Separated lime plaster ceiling - treat the same as a modern one?

[Andrew Collins]

I have a lathe and plaster ceiling in my upstairs hallway that's started coming away from the lathes. Now I know how to handle this with a modern ceiling, but this one is 100 years old and made with lime plaster. If the walls are anything to go by, it will be pretty crumbly, too.

I'm thinking of jacking it back into place, then giving it a liberal dose of PVA solution to try to stop it crumbling before attempting to stick it there with gauze and plaster of paris.

Does this sound reasonable? I would replace the ceiling, but I'm no plasterer and here in Hull anyone who is is booked up for eternity.

Ta!

[Mark]

Options in order of easiness and least mess:

1.You could try screwing it back into place, or use large headed clout nails

1. You could counterbatten ( 2 by 1 battens at right angles to joists) board and skim.

2. You could rip it all down, board and skim.

mark

[pablomartin]

I would think if the area is small on a large ceiling you should carefully cut out the damaged area and repair it but becarefull the plaster is very dry and does not take to being disturbed.

If it is a large area I would leave the ceiling alone and overboard it but this may affect any cornise you may have.

Pablo

[meow2222]

Standard thing is to jack it back up, using a load spreading sheet, and pour pva onto it frm above to glue it back. Then its just a crack fill.

Recessed screws and penny washers can also be used if access above is just not an option, but pvs is to be preferred where poss.

NT

[Andrew Collins]

[snip, suffice to say that it's lime plaster]

I don't think it's up to that. If it's anything like the walls it will only be the top coat that's holding it together. I'm fortunate enough to have access to the back of the separated areas, though, which makes my life a bit easier.

No, really, *I* couldn't. I'm hopeless with a float. Been there, done that, had to call a professional to fix it. Unfortunately since the floods all the plasterers here are either booked up forever or are charging stupid money.

This would be my preferred option, if I could actually *get* a plasterer to finish it for me.

[Andrew Collins]

Neat pva, or a solution? I'd be worried that neat PVA might be too viscose to penetrate the lime plaster far enough to give a good hold. I guess I could always do it in 2 stages though.

Cheers!

[Mark]

You are more likely to get a plasterer if its all nicely boarded and ready to go. Plasterers like plasterering. They don't like ripping down old ceilings or boarding. I suggest you get it all ready to skim and then it'll be a lot easier to get a plasterer.

mark

[mail]

Dear Andrew Done this often Posts suggesting localised screwing etc are right Avoid ferrous fixings if possible unless stainless Use SBR not PVA (pva can re-emulsify if wet) Use casting plaster (if necessary mixed with lime putty - in tubs) to delay the set but casting should be ok Consider galvanised or Stainless EML on the top of the laths first tacked to side of CJoists in a U shape for strengh Bully for you for saving a ceiling not ripping it down William Morries Ruskin et al would be proud of you! Chris G

[Lobster]

Care - not necessarily. For sure, nobody likes ripping doen old ceilings, but as for boarding, some plasterers really don't like skimming a ceiling boarded by someone else. eg, some plasterers wil tell you that adjacent boards should be butted tightly up against each other, others will say there should be a few mm gap to allow plaster through to form a 'nib' behind. Also, in an old house, plasterers know that the ceiling joists are often very uneven, and they may think a d-i-yer won't have packed the boards out where necessary to correct for this.

Trouble is, if you rip the old ceiling down yourself before the plasterer comes, if he's boarding too you could end up with a significant lag time with no ceiling at all, whereas a boarded, unskimmed ceiling is reasonably acceptable in the medium term (been there done that...)

David

[John Rumm]

Use taper edge boards, and scrim and joint fill instead. Needs a final sand, but you will get spot on results without needing to be able to skim.

[Lobster]

FYI this is easy to do without special kit etc - get yourself a couple of lengths of 2x1 timber and cut them to about 1" longer than the ceiling height of your room, hold a board up against the ceiling and then wedge it there using your 2x1s. You can apply a substantial upward force that way.

A solution - say 1:4? And vaccum the area first to get rid of dust etc.

I've done this myself with a lath and plaster wall suffering from the same problem, worked a treat.

In addition to that, while you've got the ceiling jacked up and PVA'd, another trick is to apply some bonding plaster to the reverse side of the ceiling over the area where it's coming down, that will hopefully bond the whole lot back together.

It's worked for me - again, in walls rather than ceilings - but it's definitely a bodge rather than a proper job. However, hopefully it will wring a few more years' life out of your ceiling, at least until such time as the local plasterers have finished their backlog of flood repairs.

David

[meow2222]

Is it a bodge? It gives better noise reduction than a new boarded ceiling, it restores the original means by which the ceiling was fixed in place if plaster is poured, and its recommended by restorers. I cant think of a better way to do it.

NT

[John Rumm]

[Lobster]

[John Rumm]

You can plane down the height at the flat edge with a surform. create your own taper.

[<me9]

You then lose the strength of the paper face, unless you tape over it, then you are back to the bump.

[John Rumm]

Strength is not so much of a problem on a ceiling. If you use fibreglass scrim tape you still get a reasonably strong join even without the paper.

[<me9]

True if your room is less than 8' wide. otherwise you would have to tape and fill over a flat join, resulting in a (slight) bump. Putting the long edges paralell to the window minimises the visibility of these bumps.

I'd advise 3' boards, rather than 4' ones, despite there being more joints, they are easier to lift and manouver by one person. I use 2 poles of 2x2 with a cross piece on one end of floorboard to support and wedge the board whilst fitting.

Shame the bath overflow leaked, It's ruined my best handiwork in the kitchen. I don't fancy doing it again.