plasterboarding stud walls

[Fred]

Hi,

I was taught to support 12.5mm plasterboard at 60cm centres and 9.5mm plasterboard at 40cm centres. Are these strict rules or just rules of thumb?

I ask because I started to build a stud wall with studs every 60cm only to find that I have a "spare" 10cm at the end. If I had realised this at the beginning (and I realise I should have checked and double checked before building), I would probably have put the studs at say,

61cm centres and I am sure the extra 1cm would not have made a difference.

What I am now wondering is whether to put an extra stud at the end and have two studs within 10cm or whether just to move the last stud so that it is 70cm away from its neighbour. Would 70cm be too far? That's

70cm from centre to centre of the studs, which are 2 inches wide, if that makes any difference.

TIA

[John Rumm]

Just rules of thumb... in fact typically these days stud walls will be erected on 400mm centres and use 12mm plasterboard.

Keep the studs at regulation spacings so that the plasterboard will "fit" without needing and faffing about at the joins. Then add an extra stud at whatever smaller spacing is required at the end.

[Fred]

You are quite right, I posted without thinking (again). If I had moved the studs to say 62cm apart, I would have had a lot of plasterboard offcuts! But since the wall is not an integer multiple of 120cm long, I will have an offcut at the end, so I wasn't sure whether to have two studs 10cm apart or just leave the last ones 70cm apart.

What is the logic for using 40cm centres with 12mm PB? I'm surprised at that, I thought companies would try to save money by using fewer studs at 60cm centres?

[Fred]

Sorry, I should have made it clear that I always finish the plasterboard over a stud. I was typing faster than I could think and if I had moved the studs to say 62cm apart, I would have wasted a lot of plasterboard by having to cut it to fit.

Is there a recommendation of where to screw the plasterboard? Should that be every 40cm too?

[NT]

Every 6" is ok, but again practice varies.

NT

[NT]

The wider the stud spacing, the less the total timber cost for given wall stiffness (since 1 piece of thicker twice as stiff timber costs less than 2 bits half as stiff), but the thicker the PB then needs to be to maintain acceptable strength & sound transmission, thus the higher the PB cost. Also larger thicker heavier pieces of PB take more labour to fit. Naturally there is an optimum point where cost per performance is minimised.

NT

[Tony Bryer]

Australian practice is to dab the studs with adhesive every 300mm as well as nailing. A pain if you later need to remove the pb

[John Rumm]

Well if you are penny pinching, then indeed 60cm will be cheaper. If you are doing a decent job, and don't want bouncy walls that allow every fart to resonate though the house, then go for a more solid construction ;-)

[John Rumm]

I tend to do about every foot - so 4 screws across the width of a board.

[NT]

worth a read first:

[Fred]

Sorry for the late replies. A few posts saying 30cm ish, so there seems to be a consensus. Thanks.