Ceiling crack advice please

[robert]

We have a ceiling with a smooth emulsion finish, unfortunately long cracks appear in the course of every few years - one along the line of a plasterboard joint and two others that are not in line with the plasterboards.

I have repaired them with a d-i-y filler (made up polyfilla or similar) in the past but have decided to do something that will hopefully be a bit more permanent this time.

I have raked the cracks out - the depth appears to be around 10mm and was wondering about applying a gap filling adhesive (No more nails?) in the apex of the crack and finishing it off with either a light weight sandable filler which I imagine will give the finish most likely to blend in once painted or possibly caulk which I understand has the benefit of being slightly flexible but may not blend in as well as the sandable filler.

I would be grateful for any suggestions or comments.

[The Medway Handyman]

Caulk is flexible enough to withstand the movement without cracking - but very difficult to sand, so you have to get it smooth when applying.

[Mary Fisher]

Our 1930s semi has settled over the decades and cracks appeared across the corners of rooms. A couple of years ago I was fed up of seeing the ones in the sitting room when I was lying on the sofa so, despite protestations from Spouse that it wouldn't work, I got out the steps and filled them with either acrylic or silicone filler from a gun.

Sorry, I can't remember which it was.

I smoothed the filler with my wet finger then painted the ceiling.

If I look intently at the ceiling I can see where the cracks were but it really isn't important, the paint isn't interrupted by black lines of the cracks.

I was very pleased with the result. Amazingly, so were several of our pernickety 'children' who have been complaining about the state of that ceiling for very many years. I was surprised that they even noticed!

Oh - I didn't rake out anything, simply filled and smoothed.

Mary

[NOSPAMnet]

I'd agree about the sanding attributes of Decorators caulk . But how about filling to some degree with some sort of filler then using plasterboard jointing cement ( Gyproc is one make) to complete and that gives a very smooth finish

[Dave Liquorice]

Trouble is jointing stuff sets hard and the movement will crack it. You want something like decorators caulk that stays flexible to take up movement without cracking. As Dave says it's next to impossible to sand caulk but it is easy to get a smooth finish with a wetted spatula. I wouldn't use a finger on a crack as fingers are too soft and will make a slight U along the line of the crack.

[PeterMcC]

I've been very pleased with the results in similar situations using Gyproc Easy-fill.

[Dave Plowman (News)]

I've found a good flexible caulk works well - but since it shrinks and can't be sanded you'll need three or four goes to get the crack level. Which takes rather more time than other fillers. But seems to be worth the effort.

[robert]

In message , robert writes

Very many thanks for the suggestions. It looks as though the consensus is to use caulk although it is likely to be more difficult to achieve a finish that completely blends in with the existing surface.

In my first post I indicated that I was thinking of using an adhesive with gap filling properties in the deeper part of the crack - my thought was that this could help stabilise things. I wonder if anyone has any views on this?

[NOSPAMnet]

I'm sure there is a joke in there somewhere ..lol

[Dave Plowman (News)]

It's not difficult - just takes longer. And since caulk dries quicker than pollyfilla etc perhaps not that much longer.

[mail]

=A0 London SW

How about scrim? ie rake out crack - sand down 1" either side 0.5 mm - scrim and finish? I would use SBR in the mix If you want belt and braces use the caulk under to a depth of 1mm and finish on top of that Chris G

[Mr Fuxit]

FFS! This is a ceiling, not a Space Shuttle!