tanking

[Robbo030]

Hardwall is gypsum based so not right material
You either need a sand cement (2 coats no waterproofer 1st coat.) or I use limelite renovating over tanking as it doesn't slump and run down wall like sc

Thanks, would you recommend scratch coating it before hand then? I was hoping to one coat it with s&c but I'd imagine from what you're saying is it don't grip well on the tanking?

 

[martinemj]

Unless walls are really straight then a scratch over tanking best ....you can't really put it on thick enough without slumping ...so one coat is not impossible but difficult to do..

 

[Robbo030]

Unless walls are really straight then a scratch over tanking best ....you can't really put it on thick enough without slumping ...so one coat is not impossible but difficult to do..

Know what you mean about the slumping...nightmare think I'll put a scratch coat in with no waterproof agent then I'll mix a second coat up with SBR and devil float to finish, ready to plaster skim in couple days (hopefully) you wet the tanked wall before 1st coat of render with water or PVA/SBR ?

 

[martinemj]

You can sbr yes...