hollow/blown plaster

[Webbit]

Hi,

I'm in the process decorating my downstairs and prepping for plastering. There are a few areas where my plaster work is hollow to the tap, but the actual skim coat surface is sound. My plan is the have walls and ceiling (newly plasterboarded)skimmed and I'll paint on top. Should I be repairing the hollow areas first? It's original plaster work - 1930s house.

Nothing is bulging out and no large cracks, but not a good enough surface to have a paint finish.

Cheers,
Matt

[freecar]

Personally I would want all the plaster sound before a reskimming.

When I decorate I rip out any areas of blown plaster and redo it, sometimes it adds a day or more to the job but I wont paper or paint blown plaster.

That's just me though.

[Gav147]

As above chop it out back to solid plaster and make good before skimming as over time there is a chance it will start to crack.

[shimmey69]

be warned though as it might well be lathe and plaster and you could end up not stopping pulling plaster off until it is all off!! just be careful. as a quick job could end up in weeks of works

[BuzzLightyear]

As above. Definitely cut back to good surface also to ensure the plaster has blown because it's old, not due to a leak / water ingress.
Good luck!

[dickymint]

shimmey69 said:

be warned though as it might well be lathe and plaster and you could end up not stopping pulling plaster off until it is all off!! just be careful. as a quick job could end up in weeks of works

Yep. Do make sure it's not lath and plaster.

[Webbit]

cheers guys, it's the party wall and external wall (solid brick behind). I'll hack it off, i knew that was probably going to be the result...

tied up with plumbing today - why do 5 min jobs turn into a whole days work (!). Been back and forth to the DIY places about 4 times today.

[VxDuncan]

My house is exactly the same - 1930's and most of the plaster is blown. You can patch the bits that are blown, but really the best way is to start from scratch and take it back to the brick.

Quickest way to do this is respirator, goggles, seal the room up and go at it like a madman using a shovel. Seriously. You can ponce around with a scrapper, but a shovel is the quickest way to get rid of that dry, loosely bonded dust that passes for plaster. You can then fix battens and float out with backing plaster after cleaning up and sealing the wall with PVA.

Another reason for doing this is if you have lots of noise coming through the party wall. My house is missing the odd brick in the party wall where they were left out for staging boards (like scaffolding). The bricks should be filled in afterwards, but mine never were. Basically between my house and next door there was two pieces of plaster board. Bricks now replaces and much quieter!

If you go the patch approach, always check behind the radiators as I've found it's always blown behind them in my house.