Repair Lath and Plaster ceilings using ceiling buttons

[chrisjashton]

Hi all

I am in the early stages of renovating our late victorian house.

We have lots of lath and plaster ceilings in half reasonable condition but with plenty of large cracks and patches where it feels loose.

I was wondering if anyone has any experience of using ceiling buttons/marmox/wedi washers to reinforce the ceiling prior to repair? I found two videos on youtube, both from the USA. One example is here : http://www.youtube.com/watch?v=qYSQBH5rbmU

I am planning on reinforcing it generally and particularly around cracked/loose sections prior to a skim with some sort of lime plaster top coat.

Has anyone tried this or does anyone think it is a bad idea?

Many thanks

Chris

 

[MatthewC]

Welcome to the forum, Chris.

Interesting idea. What are the buttons made of? They look galvanised; I have been told that anything galvanised (like the mesh use by plasterers) does not last when in contact with lime (but I don't know if that means it only lasts two years or two hundred).

Also, how good are the laths? It looks as though on the video the button is just screwed in anywhere; I wouldn't want to trust the old laths to take the weight if it was dampness which caused the plaster to start to fail, as the laths may be rotting and won't hold the screw for long. To be sure, you would need to locate the joists to screw into, but they could be difficult to find.

The other question is just how large are the damaged parts of the ceiling? If they are extensive with heavy cracking then I would think you might be wasting your time. I pulled down two whole ceilings as there were so many holes in them (due to water), and then replaced almost half the laths before new plaster was put up. It is possible to do patch repairs to ceilings (like where my electrician's lad put a foot through!) provided you are very careful when cutting out the damaged parts so that you don't cause the attached plaster to become loose; if you then have to replace laths, you have to drill and screw them not nail them.

Looking forward to photos...

Matthew

 

[Nigel Watts]

About 10 years ago our builder used a similar technique to secure the ceiling in our bedroom. In our case I think the buttons were screwed into the joists rather then the laths and were recessed rather more than in the Youtube clip. I believe stainless steel was used. The ceiling is still there and there is no new cracking.

 

[Keith Bowman]

I can't comment on the buttons, but you ought to be able to trace the line of the joists with a metal detector picking up the nails.

 

[chrisjashton]

Thank you Matthew

The buttons on the video are metal, you can buy galvanised ones but I have actually gone for plastic ones, hoping they are more 'inert' and I plan to paint/prime them once in to assist adhesion.

That video does seem to show him screwing into the laths but I'm planning on finding the studs as you suggest. It is the lath and plaster I think I need to support, not so much the plaster TO the lath if that makes sense.

I think the laths are reasonably good condition, no signs of water ingress, just sagging from age. The ceiling is sagging and the cracks are big but I think it is all holding together reasonably well so I am hopeful this technique could save it for some years to come. It would be interesting to find out if anyone else has tried it. It's the only way I can think of to preserve the original ceiling and ensure it is strong enough to take a skim coat of lime plaster.

The only other thing that occurred to me, and again, it would be interesting to know if anyone has tried it is to insert a second beam half way across the room to halve the span of the joists. This is one of the top rooms with no cornice or anything so there is no decorative finish to lose and I guess I could make it look like it is 'meant' to be there though it would leave the room looking more 'farmhouse' like than a late Victorian room is supposed to.

I'll try to post some photos in a week or so when I have finished scraping off the stipple which is the bane of my life.

Thanks again

Chris

 

[88v8]

There are actually thingummies called Stud Detectors, which are jolly useful if you're looking for strongpoints in wall or ceiling to take a fastening or light fitting.
Sorry to send you here, other vendors are available.
http://www.amazon.co.uk/s/?ie=UTF8&keywords=stud+detector&tag=googhydr-21&index=diy&hvadid=9030516305&hvpos=1t2&hvexid=&hvnetw=g&hvrand=1892681698182828244&hvpone=&hvptwo=&hvqmt=b&ref=pd_sl_51ye2nfi17_b

In a lath ceiling, you have to take a few runs across the likely line of the joists to ensure you aren't picking up the lathes.

Ivor

 

[middi]

Hi and welcome.

Of course you can use anything that will "tack" and hold the existing or old laths into position and then re-plaster over the top.
I have found that if these " Victorian" ceilings are in bad shape, be it old laths drifting away from floor joists due to rotting or disentegrated rusty nails or possibly the original plaster just becoming adrift from the laths due to disturbments and/or vibrations the best, quickest and much safer solution is to identify and mark the ceiling joists direction and by using long plasterboard screws attach modern plasterboard sheets over the existing plaster and laths into the joists and then replaster.
This will eliminate any doubts about the structural integrity of the " unrepaired" ceiling or the nightmare possibility of limewash or distemper being previously used as this has to be removed before plastering. Also no original fabric will be destroyed.

Jiust an alternative suggestion to overcome your problem.

Middi

 

[plasticpigeon]

I am in a similar situation to you, and have found that the laths are good in my house but in some places the nibs of plaster that squeeze through the laths have broken off leaving parts of the plaster unsupported. I believe this is because of structural movement and particularly upstairs, because the ceiling joists are very thin (only 3 x 2 although spaced very closely, at around 18") and therefore sag over time. I was wondering if lifting the unsupported bits of ceiling from below and tieing in from above might be good. I'm sure the very very knowledgeable Doug (DJH) detailed a method like this using wire round the laths and plaster of Paris to secure them that sounded good. I think I will attempt this method and try and make good on the other side, and put lining paper up. Sorry I don't have practical experience to share.

 

[Nigel Watts]

attach modern plasterboard sheets over the existing plaster and laths ... and then replaster.

I wouldn't do this, especially if there is a cornice. Better to repair or replaster in lime in my opinion.