Ply for a ceiling instead of plasterboard.

[jim_hanna]

I have to reinstate a small area of ceiling(about 10 square ft) following a roof leak. I’ve never worked with plasterboard but I have plenty of ply. I was planning to use a ply base and prime it with a PVA wash for my plastering attempts. It’s a textured ceiling which should help to conceal the joins.

My question is are there pitfalls to using plaster on top of ply, is swelling or delamination a risk?

Jim

 

[kostello]

Plaster probably won't stick....... And plasterboard is cheap

 

[Harry 48]

Plastering on ply will not work ply moves with moisture in the air plaster does not in time the plaster will fall of also ply will not meet fire reg's

 

[Scottdimelow]

If you can work with ply you can work with plasterboard, all you need is a stanley knife

 

[HexusOdy]

If you can work with ply you can work with plasterboard, all you need is a stanley knife

Like the man said, nothing easier to size than plasterboard and it's not expensive. Probably only take 1 sheet for what you need which should be less than £10.

 

[Fromey]

I'm not sure about the level of movement of ply (it's made that way to be stable), but I think there might be something in the fire regulations point of Harry's. Probably something you don't need to worry about, until you discover it null and voids your house insurance!

 

[dickm]

Getting plaster to stick on plywood would probably be a bit of a faff, but can't actually see why it would be a fire hazard. After all, ceilings used to be plastered on to highly flammable softwood laths. Or are insurance companies now going to wriggle out of payment if you have a fire with an old ceiling? (I wouldn't put it past them )

 

[Harry 48]

Getting plaster to stick on plywood would probably be a bit of a faff, but can't actually see why it would be a fire hazard. After all, ceilings used to be plastered on to highly flammable softwood laths. Or are insurance companies now going to wriggle out of payment if you have a fire with an old ceiling? (I wouldn't put it past them )

Plaster on laths does not stick to the wood but is held on by the key that go's through the space's between the laths
12.5mm plasterboard is building reg's on ceilings but if it is a repair like for like is acceptable. Ply will not give you half an hour fire rating and the insurance company not be happy.
(hammer)

 

[jim_hanna]

Many thanks for all the replies and for putting me on the right track. I would never have imagined that building regs would be a factor in a repairing a small ceiling hole. I’ve spent the weekend tracking down the leak source (flashing round a Velux window) and patching the hole, 9.5mm plasterboard to match the original. It was indeed easy to cut and shape the plasterboard, what I hadn’t anticipated was the difficulty of working overhead with even a third sheet, trying to hold with one hand and screw with the other was impossible. SWMBO is only 5 foot tall so I had to buy a drywall extension support rod. Another essential was a shrouded bit for the drywall screws.

Less than £ 80 for the various materials and tools to fix, including the leak repair bits, so I'm well pleased. I dread to think what a builder would have charged.

Thanks

Jim

 

[andersonec]

what I hadn’t anticipated was the difficulty of working overhead with even a third sheet, trying to hold with one hand and screw with the other was impossible. SWMBO is only 5 foot tall so I had to buy a drywall extension support rod.

Jim

An upside down broom and a piece of that ply you've got would have sufficed.

Andy

 

[jim_hanna]

what I hadn’t anticipated was the difficulty of working overhead with even a third sheet, trying to hold with one hand and screw with the other was impossible. SWMBO is only 5 foot tall so I had to buy a drywall extension support rod.

Jim

An upside down broom and a piece of that ply you've got would have sufficed.

Andy

At only £15 in B&Q for the extension rod I think the wife was quite happy to pay that so that she didn't have to stand with a broom.