render or bonding plaster to smooth off reveals priop to drylining...

[Tom Dixon]

Currently dry-lining my old cottage, rubble / masonry walls. For most of the walls I am putting insulation against wall held in place by stud-work. However I need to glue / fix 20 mm insulation board and plaster board directly onto the uneven reveals, and my feeling is that they are sufficiently uneven that I need to smooth them off, to offer a good surface to accept insultion etc. to provice a good level finish. I was going to render, but having never plastered I'm not sure what bonding plaster is good for - would this be useful stuff to smooth off surface and bond with the insulation board? Any advice out there?

Cheers, Tom

[Andrew Gabriel]

Bonding plaster is a plaster undercoat that also sticks well to almost everything (tools in particular;-). You should be able to get it smooth, although not smooth as finish coat as it contains some larger pieces (which would also mean it wouldn't work in a thin layer).

However, it isn't waterproof. It will sock up water, and prolonged or repeated exposure causes it to fall apart. If you want something which will survive in the presence of damp, then you should use sand and cement with a waterproofer. You could also add a small amount of exterior/waterproof PVA into the mix.

I don't have a completely clear picture of what you are doing, so I'm not sure if this is helpful or not.

[chris French]

In message , Andrew Gabriel writes

I read it that the OP wants to smooth off the internal window reveals enough so that they can stick the insulation /plasterboard to it.

I would have thought bonding would be fine here, but I'd probably use sand /cement

[Tom Dixon]

Sorry if my original post wasn't clear - last post had it right, and I've decided to go with a render. Thanks for replies and advice - Tom