Old Plaster

[Harris]

I've got a problem with a room which has very old plaster walls, 3 of the walls are brick with plaster, which I'm not too worried about, I've patched some holes and the whole lot feels pretty strong.

The forth wall however is just wooden slates with plaster, and no mater what I do with it, it just feels weak.. (If I push the middle of the wall it bows a bit)

I'm thinking I could fix plaster board to the wall to give it a bit of strength (not sure just how much strength it would give it?), is this a good idea? If so, how do I fix plaster board to a weak wall?

Any ideas???

[BillR]

There will be vertical studs spaced around 2' apart. You can detect the studs easily because of all the nails holding the horizontal lathes. Simply screw the plasterboard to these studs using drywall screws which will have to long enough to go through the old lathe & plaster which will be about 1" thick. I saw this done recently but the plaster was knocked off the lathes first because it was "blown". The lathes were left in place and the plasterboard screwed on top. The result was good, firmer than a modern stud wall..

[Meoww]

I'm presuming that the plaster and laths are what's bowing, not the timber members of the wall itself, which should be quite sturdy.

If they are (sturdy), find one, then sixteen inches away from it should be the next one, and so on and so on. Remove your skirtings, dado rails, picture rails, switches and sockets (if any) and just over-board it with plaster board.

It'll feel a lot firmer but of course it will also need skimming.

[Michael McNeil]

The uprights will be any distance apart if they were put in before regulations controlled studwork. Clear a patch of laths and have a look. Stripping the plaster with or without the laths will be messy. If you stripped the plaster you could plaster over the laths again or add boards to the wickerwork.

Why not try just bonding it to the old wall with plasterboard adhesive?

[Harris]

There are a number of long cracks in the plaster, which means that it bows more than normal in those places....

[William Joones]

I've had this dilema before and tried a couple of things on different walls:

1. Plasterboard over the original plaster. This worked fine - screwed all the way through into the studs. These studs were not vertical though! Be aware of that - whilst you know the location of the studs at the bottom of the wall that doesnt guarentee them being vertical. I used some adhesive as well, just to be on the safe side. I took off the lathes as they were all slightly different depths and I wasnt convinced that that plasterboard would have been truly flush on them.
2. Removing original plaster and lathes. This was very messy. And created so much waste. However I was doing some wiring at the time so it seemed the best option. Plasterboard is really easy to screw into the studs. And you can see where they are too. I had to make a whole load of additional 'studs' (both vertical and hotizontal) as the studs were not uniformally spaced and didnt fit with the standard plasterboard sizes. This was pretty tedious.

All in all, next time I'll plasterboard over the original plaster.

Will