DIY Doctor UK DIY Forums

Hi,

I recently had a new damp proof applied to an internal wall and in order to have the damp proof done I had to remove the old plaster/concrete down to the brick work.

I plan to re-concrete this at the weekend and was hoping for some useful tips.

What kind of mix ratio should I use?
The engineer who done the damp proofing suggested using a 4:1 mix with a water proofer as well?
How do I stop cracks appearing?
Do I need to do anything to the exposed brick work prior to adding the concrete? (e.g. wet the walls?)

Thanks for any tips,
Graham

Pva the area first and then "dub out" the wall (fill any deep voids e.g mortar joins, broken bricks). Allow to dry and then do a full coat of render adding the waterproofer. All this should be done with the reccommended 4-1 mix, once semi dry key the surface. Then add a top coat of render once dry, but make this coat a 5-1 mix to avoid cracking.