Page 1 of 1

Posted: Sun Apr 17, 2011 10:48 am
by peg basher
Ive got a job which has two existing masonry dwarf walls that require rendering and painting just to bring them in with a new wall. They are both retaining ground behind them and so are likely to be damp. Any ideas for a mix design for the render? there is also a section of render on the rear of the property that will require patching. Could this be a different mix design?

Posted: Mon Apr 18, 2011 8:32 pm
by mike builder/landscaper
as a general guide we would pva the wall to start then put a first coat on (scratch coat) of 4 to 1 rendering sand and cement and the following day put a top coat of 5 to 1 on top but that is only a general guide. maybe a glug of sbr in there aswell. hope this helps.

Posted: Tue Apr 19, 2011 8:28 pm
by DNgroundworks
The same as above but id bond the wall first with SBR not PVA.

Posted: Sun May 15, 2011 12:31 pm
by simeonronacrete
Clean the surface.

Rake out mortar joints to give a mechanical key for the render to grab into.

Damo with water, then prime and apply Ronafix render.

Posted: Sun May 15, 2011 12:35 pm
by local patios and driveway
simeon, would the building inspector approve that method?

Posted: Sun May 15, 2011 12:37 pm
by simeonronacrete
I cant give a categoric yes, but if he said No I'd be happy to talk to him and find out why.

We've been making such recommendations for 40+ years without too many objections.

Posted: Sun May 15, 2011 12:38 pm
by local patios and driveway
wtf? this post was put on the footings thread. how did it end up here?

Posted: Sun May 15, 2011 12:39 pm
by simeonronacrete
No idea, but the two recommendations I've just given for footings and render should satisfy BCO.

Posted: Sun May 15, 2011 12:49 pm
by local patios and driveway
lol thanks i will bear that in mind if it comes up in future.