Bulge in Basement ceiling

[porter]

I have an apartment in a Victorian house with an ancillery room in the basement.
Above the basement is a car parking area for 1 car, (which I can do nothing about)
A bulge has developed in the ceiling of the basement ancillery room.
I have contacted 2 contractors who have come up with widely different proposals for investigation and repair
Any ideas, or suggestions, on how I can investigate cause of bulge and repair?

 

[Penners]

Can you make out what the construction of the ceiling is? A bulge in a Victorian ceiling immediately makes me suspect lath-and-plaster.

If that is the case, then in all probability one of two things has happened:-

1. The wooden laths have started to pull away from the joists to which they are/were nailed - either due to rot/infestation in the laths, or to nail fatique.

2. The plaster has started to part company from the laths, because its key has failed.

So, the first thing you have to establish is whether this is, indeed, an L&P ceiling. The best way to do this is to break away a small area of the material - a couple of square inches or so. Is it a crumbly plaster-like material - perhaps with a fibrous content? Can you see/feel strips of wood within it or above it?

Or is all the above wrong, and the material is actually plasterboard?

Before I go any further, let's see your response to those questions. Then we can go to the next stage.

By the way, if you know how to post one, a photo would be helpful.

 

[porter]

Thanks Penners for your response; It is an L&P ceiling

 

[Penners]

OK. The problem of the laths pulling away from the joists is easier to sort out than the plaster key having failed - provided the laths are in a fairly good condition.

Rather than trying to explain all the details and possibilities, I'm going to suggest that you download the following PDF. Pages 4 - 9 have some good information on the whole business of repairing old lath and/or plaster structures.

http://www.nfdc.gov.uk/media/adobe/PlastersandRenders.pdf

However, if your laths are rotten or infested beyond saving, then I'm afraid you don't have much choice but to replace the ceiling - or, to be really conservation minded, you could leave it all in situ and secure a new plasterboard ceiling underneath it, passing plasterboard screws through the L&P and into the joists.

The one issue that we haven't touched on is the cause of this rot/infestation/nail fatigue or whatever it turns out to be. Given that the room is in a basement room underneath (if I've understood correctly) an external car parking area, there's every reason to suspect a damp problem.

And of course, if you do install a new ceiling by whatever method without curing the damp problem, then it's only going to deteriorate once again, sooner or later.

As I said above, photos and a more detailed description of the structure/location would help.

 

[Hatster]

My parents just repaired their bulging ceiling - investigation showed the lath nails were going, and the laths were pulling away from the joists. My dad screwed them back himself, and then did some general repairs - it doesn't seem to have been a particularly difficult job at all.

 

[Lime]

I think the important thing to do first is find out what is bulging/bowing.
If the laths are breaking away they can be repaired, as said previously, or replaced if required.
However if the actual beams or whatever is holding up the laths are bent/bowing I'd be worried.

 

[porter]

Thank you all for your advice, help and suggestions. it really is god to know that if one has a problem there is a genuine web site that one can enter to find advice , help and suggestions. It is also very interesting to read of the problems others have and the advice given. As a matter of interest, if I had taken note of either of the 2 contractors I approached for help to my problem, I would either have excavated the car parking space, or had an RSJ placed.

 

[MdB]

if I had taken note of either of the 2 contractors I approached for help to my problem, I would either have excavated the car parking space, or had an RSJ placed.

Either of these two solutions may still be required. If the reason for the bulge is a failure of the main structure of the ceiling then this needs to be identified and sorted quickly or you will have a car in your basement shortly. If on the other hand, it is just the laths that have come adrift then solving it is easy. Until you do the investigation, you won't know. Nobody here has seen the problem, whilst your contractors have.

 

[Schoolmarm]

Does there look to be any sinking in the car parking area?

 

[chuckey]

have you tried standing on a stool and (gently)pushing the ceiling back up? If you can its just a lath and plaster problem, if you can't its a mega problem.
Frank

 

[Flyfisher]

Does there look to be any sinking in the car parking area?

Good question.
There does seem to be a potential structural issue here; you've a sagging ceiling with a car parked above it - the car could be a coincidence or it could be the cause. I tend to agree with MdB - further investigation sounds necessary to find out what's really going on.

 

[Hatster]

Does it actually matter what the problem is? Surely this is what your buildings insurance is for?

Meanwhile, I agree that you should prod the ceiling gently and see how easy it is to push back into place.

 

[Penners]

Does it actually matter what the problem is? Surely this is what your buildings insurance is for?

Sorry, but no. Buildings insurance is very unlikely to cover against a "wear and tear" issue. And any of the likely causes of this bulge will almost certainly come under that heading.

"Impact by cattle" seems to be a favourite phrase among insurers, and this is normally covered. So if anyone dropped a cow on the car park..... :wink:

But I do agree with others above. Try Frank's suggestion of seeing whether the ceiling bulge will respond to muscle-power. If it will, then it's probably a lath-plaster issue. If you can't lift it, then you need to start taking it seriously, without delay.

Your builder's RSJ suggestion may not be a million miles off-target.

 

[Hatster]

Buildings insurance is very unlikely to against a "wear and tear" issue

Ah - that explains why it's a problem!

 

[porter]

Penners was correct, the building insurance company did not want to know. Berore I asked for suggestions on this web page I did contact my insurers, they sent a surveyor, who took one look at the ceiling and basically informed me it was my problem not theirs. And he did not have any suggestions either

 

[Schoolmarm]

..........but please can you tell us, is there a sunken area where the car is parked?


And, what were the contractors going to do?
What did they say the problem was?


Is the car parking area one of those strange things in london not belonging to your house even though your cellar is below it?

AAAARGH!! tell us some stuff!!!

 

[Penners]

Is the car parking area one of those strange things in london not belonging to your house even though your cellar is below it?

If it is as Schoolmarm suggests, then my advice would be simply to do nothing - just wait.

You could win yourself a car. :wink:

Mind you, getting it out of your cellar would be your problem.

 

[Schoolmarm]

:lol: :lol: :lol:

 

[Flyfisher]

I wouldn't dismiss the insurance angle so lightly. I agree that a sagging ceiling because of nail rot etc is 'wear and tear' (heck, if insurance companies paid out for that sort of thing I'd be sitting on a Carribean beach while our house was completely repaired with insurance cash!), but surely structural problems arising from ground movement would be covered? Having said that, simply asking an insurer if something is covered is likely to produce an automatic 'no' response, whatever the claim, so be prepared to argue your case (possibly a tad too cynical).

But I share 'marm's frustration - we're all just speculating until some firm information about the extent of the problem is revealed.

 

[Penners]

possibly a tad too cynical

Oh no - not where insurance companies are concerned!