DIY Doctor UK DIY Forums

I've got a brick utility room wall that connects my utility to my neighbours utility (even though I'm semi detatched on the other side). I had some damp where there was an issue with the guttering between our utility roofs which has now been resolved by replacing the guttering and my roof has now been tiled. Some of the mortar got damp and I've wire brushed it all out which has left it looking a bit untidy. I'm only about 5mm deep however so don't think it's deep enough for repointing, plus it would take me ages as it's a 30ft * 8ft wall.

I am planning on dry lining the wall but want to keep the plasterboard as close as possible to the original wall due to door frames being against that wall so I need to only come out 30mm max from the existing wall. Looking at the advice on using battens it seems to recommend 25mm battens which would be too thick for what I'm after by the time I put boards on too. If I batten using something like 12mm will I get problems with condensation behind the boards? I could dot and dab also but thought battening would give me a much better chance of getting everything square and the boards all level with each other to provide a smooth finish. The bricks are also painted with masonary paint which I have PVA seeled after wire brushing so not sure if this would effect the adhesive if I dot and dab.

Any advice appreciated.

paint the wall with bitumin paint 2/3 coats this will prevent damp.On the last coat of buitumin throw coarse sand on it. When its dry it will provide a key for your drywall to adhere to.

Thanks for that, doesn't using PVA prevent damp also?

If I use bitumen and sand and then dot / dab my boards up there, what is the minimum distance between the boards and the wall to avoid condensation forming and causing issues?

PVA will NOT seal out the damp. quite the opposite, the damp will liven up the PVA and turn it back into liquid glue. do as welsh brickie says, better still ensure that the cause of the damp has been fixed.

you can use foilbacked plasterboard this will aid in insulating, but seeing as your tanking the walls damp should not be an issue .As your tight for space the drywall adhesive can be 10mm thick but can be as thick as 50mm.Pva wont work as its a bonding agent and not really used as a waterproof coating.
You must keep the boards 20mm free from the floor though to stop damp sucking into the boards.