Whats the best way to repair this crack?

[Hodo]

I have tried joint tape and skim but it cracks again.

It looks as though the crack is in the brickwork rather than the plaster.

 

[alan333]

A plasterer once told me that to repair such a crack successfully you need to remove the plaster around the crack, point the crack in the brickwork properly, then repair the plaster.

 

[vinn]

Most cracks less than 5mm are considered almost irrelevant - they are often caused by shrinkage or thermal movement.
There's lots of info on here about similar cracks.
When did you very first notice the crack or disturbed decoration?
Is the wall solid or double skinned - is it rendered?
Is that a bedroom?

 

[roy c]

You have got to open the cracked area up by knocking the plaster and render off about 9 to 12 inches all around it, then cut some mesh to fit in the space(you could double the mesh up if you want) and nail it with board nails into the wall (mortar joints) to hold mesh then scratch coat it and float it out and skim it level with surrounding surface...

 

[roughcaster]

It looks as though that crack is coming from the lintel, quite a common type of crack really.
I'd do exacly what Roy says. Also, once you have it cut back and the wire lath/mesh is fixed in place, give the whole area a damp down/spray before you scratch coat. You could even brush on some pva around the edge before you scratch. If you do use pva, make sure you scrach onto it while it's still wet/tacky.

 

[wonderwire]

.

 

[Hodo]

@roy c, @roughcaster - thanks. i am new to this, forgive the simple questions!:
- when you say remove the plaster and render, you mean basically everything to expose the brickwork?
- by mesh I assume you mean metal mesh lath like this? http://www.wickes.co.uk/Wickes-Galvanised-Metal-Mesh-Lath-2500x700mm/p/104089
- for the scratch, i assume i'd use something like thistle bonding coat, and then multi-finish for the float and skim?

Thanks again!

 

[roy c]

No! you scratch it out with 5-1 sand (sharp) and cement with a drop of water proofer in it ,after you have done what R/caster said about the PVA. The next day or longer you then mix up your float coat 6-1-1 (Sharp sand cement and lime ) Lime is optional on a small area like yours. Just damp the scratch a bit with water and put on the float coat fill it right out and leave it for a while to pick up then screed it across the area you have laid on and go and make yourself a cup of tea or coffee what ever your preference. When you come back float it out with a float with small nails pokin' thru it and that will "devil" it up for the key to the skim coat. If possible try to keep the float coat about 3-4mm below the surrounding surface and maybe scrape off around the edges so the new will blend in with the old.Then when you skim it with (multifinish) put some pva around the edge of new and old work and put a coat of finish on and let that firm up a bit then put your next coat on and and give it a bit of a flattening and clean up around the edges with a sponge. after a while wet your trowel blade and skim it to a flat even surface, then sponge the joint up again.I cant give you precise times to trowel up as it can be different on different backgrounds but dont over trowel it and you should be fine. If you cant understand the procedures then you will have to get someone to do it for you..Good Luck!