Had a builder round today to give an estimate for work in the kitchen. Anyway, he took a look round, and noticed cracks in the ceilings in a couple of rooms. These seem to be joins between plaster boards. I was going to fill with plaster then paint. He said the cracks would soon come back, especially if someone walked around in the roof space (t'is a bungalow). He also said you'd see them even with lining paper. His suggestion was that they could screw onto the ceiling new plasterboard joined together with fiberglass tape, and then skimmed/plastered over. That way you won't get cracks appearing.

So, is what I am being told correct? I could believe the bit about cracks appearing soon if painted, but I am not convinced about them showing through lining paper.

Cost is about £300 per room, that is probably before VAT. Two bedrooms need doing and maybe the lounge.

Yes it is. The price isn't too bad considering the amount of work needed to achieve a flawless finish. We had the same thing done to 4 rooms in our house. Absolutely worth doing in my opinion otherwise you may regret it for the sake of a couple of hundred pounds!

for 300 quid per lid i'd want a guarantee....
if the cracks come back, so does the bloke who said they wouldnt...

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Thanks for both replies, very useful. I had a word with them and there is no guarantee which is not that surprising as I could invite my pet baby elephant up into the loft for tap dancing lessons, and that would crack anything. But they are an established firm, and two colleagues gave them glowing reviews, so they are not cowboys.

it is very hard to give a guarantee that it will not crack as there are many different variables that can cause plaster to crack but new boards skrim on joints and a skim is your best option, mabey even double skrim just to be safe

Thanks.

If they do reboard, make sure that the old and new joints are staggered as much as is possible as this will help prevent cracks opening. For extra certainty, you could supply them with 96mm fibreglass tape instead of the usual 50mm.

well played joe diddnt think of the wider skrim

I wouldn't overboard and skim all the ceilings. The weight alone would ring bells. I would knife the cracks, skrim up with cotton then over skim the boards.

Interestingy enough that is exactly what the second builder said when I showed him the ceiling. And this chap showed me some simple ways to repair other ceilings without having to pay a large wodge for skrimming etc. I tend to trust this builder more as he does not go out to find work for him to do, and he has made useful suggestions to help me improve the work I am doing myself.

The weight of a skimmed ceiling 3m by 3m is about 100kg of dead load evenly spread over approx 8 joists. at 12kg per joist, thats less than the joist weighs. Considering that such a room might have a dozen people in it weighing approx 1000kg, the weight of the boards is irrelevant.

When acoustic ceilings are hung, they weigh about five times as much as normal ones, yet the building inspectors never mention the additional load. If it was a problem, I am sure they would

its fairly common practice to over board ceilins now mate, its easier and cleaner than ripping it down

Yes it's common practise these days.

I took a quick look this evening, and the ceiling does not obviously flex when pushed, though clearly it will when someone walks in the loft. Searching online I saw someone say that it is possible to clean out the cracks, then apply decorators caulk using a tool to level it flush with the plasterboard, although two applications might be needed as it shrinks. And I suppose some Gyproc either side if the surface layers are missing. I am tempted to try this given that builders caulk is flexible and will take paint/paper, and to my naive ignorant mind it sounds plausible. My own test coverings of gyproc look perfect, but given that gyproc is inflexible, it will not last.

How bad are these cracks?

I wouldn't go down the cualk route, If I was going to use a flexible filler I would use Toupret Elafib.

But the cracks would have to be pretty bad for me to do anything other than to use additional fixings either side of the crack, rake out, skrim tape then joint with Gyproc easifill.

The overboarding seems overkill unless there is another reason for the builder suggesting this

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