Hi, I need to do some patching up on in interior of an external wall where existing sand/cement has broken off.
There's a section about 8 inches high running the length of two walls, one wall being the window wall. There was coving here until it was ripped down as a new board was put up on the ceiling. Off with it crumbled off varying depths of what I've been told is sand/cement (original from when house was built in 60s) and is back to bare block. I've thought about just boarding it but in some places the boards will stick out past the existing wall and would be too much even for a skim to overcome. 8ts because walls are out in places so want to go down the sand/cement patching up route.
My question is, do I need to add in some liquid waterproofer (e.g. sika which we already have from another job) into the sand/cement mix for the window wall or is waterproofer only needed when rendering outside of a property? Thanks.
There's a section about 8 inches high running the length of two walls, one wall being the window wall. There was coving here until it was ripped down as a new board was put up on the ceiling. Off with it crumbled off varying depths of what I've been told is sand/cement (original from when house was built in 60s) and is back to bare block. I've thought about just boarding it but in some places the boards will stick out past the existing wall and would be too much even for a skim to overcome. 8ts because walls are out in places so want to go down the sand/cement patching up route.
My question is, do I need to add in some liquid waterproofer (e.g. sika which we already have from another job) into the sand/cement mix for the window wall or is waterproofer only needed when rendering outside of a property? Thanks.
