Q. Can any of Cromar Products be used to paint onto an internal wall ie Shower room & then Tile over – to ensure extra waterproof protection if the Grout fails? A Q. Can any of Cromar Products be used to paint onto an internal wall ie Shower room & then Tile over – to ensure extra waterproof protection if the Grout fails? A. Yes – mix 1lt SBR with 1kg of Cement, apply this to wall & once dry – tile in usual way. Cromar2020-03-17T14:20:00+00:00 Share This Product. FacebookXWhatsAppEmail