Hair line crack on old plasterboard

[bignick]

Thoughts needed!
Just plastered a 36mtr plasterboard wall(studwork). Boarded 8 months ago so scrimmed joints, sealed with plasprime, let it dry, plastered next day.
Went on lovely, no problems, a week later every joint had the finest hairline crack, why?
Customer not bothered as fitted bookcase is covering the full wall, just annoying as not everyone is layed back as this customer.
Thoughts please

 

[Monkey Boy]

Board edges had that extra suction created slight shrinkage crack?!

 

[Ktownsend]

Plaster shrinks and cracks. Stud walls move. Nothing more to it

 

[BryanJ]

From past experience, I would go for paper tape on stud work.
I am not saying it will not move, but cracks will be behind paper and not show on face of plaster.
Seen plenty of old timber stud and ceiling cracks on joints, but not so many on old Artex ceilings that had paper tape.
It does take more time to bed the paper tape and slightly more thickness on finishing coat.
But agree, if there is excessive movement or shrinkage you are going to have cracks.

 

[Deleted member 32554]

Heating switch on

 

[bignick]

all comments noted, underfloor heating in polished concrete was on, 3mt high glass panels at end with sun streaming in not good. Never think of paper tape, would seem like going back to the eighties bedding bandage scrim on joints first.
Did a month in Brixton about 1986 and all they used was hessian scrim, setting was
1/4 inch thick to cover it!

 

[Squarehead]

all comments noted, underfloor heating in polished concrete was on, 3mt high glass panels at end with sun streaming in not good. Never think of paper tape, would seem like going back to the eighties bedding bandage scrim on joints first.
Did a month in Brixton about 1986 and all they used was hessian scrim, setting was
1/4 inch thick to cover it!

It's only after advice on here that I knew about the strength of paper tape. I always thought it was tape and joint only. If I think something's prone to cracking I paper tape first and cut render mesh on top of that. Vastly improved on call backs. Some will laugh at this, saying things like "fook it, just scrim it, customers problem..... Blah... Blah.. Blah... Blah"