Why have lines appeared in my plasterboard ceiling?

Question

I live in a house built 18 months ago. It has a plasterboard ceiling.

Over last few months, lines have appeared in the ceiling at the place where the individual plasterboards meet. If you run your hand over them you can tell they've sunk slightly under their own weight. I don't mean my ceiling is about to collapse, it's more of a cosmetic thing really.

What has caused this and how can I cover it up, if at all?

Answer 1

When you say that the plaster board has sunk, could it also be that the compound between the boards has shrunk, and created the illusion that the board had dropped? This is an important distinction. If the plaster board is in fact dropping, you have a fastener problem, and this needs to be addressed immediately
by screwing the board tightly to the lathe or joists that it is attached to.

If, however, the compound between the joints has lost some mass due to dehydration, this is cosmetic; but reveals a potential costly problem. Some of your other answers refer to taping of the joints, and it is possible the contractor simply applied compound between the joints without tape. This is a big no-no and a legitimate cause of action to have the ceiling refinished properly by the original contractor.

Answer 2

sounds like the drying out of the ceiling joists, (the timber the plasterboard is nailed onto) as they contract with drying they will cause movement, enough to show the where the joinings of the plasterboard are. to solve this, get a plasterer to skim coat the ceiling with plaster finish. messy job make sure he has dust covers on everything including the floor. if he/she does then can be kept to a minimum disturbance.
you will of course then have the trouble of painting the ceiling.

Answer 3

If it is cosmetic (the cracks aren't too big) don't worry too much. You may find it is because of the hot and dry weather we have been having and they will close up again.

If they don't go of their own accord and are hairline you can get paint in the DIY sheds that are designed to cope with just that problem. Follow the advice on the tin as to the size of crack the product will cover. If the cracks are wider than the paint will cope with then you can use a filler (again as directed but it is a messy job and a pain in the neck, shoulders etc.) or get a man in (as previously suggested).

Answer 4

If house was only built 18 months ago, then (in UK) its covered by the NHBRC gaurantees.. The plasterboard has cracked because the joints were not taped, which prevents cracking like you have.

Answer 5

Altamenty Your ceiling wasent installed right. It sounds to me that the contracter that installed the plaster boarded fitted the joints to tight and didnt tape the joints. Or he may have used the wroong type of mud. He or she may not have put enogh screws in the plaster board to hold it up (about every 6-8 inches). Another thing is that they may not have used the right thickness of board if its to thin the board with sag in between joints over time half inch or thicker should have been used

Answer 6

i think it would probably be that
either when the plasterboard ceiling was fitted it wasnt taped along the joints , which gives it a little movement to stop cracking , which if it was the ceiling would be best re-taped and plastered or the joints werent staggered

Answer 7

Because you house is settling and it has shifted some since you have built it.
Your contractor may still be responsible to fix it.

Answer 8

you need to ames the joints they have shrunk dew to drying or they wasn't coated enough in the first place and as your paint work as aged they have become visible