Removing Plaster Board Used As Overboard Onto An Original Lath Ceiling

[jfulltho]

Hi There
We are currently renovating an upstairs bedroom which is in a Georgian section of the property that we own. The original Property is a Grade II Listed Timber Framed house which is semi detached and adjoining the property is a one up one down brick built section which we believe to be Georgian.
During the start of the renovation we have to our delight revealed the original Elm floor boards that had been covered over with thin plywood. However, whilst we were having some electrical work carried out we noticed that that the original lath and plaster ceiling has been boarded over with plaster board. I have tried to find out if anyone has ever tried to 'carefully' remove the plaster board without damaging the plaster and the laths directly underneath. I have read various sources on the internet where people have removed the lath and plaster ceiling altogether (although I cannot understand why you would want to?) and replace with gypsum but I have not come across anyone who has tried to carry out this work. I am a practical person and I do appreciate that I am probably trying to create more work for ourselves but has anybody actually done this during the renovation of their period property?
If anyone has any experience of this then I would be grateful for some advice? I am aware that anything to do with ceilings can be extremely messy and I am not trying to remove the original ceiling altogether albeit using crow bars. It is just if there is a way that the plaster board could be removed 'carefully' would be useful. The rest of the property has managed to retain the original lath ceilings as well but they have used lining paper over the lime plaster. Another job eventually, but the lime ceiling with its quirks is nice to see why would any one want to cover them up.

Thanks

 

[88v8]

Hello and welcome.

Yes, the subtle and not so subtle undulations of original ceilings can be a pleasure. To some people. Us, of course.

Over time, plaster can lose its grip on the lath.
Bomb damage from WWII was an issue in my previous house.
Or perhaps there has been an upstairs plumbing woopsy.
Or perhaps the lath is woodwormed.
At any rate, once the nibs begin to break, there is the potential for patches of plaster to come loose, and patches of plaster begin to sag. Rather than suffer the dust - a lot of dust- of taking it all down, plasterboard & skim is a quick fix for someone who cares nothing for originality and wouldn't know subtlety if it fell on them.

If the cracking is not too bad it can be stabilised with reinforced lining paper; I put three criss-crossed layers of scrim paper on the bedroom ceiling of our previous house, complete success, no more cracks.

Whatever the cause, I would guess that your ceiling has started to come away from the lath. Perhaps some of it has already fallen or been taken down.

There are ways of securing loose plaster ceilings. I cannot shed light on them because it's not something I've ever had to do.

The plasterboard is likely to be nailed on. Or perhaps screwed, but I would bet it's nailed. Poke around with an old screwdriver in a corner or under a joist, chip away the skim until you find a fixing. If it's screwed, then bingo.

The you'll have to uncover all the fixings by poking.
Or, more intelligently, with this
http://www.rutlands.co.uk/sp+woodworking-hand-tools-measuring-metal-detectors-little-wizard-metal-detector+24902
(money spent on tools is never wasted).

One way to get nailed board off without more damage to the plaster is to use a hole saw and carefully drill around each nail, thus disconnecting the board from its support. Obviously, don't drill through into the underlying plaster.
Need I say that plaster board is bloomng heavy, you'll need some props to hold it up while you unsecure it. And a dust mask.
And a hair net. if you have hair of course, one mustn't be hairist.

Be prepared for a degree of disappointment as to the condition of the original ceiling. That plaster board is there for a reason. But a good plasterer can repair or indeed remake the original two-coat work.

Ivor

 

[plasticpigeon]

I would leave it if it looks ok. I'm sure that the act of screwing or nailing the plasterboard up will have cracked the original plaster badly, and once the nibs break off the plaster it is free to fall off the laths. I'm sure the laths will be fine, but the repair work will be a nightmare. I have to admit to overboarding ine my place where the plaster was very cracked and delaminated. I've got to choose my battles wisely!!! My ceilings are just flat so there was no period detail lost and at least the laths are still there!!

 

[TheRoost]

Our front bedroom has had its lath ceiling pulled down at some point, but the other bedrooms have been over boarded like yours. Can you get into the loft and inspect how well the old plaster is attached to the laths? some of ours is quite brittle and is just piles of rubble in places, but I guess this could of been abuse from roof workers when they completely re-laid the roof years prior.

