Visible Joints In Plastered Ceiling

mrsparks · Post by **mrsparks** » Fri Dec 02, 2022 6:04 pm

I've had a ceiling plasterboarded and skimmed recently. It looked pretty good. I've painted it - one mist coast and then two coats of Tikkurila Ant Reflex White 2. I was still very happy. Then one sunny day I saw for the first time that the joints - presumably the joints in the underlying plasterboard - were really prominent. Some days you wouldn't even notice but when it's particularly bright they're obvious.

Question is, what should I have done? Should I have sanded the ceiling first - but then I didn't really know where the joints were. Should I have used a bright artificial light to look for imperfections after painting (maybe after the mist coat)?

And what now? Should I try and do something about it and if so, what?

aeromech3 · Post by **aeromech3** » Sat Dec 03, 2022 2:47 pm

I had a ceiling installed, plaster board and the joints were taped and skimmed locally, the result is much the same as you describe. However you indicate as if whole ceiling was skimmed in which case the joints should not ever be visible; artrex used to be the way out, maybe you will get more responses.

Deleted-user-3 · Post by **Deleted-user-3** » Fri Dec 09, 2022 6:34 pm

so normally you cant see them but when the sun shines at just the right angle on a wednesday about 4 o clock theyre obvious?
i hope its not mr sparks because id cut your first fix cables right back but if its MRS PARKS then ignore that last comment. We need to see pics really before commenting on standard of workmanship, cracks are a bit of a no-no after a reboard and skim but describing "imperfection" is a tricky job..
Im kind of expecting whats happened is theyve used tapered edge boards designed for tape and joint method of finish instead of square edge boards designed for skimming the whole thing and what has occured is that where the plaster is on thicker (over the tapers) then it has shrunk more than where its on thinner (all plaster shrinks as it dries the water has to go somewhere). Thick plaster shrinks more than thin plaster, so what you may have are very shallow indentations where the tapered edges of the board are.

How much of a problem this is depends on the circumstances..
Im also guessing that by your choice of high quality matt finish paint and youre otherwise chufftness with the job that the lads did a pretty good job
So if its a "4 oclock at this time of year with the sun on the horizon looks awful but rest of time you dont notice it especially when you look straight up".. then its fine, natural product etc, you can expect the lads to be magicians, have a look at the plasterwork above every wall uplighter you see, they show up every imperfection

If however, you look straight up in most lights and you can see every joint or even a few then yes, really, they should come and have a look and maybe easy fill the joints out or give it another go over

mrsparks · Post by **mrsparks** » Fri Dec 09, 2022 7:01 pm

cwplastering wrote: ↑Fri Dec 09, 2022 6:34 pm so normally you cant see them but when the sun shines at just the right angle on a wednesday about 4 o clock theyre obvious?
i hope its not mr sparks because id cut your first fix cables right back but if its MRS PARKS then ignore that last comment. We need to see pics really before commenting on standard of workmanship, cracks are a bit of a no-no after a reboard and skim but describing "imperfection" is a tricky job..
Im kind of expecting whats happened is theyve used tapered edge boards designed for tape and joint method of finish instead of square edge boards designed for skimming the whole thing and what has occured is that where the plaster is on thicker (over the tapers) then it has shrunk more than where its on thinner (all plaster shrinks as it dries the water has to go somewhere). Thick plaster shrinks more than thin plaster, so what you may have are very shallow indentations where the tapered edges of the board are.

How much of a problem this is depends on the circumstances..
Im also guessing that by your choice of high quality matt finish paint and youre otherwise chufftness with the job that the lads did a pretty good job
So if its a "4 oclock at this time of year with the sun on the horizon looks awful but rest of time you dont notice it especially when you look straight up".. then its fine, natural product etc, you can expect the lads to be magicians, have a look at the plasterwork above every wall uplighter you see, they show up every imperfection

If however, you look straight up in most lights and you can see every joint or even a few then yes, really, they should come and have a look and maybe easy fill the joints out or give it another go over

Mr Sparks or Mrs Parks - that is the question!

The imperfections in the ceiling are visible any time it's bright - not just when the sun's in the right direction. It's pretty much on every joint in the underlying plasterboard. And when I say imperfection, I mean it's a little proud - in other words either the plaster is thicker there, or it's sagged before drying. When I put a straight edge, like a metal ruler, across the joint it rocks. If I pull the ruler along the joint at right angles it shaves the plaster (the painted plaster) away. The ceiling was definitely boarded with square edge plasterboard. The joints had scrim tape applied - I'd say the boards weren't butted very tight at the joints. The joints weren't pre-filled as far as I know - don't know if that's normal. There are no cracks. As far as I know - I was away at the time - it was given one coat of plaster. I'll try and take a photo tomorrow but's it's really hard to get the camera to focus.

Deleted-user-3 · Post by **Deleted-user-3** » Fri Dec 09, 2022 7:27 pm

sounds like a rough job, very rough. board joints should have been tight, shouldnt require filling before hand and should have had 2 coats. wouldnt bother ringing them back, if they cant do it right first time...
The scrim probably did sag as you say and they probably could have caught and sorted it if theyd left it a bit then given it another coat..
One coat over rough boarding for a domestic customer is asking for trouble..
As for a solution..
Well i suppose you could find the scrim ends, pull it straight off all the way leaving a hollow and a board joint, fill the joints a bit with easy fill so the scrim doesnt sag and let it dry, re scrim it and fill it back up slightly proud and sand it back level.. pain but diy doable
or just get it reskimmed by a competent tradesman?
sorry for your loss..

mrsparks · Post by **mrsparks** » Fri Dec 09, 2022 7:41 pm

cwplastering wrote: ↑Fri Dec 09, 2022 7:27 pm sounds like a rough job, very rough. board joints should have been tight, shouldnt require filling before hand and should have had 2 coats. wouldnt bother ringing them back, if they cant do it right first time...
The scrim probably did sag as you say and they probably could have caught and sorted it if theyd left it a bit then given it another coat..
One coat over rough boarding for a domestic customer is asking for trouble..
As for a solution..
Well i suppose you could find the scrim ends, pull it straight off all the way leaving a hollow and a board joint, fill the joints a bit with easy fill so the scrim doesnt sag and let it dry, re scrim it and fill it back up slightly proud and sand it back level.. pain but diy doable
or just get it reskimmed by a competent tradesman?
sorry for your loss..

Thanks for your replies. Anything I do now is going to be painful - maybe I'll revisit in the new year.