lath ceiling

[noble78]

Hi all! I'm new - please be gentle!!
We have a victorian terraced which has loads of original features including lath and lime plaster ceilings. We have had to take one down as it was beyond repair. The others don't look too bad apart from long hairline cracks. It is still keyed as we checked the loft.
Has anyone repaired a ceiling? What did you do? Did it succeed? Any advice what not to do?
We are trying to avoid pulling them down and I have seen a repair with washers, fibreglass mesh and a lime plaster but don't want to do it if it won't work!

Thanks

 

[Penners]

Welcome to the forum.

Repairing with washers shouldn't be necessary if the plaster is still well keyed to sound laths, which are themselves well fixed to the joists.

I'm no great expert on repairing cracks in lime plaster but I have heard others talking about using Plaster of Paris or even Polyfilla. If I had to do the job, I think I might try the newest type of Polyfilla called "One Fill". It's extremely light and plastic, with a fine texture that should press into cracks quite effectively. If you're only dealing with ceiling cracks I don't think you need to be too precious about the breathability of the fine lines of filler.

 

[malcolm]

Lime and lath ceilings are wonderful things and worth preserving as much as possible. One of ours had a few hundred gallons of water fall through it while we were out. It does have a bit of a crack as a result, but a plasterboard ceiling would have been on the floor.

Otherwise only ones here that are cracked are upstairs ceilings. The loft rafters are too small to walk on but that hasn't stopped people messing around up there. I'm almost tempted to throw some 100mm celotex boards up there to spread the load across several rafters to reduce the chance of damage in that section when plumbers and electricians etc plod around in the future. After that fill the gaps in the ceiling (scrape a bit out then use lime and fine plastering sand, or just rub pollyfiller into the gap) then paint.

 

[Zebra]

For the one that you've had to take down, I'm not sure whether you mean that the plaster is removed but the laths are still there? In which case, haired lime plaster or hemp plaster make a suitable base coat, with a finer lime plaster over the top. Alternatively, if the laths are gone too, you could board the ceiling in woodwool boards and apply a lime plaster to that. Or just go for plasterboard.
Edit: sorry, just re-read your post. I don't think that was the question you were asking, was it......

 

[MatthewC]

I had two of the the upstairs ceilings re-plastered with lime as they were very bad - we kept all the old lath and broke the plaster off from above - very messy! - then repaired the lath as required; then a couple of holes (thanks to the electrician!) were repaired quite successfully with lime as well - just well dampen the edges. Downstairs, however, was plaster boarded over the failing lime, because we only discovered this problem very late in the process and once you do the lime plaster you don't want to tread above it for a long time, which would have affected our moving in date.

I am convinced that the lime upstairs was a good idea as it helps reduce any condensation by being breathable (and we used sheeps wool insulation in the loft as well). Downstairs, of course, is not the same problem. I really do recommend keeping the lime upstairs wherever possible.

Matthew

 

[noble78]

Thanks for all your replies!

I've managed to convince other half and the plasterer to save them

Did not fancy pulling them all down, the one room I did (thankfully the smallest) was horrendous! We took all the weight off it 2 huge steel water tanks, bricks and half a roofs worth of slate too. We part boarded ready for trades so hopefully cracks won't worsen.

We are going to repair the small cracks and top coat lime plaster.