Skimming over lath & plaster

[unkle]

Old 1930's house, most of the walls plaster is pretty good/sound.

However ceilings have had repairs over the years, some have been papered and cracks have appeared, what are my options?

Do I have to take them down completely and board with plaster board, or is it possible to just skim them (obviously where papered that would need to come off.

Thanks

 

[roughcaster]

Just because a lath and plaster ceiling has cracks in it, doesn't mean it has to come down or will fall down. Get the paper off, because quite often, paper makes the cracks look far worse than what they are. Get up on a pair of steps and push up on the ceiling,,, all over, you'll soon see if it's sound or not. If it is sound, get a plasterer/s in to give their opinions on skimming and ask for a quote. With a bit of work, they plaster over no problem and look great, keeping the character of the room.

Roughcaster.

 

[joe-90]

Scrim and skim.

 

[JohnD]

have a look at the upper surface of the ceiling from the floor above. If lots of the nibs have broken off, or the laths are in bad condition or the nails rusted, it is not secure.

it is possible to repair a L&P ceiling if the nibs are off and parts are sagging, if it is a fancy ceiling and worth the trouble. I have done it and I am just an amateur.

 

[joe-90]

I remember that post John. Do you have a link to it as I may have to sort a ceiling like that shortly.

 

[JohnD]

no, but...

go upstairs and look at the top surface. pick off or vac up the broken nibs. Vac out the dirt. Make absolutely sure they are no bits between the plaster and the laths. Handle gently so you don't make the plaster fall down.

from underneath, put some large flat boards under the sag and slowly push it upwards. Jack it against the floor so it is pushing the ceiling hard flat against the joists.

go back upstairs and check for anything wrong. If any patches of lath are iffy, nail or screw expanded metal lathing to the joists. It must be open-textured enough that you can pour through it. be aware that hammering might make any unsupported loose bits fall off. you can use a soft brush on the supported patches while you vac them.

mix up a runny finish plaster. pour it over the lathing so it encases it and is lying against the old (clean) plaster. it might be possible to use an open-weave reinforcing fabric, I don't know.

leave it to harden

cross your fingers and (after a day or two) remove the jacks and lower the boards.

it is important the plaster cannot stick to the boards. I used laminated chipboard but if it does not have a non-stick surface you could wrap it in polythene or something.

there might be snots of plaster that has dribbled through cracks and holes. scrape these off. you might need a bit of filler here and there.

the ceiling is now fixed back up and you can redecorate it.

look for any other areas where the nibs are missing (even if it isn't sagging yet) and re-fix them.

if you have those fibrous plaster mouldings, you can lift them up and screw to the joists (even if they have fallen off) and fill any damage. They wil probably originally have been cast and lifted into position before the ceiling was plastered. You can even make them yourself on the bench if you cut a ply profile to run them.

 

[54aardvark]

Thanks JohnD - I do a lot of work in older buildings, never had to deal with this yet but, come the day, I'll remember where I read it.