Should plasterboard join lines be visible?

[Bakersdelight]

Hello
We are in the process of gutting our mid Victorian semi detached house. We had the original ceiling taken down in the master bedroom and new plasterboard ceiling put up and skimmed. We also had the very long internal hall on the party wall plaster boarded and skimmed to improve the transfer of sound between us and next door.
I can now see the lines of the joins between each board. The surface is flat but I can see the lines of all the plasterboard. My bedroom ceiling looks like a patchwork quilt and my 7m long hall has lines at regular intervals all the way along it. Can anyone explain what has been done incorrectly for this to happen and what would need to be done to rectify it?

The plasterer has only done one layer of skim and there should be 2. He was rushing the job. Id complain and demand a reskim.

Can you see the lines through the plaster, like a crack - or is that in certain lights you can tell where the line is?
I ask because if if is like a crack, it needs to be reskimmed. If it's like a bump/shadow, you may find it's because the plaster boards are attached to joints that are not all completely level, due to age. We have had an extension attached on the back of our existing house and the new ceiling boards attached to previous joists are not as smooth as the new part - although cannot be seen unless at night where you can see slight shadows. (difficult to explain!)
Have you spoken to the company that did it and ask what their reasons are?

Thank you both for your replies. The lines aren't cracks they're just darker lines in the hallway and in the bedroom the ceiling looks like a patchwork, where its not just lines but whole sections of light and dark hence the patchwork look..
I took some photos of the ceiling the other night but it's hard to photograph. (attached)

It needs skimming again.

When they've skimmed over plasterboard they should have done a min of 2 coats.

1st coat is usually 2-3mm thick and second coat around 1mm thick to cover any defects or lines.

Hi I'm a professional plasterer reading some of these comments I have to say unless you are 100%sure maybe dont comment.so the lines your seeing are from where the plaster is drying differently on the joint it maybe heavier here if it hasn't been bonded out (which would cost extra) apply a mist coat to the areas once completely dry you will be able to tell then if the areas are ok which I'm sure they will be

Check the area feels smooth and flat once painted you will be able to see the finish your decorator will be able to do any spot filling you may need

You say it is flat, can you feel the line or just see it? If you can only see it then You probably need to paint it and it will then be fine - but you must wait a good while to dry out first.

I'm with Dan, I reckon it'll look fine once it's been painted properly.

Take notice of what Dan said but make sure it's all dried out before you paint otherwise you will get damp walls with a white fungus on

Hello, thank you for your input. It's good to have comments from professional spreaders! Its all already been mist coated and painted with three coats of emulsion.

Tapered boards been used, the joints maybe bond coated to get a flush surface between the boarding. These take longer to dry due to thickness comparison to the skim coats. You then have painted them too soon and not aloud to dry right back. Just because Nick Knowles and his DIY SOS crew paint right after final pull !! You should wait till it had dried back and the same colour through. Right or wrong ! Did you paint this before it was allowed to dry.

DH a builder, we'll actually a joiner by trade but has worked alongside many plasterers over the years and can do a mean job of plastering a wall himself if it's in our house or families (obv. leaves it to the pros on an official job)
He says from what he has seen that the joins often show till completely dry as they dry out differently and any plasterers he knows always advice let it dry ptoperly before going near it with paint etc. despite there being products now that allegedly can go on straightaway.

It was painted about 4 weeks ago. How long does the plaster need to fully dry out?

We've just had a new ceiling put up and were advised to wait four weeks for it to completely dry out before doing the mist coat. Not sure if that is excessive but I was fine to wait.

Sounds like they haven't taped and filled across the joints. This is my party piece. We had some work done in the house and I refused to pay extortionate rates for a plasterer do disguise the joins in the wall so learned to do it myself. You basically put tape across the joins to disguise it then put a thin layer or filler over the top. Leave it to dry, sand, repeat until joint gone.

www.wonkeedonkeetools.co.uk/plasterboard-joint-tape/what-is-taping-and-jointing/

Sounds like they've been cutting corners.

Thank you, sounds like they’ve rushed the job .
Managed to get this photo of the ceiling today.
What should I be asking them to do to fix it?

No, there needs to be more plaster

After looking at it painted that's terrible

Should I ask for it to be reskinmed?

Yes you need a reskim.looks to me they never used tapped edge boards just the square edge board