Any idea if the cracking in our lathe plaster ceiling due to water leak?

[stressed2007]

The ceilng in the dining room (quite a large room) of our house which is lath and plaster has in the last few months begun to crack very badly. Our decorator said he thinks the whole ceiling has "gone" and will need replacing (he has no vested interested as he cannot do this). There are very large cracks on several parts of the ceiling and it looks like chunks may come off if it is not attended to. When we bought the house nearly 18 months ago the surveyer noted several hairline cracks and said we should budget in replacing the ceilings for some time in future as such plaster does not last forever but impression was that this was not imminent but some time in the future.

We had a leak in the bathroom over our kitchen which badly damaged that ceiling (plasterboard to be replaced etc). We are trying to ascertain if water damage may have caused problem with dining room ceiling. The leak was not over the dining room ceiling but the water may have run along the joists in that direction too and caused damage. There is also no brown water marks on this ceiling (where there is on the kitchen ceiling) but I understand that the lathe plaster may act differently to plasterboard. If the problem has been caused by water damage then it is covered by insurance if not it is our cost to replace. Do you think the significant cracking which occurred after our leak could be due to the water or is this just coincidence? If not any ideas how a ceiling with a few hairline cracks can suddenly (over a few months) get into this state - the rooms above were used by previous owners so I don't see how we can have casued this just be using the same rooms but maybe we have.

Any ideas welcome.

Many thanks

[CMOTdibbler]

DH who deals in insurance property claims says that it is totally normal for lath and plaster cracks to progress like this - once they lose their key (as evinced by the hairline cracking), they move fast. The whole ceiling could go en mass.

No chance on claiming it as water damage

[stressed2007]

that's disappointing - do you know if it WAS water damage if you would see brown marks or not (it was a buiding company that told us you would n't see it and that this might be the reason). Looks like we may be having words with our surveyer! Thanks for the info.

[CMOTdibbler]

Dh says that you see water damage as marking and it coming down on your head pretty rapidly if already cracked.

If your surveyor told you it would need replacing, then I don't think you could have any arguement with him. These are unpredictable things - our well dodgy ceilings in previous house held on for 3 years past the point we thought we'd have to replace them

[stressed2007]

It was said in context of long term budget -in same way as some windows might eventually need replacing, flooring upgraded etc. Long term - such as 10-15 years not within 18 months you see.