Fixing Ceiling Hairline Cracks once and for all?

paperclap

Hi all,

After doing some light filling around spotlights (where the plasterer hadn’t done his job properly!), I’ve spot painted. And you guessed it, you can see the new paint a mile off. Quite shocked, as the ceilings were only painted ~18 months ago.

Anywho. The ceilings used to be artex. Where the joins meet, some hairline cracks were already present. Plasterer (despite not doing the holes properly!), seemed to have done most things right. PVA’d, taped (with mesh tape), two coated. 

But, the cracks have reappeared. Now, how can I fix these once and for all?

Don't want to have to have them reappear again after repainting! 

Thanks!

stuart45

I've had the best results with paper tape and Knauf fill and finish. Mesh tape is quicker and easier to use, but does flex more than paper and more likely to crack. You need to bed in the tape, then 3 coats over the top.

grumbler

I used once (or something similar).

However, it shrinks and for bigger cracks requires several fillings. Also, it's more difficult to sand and has to be applied neatly to avoid sanding.

paperclap

Done a few mins of research now… and hadn’t realised just how terrible mesh tape is compared to paper tape!

What makes Knauf Fill and Finish superior to regular EasiFill?

stuart45

It's what I've found works best for me.personally, but some people might prefer easyfill. 
The disadvantage of ready mixed fill and finish is that it takes 24 hours between coats, so if I had to do a job and finish it the same day, I'd use a faster setting filler.
However, if you have the time, it's really easy to use, and sands or sponges to a perfect finish.

paperclap

Thanks!

I think I’ll stick with EasiFill, only because I have some, and have used it in the past.

So, I can grab some paper tape. Filler in, paper tape on, bed it in further. Then wait to dry, and apply a top coat of filler? How much either side?

FreeBear

paperclap said: Anywho. The ceilings used to be artex. Where the joins meet, some hairline cracks were already present. Plasterer (despite not doing the holes properly!), seemed to have done most things right. PVA’d, taped (with mesh tape), two coated. 

But, the cracks have reappeared. Now, how can I fix these once and for all?

Are the ceilings lath & lime plaster ?

Cracks will continually appear as the laths move, and if the nails are starting to rust, the problem will only get worse.

Plasterboard ceiling with long straight cracks ?

Unless the ceiling was put up fairly recently, the boards have probably been fixed using nails. Over time, nails "pop" which allows for a small amount of movement between adjacent boards. Putting in some screws can help, but it is a crap shoot as to whether you hit the joists or not..

Short of taking the whole ceiling down and starting again, filling the cracks as they appear will be your best option. Or you can cover the ceiling with lining paper (woodchip or Anaglypta works too) and then paint.

stuart45

paperclap said:

Thanks!

I think I’ll stick with EasiFill, only because I have some, and have used it in the past.

So, I can grab some paper tape. Filler in, paper tape on, bed it in further. Then wait to dry, and apply a top coat of filler? How much either side?

Use a slightly wetter mix to bed the tape. You might find wetting the tape first helps stop air bubbles. Let the tape go solid before going over with the first coat. 
I normally use a 4 inch knife for the first coat, 6 inch for the second and 10 inch for the top. Last coat a bit wetter.
When bedding the tape, start from the centre.

paperclap

Thanks both

It’s a regular plasterboard ceiling, fixed with nails. Haven’t seen any nails pop (apart from in an airing cupboard, which hasn’t been skimmed!).

In the living room, the joists are actually ever so slightly bowed I think and caused the ceiling to bow. Plasterboard screws didn’t help tighten it up.

Thanks for the skimming notes. Hadn’t realised it’d need three coats! Only got me a 4 inch knife. Guess I’ll have to get myself a 6 inch and a 10 inch.

When doing the wall cracks and wall/ceiling junction cracks, is it best practice to also paper tape and give three coats? All the same principle? Walls are brick and mortar

stuart45

Wall cracks do the same. Wall/ceiling 2 coats. Bed the tape at junction and leave. Then do either ceiling or wall side first coat and leave. Then do first coat on wall or ceiling. Repeat for second coat. The 4 and 6 inch knives are enough for the junctions. 
Might be worth investing in a cheap plastic drywall mud box as well.

paperclap

Thanks so much!

Just realised I’ve got a lovely (unused) Ragni 11” trowel… so that should be perfect for the final coat of the ceiling cracks.

Pray for me. I’m not the best!