Applying plasterboard to painted bricks

[chocworks]

Hi,

I'm a first timer on this site and have found the info very helpful. Further to the assistance given regarding applying plasterboard to a brick wall in one of the current threads, what is the impact of the bricks being painted. Can the plasterboard be applied straight onto a painted brick surface or should the bricks be stripped and cleaned?

Thanks.

[seriph1]

Hiya


I would be asking a plasterer for confirmation but imagine that provided there was enough to key the adhesive into the wall, say along mortar courses all should be ok


Success

[ndru]

Can't speak for plaster but I once had to render an external painted brick wall. I think you'll first need to render your brickwork as a key for the plaster anyway.

Our rendering contractor advised me to strip or etch as much of the paint off as possible to assist render adhesion. We used ordinary paint stripper and water jet. DON'T take this approach - the water jet will leave a terrible mess in your yard and your neigbour's yard too, not to mention the impact on stormwater! Sandblasting is another possible, albeit expensive approach but best done by someone who knows how to use the relevant equipment.

After we removed most of the paint from the bricks our contractor added PVA glue to the render to help it stick to the wall.

[silentC]

Don't know much about your situation there but if it was me, I'd be fixing timber battens to the bricks first then fixing the plaster to that... May not be necessary but it removes the guesswork and it will take care of any lumps and bumps in the brickwork.

[ndru]

A variation on that provided by the Big Coight could be to attach a metal lath (mesh) to the wall or to wall battens and render+plaster on top of that.

[silentC]

Or you could just stop at the render and paint that... Who needs to fiddle with tape and jointing compound when you've got a rendered wall to paint?

[ndru]

Oops - I should look more closely at the question - thought he was asking about plaster, not plasterboard. Agreed - just stop at the battens. Avoids the ugly job of stripping paint.

[journeyman Mick]

Chocworks,
It might be worth your while to contact the manufacturer for advice (Boral, CSR, LaFarge). I've had a look thru the Australian Domestic Construction Manual and all the tech data sheets I have, And although there's plenty of info on direct bonding it to masonry walls they all assume that they're new walls. I'm guessing that cornice cement is not going to work too well as it's not going to "suck" into the non-porous painted surface. Wallboard adhesive may work but I wouldn't want to chance it without checking first.

Mick

[chocworks]

Thanks Mick - that sounds like good advice. Have contacted Boral and CSR and I'll see what they say. Would like to avoid having to put battens up if I can. Apart from the time, I don't really want to shrink the rooms any.

Thanks

[silentC]

Stud adhesive sticks to paint real well but keep in mind that the bond will only be as good as the bond between the paint and the bricks.

The other day I saw a bit of plasterboard with a blob of stud adhesive on the back that has a nice oval shaped layer of paint firmly stuck to it.

See what the guys at Boral or CSR say but be prepared to spend a bit of time on it to do a good job. Sometimes quick fixes aren't worth the pain in the long run. Unless you're fixing it up to sell it.

[russ34]

a few yrs ago when i lined a painted block wall with plasterboard, the plasterer asked me to use a 4 in grinder and masonary wheel to remove the paint to ensure the glue stuck directly to the wall. but not the entire wall, just the spots where he wanted to apply the glue... the dozens of ground spots ended up real smooth and shiny but he told me not to be concerned and that the glue would stick fantastic to those smooth spots and eliminate the worry of how well the paint was stuck to the wall.........russ