DIY bodgers love to boast about how they pulled down an old ceiling. I've only one word for them! My ceilings are now 40mm thick which meant I had to go and find longer screws for installing plaster roses, and mess about with blocks of wood for the supplied brass ceiling hook screws to bite into, grrr!
Good luck.

 

[agbagb]

Magnet to find the fixings, dig around to get under the clout heads, pry them out. Prop the boards up before you've pulled too many out!

 

[jfulltho]

Ivor

Thank you for taking the time to read my enquiry with relation to our bedroom ceiling and responding with some useful suggestions. I had thought about using a hole saw and your suggestion regarding finding each screw or nail is something that I did also consider. In order for this work to be carried out carefully then you have no alternative than to remove it in this way however, time consuming that it might be, but if the lath ceiling underneath is in a good state of repair then it will be worth it in the end and it will help the room to breathe. The walls unfortunately are gypsum as well but that is for another discussion although I know what I need to do with that.

I have been reading an amusing / witty 'blog' on our surveyor's website that we used of a guy who has painstakingly scraped artex from a ceiling to reveal the original ceiling. Fair play to this guy, it has taken him forever, but the reward has been their. (fortunately for him this did not contain any asbestos either)

But in terms of removal and repair of the existing ceiling, depending upon its condition, you did mention two coats of lime plaster, one scratch coat, one finish would be enough I assume? Although I am sure that I read somewhere on this forum to do with another enquiry regarding ceilings and a member did suggest using lime hemp plaster as a backing coat before applying a coat of lime plaster (finishing coat) over the hemp. At the end of the day the ceiling does not need to be a smooth finish, I know that the ceiling in the dining room immediately below this one has the original lime ceiling left which fortunately has not been boarded with gypsum. This has a nice warm appeal about it which is another reason as to why I was considering the removal of the plasterboard in our bedroom. I should mention that our surveyor did suggest it too during the survey.

Anyway thanks again and I will give it some serious consideration.

Regards

 

[MatthewC]

Rather than suffer the dust - a lot of dust- of taking it all down, plasterboard & skim is a quick fix for someone who cares nothing for originality and wouldn't know subtlety if it fell on them.

You mean a REALLY AWFUL INCREDIBLE LOT of dust that gets EVERYWHERE - been there, done it. See the end of http://houseintheenchantedforest.blogspot.co.uk/2010/12/getting-to-know-neighbours.html

I'm sure the laths will be fine

if you've had water ingress in the loft (as my house did), don't bank on it! They can look OK whilst actually having very little strength.

 

[Flyfisher]

Welcome to the forum.

Whether you should or shouldn't remove the plaster board is clearly a personal decision. All I would suggest is to make the decision with the full understanding that it could easily turn into a major job, if not the replacement of the entire ceiling.

There is probably a good reason why the plasterboard was fitted in the first place and my guess is that it would have been because of a partial failure of the original lath & plaster ceiling. We have one bedroom in which the original ceiling has badly failed, primarily due to decades of rain and damp from a poorly functioning roof causing the fixing nails to rust away to the point where they could no longer hold the laths & plaster in place. In some places the ceiling has actually collapsed and in other places merely detached and sagging. Add a huge amount of detritus sitting on top of the ceiling into the mix (the abundance of walnut shells - yes, we have a mature walnut tree in the garden - suggests that the squirrels have been living very well over the years!) and it becomes almost impossible to fix the ceiling back into place without causing even more damage, so the lumps and bumps can be somewhat extreme in places.

It's probable that the plasterboard can be removed fairly easily using the good suggestions above and of course it's possible that the underlying original lath & plaster is in good condition and requiring only minor repairs - but be prepared for the worst and you won't be disappointed, and if you are not able to deal with the worst, for whatever reason, then it may be best to leave well alone.

Incidentally, on the subject of undulating original ceilings being a prized period feature, I suspect they are only undulating precisely because they are in the process of failing (for the reasons described above) and I cannot believe that craftsmen of old were incapable of creating a perfectly smooth, flat finish to their plasterwork. Indeed, I'm sure they would likely have been horrified to have plastered anything so 'badly' in the first place. Sometimes, even using traditional materials and methods can only recreate the original as it was centuries ago - which of course would have been 'brand new' back then, just as a recreation of it would be today.