type of plaster for damp brick wall?

travel_freak

Hi,

Apologies as I'm sure someone has answered this Q before but I have a damp external wall which is drying out.

Inside, I have hacked off the plaster that was on the wall so it's back to bare brick.

My question is what do I need to use to plaster again properly on the inside?

My builder has suggested just sand and cement but another builder who came along was talking about some waterproof something or other but I can't recall exactly what he said.

It's a Victorian house so thickish, non cavity walls.

I'd really like to get it right this time round and don't want the damp to start coming back through the plaster again.

Many thx in advance for any advice.

myrnahaz

Provided you've sorted out the damp poblem then it shouldn't affect the new plaster (if you haven't got rid of the source of the damp then you'll always have a problem). If you want to be sure, you could always paint over the bare bricks with a sealant before plastering. You should be able to get this from a builders merchants - or B&Q.

Ionkontrol

Sand and cement, then plaster finish.

owls

If it has damp then it will require a coating of cement slurry with a binding agent such as SBR[a rubber based sealant] sand and cement render with SBR added then a lime renovating plaster after, dont use gypsum plaster.the renovating plaster is to allow the wall to breathe.damp can stay in the solid wall for a long time even if the initial problem has been solved.

id get quotes of plasterers as i wouldnt advise a novice to undertake it,if they didnt know what they were doing.

travel_freak

Hi

Many thanks for the replies.

Owls - what is "SBR". I went into B&Q today and asked them for this but got a blank look and no advice - please could you give me any further info on what this is called in the likes of B&Q etc., so I can buy some?

Also, please do you know how much of this stuff should go into the mix?

And roughly how thick should this covering be on the wall?

Should the wall itself have PVA applied to it first?

Many thanks again.

Regards.

paintpot

Hi Travelfreak

I am interested to know if you have done anything other than hacking the plaster off and replastering. I have recently refurbed a Victorian house, similar problem to yours with a very damp wall and it was all hacked off and replastered in a specilaist plaster but I do not know what off the top of my head (I posted a thread on here and received lots of advice). All was well, regularly checked it (it's a rental property and has been empty) until two weeks ago after torrential rain there was a hand side damp patch again in the middle of the wall :eek: It's just been tenanted and the patch came through a couple of days before the tenant moved in so I am not optimistic

benood

Are you sure that the damp was rising/penetrating and not condensation? If it was condensation you will probably find the problem recurs unless you can either reduce humidity or warm the walls up.