Staggering Plasterboards

[andyd]

I am replacing a ceiling having up-graded the insulation of a flat roof and have been told that I should stagger the plasterboard joints. What I don't know however is should it be the joints which run across the joists which are staggered or should it be the joints which run along the joists ? Would much appreciate advice.

 

[masona]

Is the flat roof ventilated?

 

[andyd]

Yes it's well ventilated. It's a kitchen extension which was pretty cold and the old ceiling had cracked along the joints. I also needed to get behind the ceiling to run a load if cables, so down it came. Now insulated with Celotex. My plasterer told me to stagger the joints when boarding out but didn't say in which direction. I can't get in touch with him and want to start boarding out. I expect its the joints crossing the joists which should be staggered but just wanted to check.

 

[masona]

I would say staggering is not important and I always keep the joints in a straight line making it easier to tape the joints. I also use nogging on the edge of the plasterboards as well to prevent the bowing.

 

[andyd]

Thanks, it did cross my mind that staggering would make scrimming a pain. I've never staggered one before and not had one crack yet so perhaps I won't bother.

 

[-dj-]

just because they havn't cracked in the past doesn't mean they never will, the staggering of boards will reduce the likeliness of cracking. being a kitchen you should be using foilbacked board, also if you havn't got nogs to cover every edge of the board then you must use 12.5mm board, personally i would always use 12.5 anyway. the way to stagger boards is displayed in this link near to the bottom of the page.

http://www.british-gypsum.com/PDF/c60_103.pdf

dj.

 

[jbonding]

as dj said always stagger the boards it just doesnt reduce cracking it will also strengthen the ceiling, if there is any movement in the structure the crack will find the easiest place to appear, i agree if its an older property movement is slight but in todays current climate who knows what the future holds.

 

[andyd]

Thanks for the advice. I'm fitting foil backed and will stagger as recommended.