I've had some damp proofing done in my property last week. They used a chemical DPC, rendered with a sand and cement mix with waterproofer and skimmed over the top. The problem is the quality of the top coat is awful. The company have come back and just sanded loads of places, so of course it still looks awful. Short of getting them to rip the whole thing of and start again (which they've told me they won't do) it seems like the best option is to reskim the whole thing. I've been told it needs to dry for 6 month before it can be painted and even then I should only use trade emulsion with no vinyl. As reskimming it would need the walls to be pva'd I'm worried this will just seal the walls so the render and plaster won't dry out properly. Any recommendations on the best approach to resolve it?