How to stop hairline cracks in sheetrock join coming back

[tew1]

Hi,
I have a room where there is a hairline crack which runs around the entire ceiling about a foot from the wall. This corresponds with joins in the sheet rock. It is 50's construction, it has been plaster skimmed all over but there is no hessian tape over the joins apart from wall corners. There's no texture, it's smooth. I've tried cutting out the join and filling with polyfilla, then sanding in the past, but all the cracks have come back.
I'm thinking of cutting out the cracked skim plaster to about a 1/2 inch, fill with a builder's grab adhesive and smooth it off (like grip fill), then tape, mud and sand smooth as you would drywall. Will that work, and stop them coming back?

Untitled

• tew1
• 22 Nov 2013
• 1

 

[roughcaster]

Forget the grab adhesive. First of all, check that the plasterboard is well fixed, put extra screws in where you can if there's any movement in the sheets of board. Get a scraper or similar, and remove all the loose material, old filler/flaking paint etc along the crack. Give it a good clean. Once it's cleaned, mix up a drop of filler, run a wet brush/pva along the crack, then fill up the crack, flush it off, then leave the filler to set. Once it has set, you can now put on your tape with the "mud". Once the tape is on with the mud, leave it to dry out, then go over it again with the mud, feathering away the edges. Let that dry then sand it down with a 120 grit sandpaper.

 

[joe-90]

The only thing I've ever found that works is the new polymer lightweight fillers like Red Devil/ Wickes. They feel like an empty bucket when you pick it up - but it really does work well. Unlike that rubbish easifill it dries to a white cork like texture that expands and contracts and doesn't crack.

 

[roughcaster]

I did say that i would give Red Devil filler a try Joe, haven't got round to yet though but i will.

 

[joe-90]

The Wickes one is good too. Really good for shallow and hairline problems.

 

[roy c]

Is it anything like "One Strike"Joe? That is the only light weight filler l have used.You keep banging on about this" red devil" so it must be good...

 

[tew1]

Thanks. Is it the kind of lightweight filler like the deep gap filler (the grey polyfilla, its almost like mouse)? So, make the crack bigger, pva, fill with lightweight filler, allow to set, then tape and mud as you usually would ontop of that. The sheet rock is nailed to the ceiling joists, so i'll run a line of drywall screws along either side of the crack first I think. Has this worked for you, the cracks don't come back do they?

 

[roughcaster]

Now we have confusion. The prep method i'm refering to, is for using a powdered filler. I don't know whether you need to wet/pva the cracked board if you're going to use the lightweight filler Joe refered too. Everything else would be the same, mud/tape/mud/sand.

 

[roy c]

I would strip back any paper around the crack cut into the plasterboard about an inch either side of the crack to a depth of about 4 mm then neat unibond on it and around it put a thin skim of multi over it bed some fibre tape in it then skim it with multi to a flat finish. All these so called fillas are alright but that's the only way I would gaurantee a crack not reopening to a customer.

 

[Alastairreid]

Its fine rubbishing the old tried and trusted methods for repairing such cracks!! at least we know they work!

How do you know these new products wont fail after a couple of years?