mortar or anything, or should I just stuff the holes with render? The old render is practically like soil. There were plants' roots and insects crawling around in there!!

 

[ToolbeltDandy]

Apparently, I can just fill the holes with the scratch coat, so it doesn't really matter.

 

[roughcaster]

If i were you, i'd fill out the "deep areas" individualy,, scratching each single area as you go. When you have all the deep areas filled, and the overall surface is fairly even, then scratch coat as per normal, over the whole wall surface. If you try to fill out the deeper areas in one go, it will slump, causing cracking of the mortar. Add waterproofer into the render mix, even for the filling out of the deeper areas. Give that old brickwork a really good soak down as you go too, and keep the direct sun from drying it out too quick. If you can, cover the job with a really damp sheet/polythene. The slower render dries out, the better,, also give the deeper bits a day at least between coats, plus, give the scratched wall surface a wet down before you render top coat.

 

[ToolbeltDandy]

Okay, thanks; I'll do just that. Should I use the same 4:1:1 and 5:1:1 (sharp sand to cement to hydrated lime powder) for the scratch coat and top coat as usual? The bricks have the texture of sandstone?

Incidentally, the sand contains lots of small stones, and when I'm smoothing out an area, the float catches on the stones and pulls them, causing small holes to appear in the render - is that normal? Are there alternative options apart from sharp sand?

 

[stevethespreader]

Are there alternative options apart from sharp sand?

use plastering sand which is graded sharp sand without the stones

 

[ToolbeltDandy]

Thank you. Can I use a rotostop SDS drill to chisel away the old render or is that likely to damage the wall?