Wall framing / Studwork

Hi

I'm just in the process of calculating what timber/gyprock is required to build 30m of internal wall.

I assumed I'd just use 450mm centres, but the dilemma I've just stumbled across after looking at plaster board dimensions is that the 2700mm sheet is considerably more expensive.

Apart from the extra stud and a bit more time is there any other reason for me to consider the 450 over 400 option?

2700x1200 with 450 centres
or
2400x1200 with 400 centres

Cheers
Alex

You are aware that the sheets get laid horizontally ( usually ) so you need to look at individual wall lengths then allow for two sheets high ( 1350mm wide sheets ) ?
That also means you have to be aware of what sizes the 1350mm sheets come in.
You can also drop your stud spacings back to 450mm.

Stewie

I realise it needs to be layed horizontally, but my point is that if I get 2700mm long sheet it fits 6 studs at 450mm centres, where as the 2400mm sheet would give 5.33 studs at 450mm centres. I assume the 2400mm sheet is made for 600mm centres? I'm not sure I like the idea of 600mm centres.

Ceilings are 2420 and 2520 depending on where in the house, we'll be coving the ceiling so doesn't matter if it's slightly short.

I thought it'd be easier to just get the same board throughout and join rather than try to to order for specific walls?

Plasterboard walls can be jointed off stud (mid-span) if the joints are backblocked (this a bit more work)
Personally I would use +3.6m sheets (as long as you can handle) & cut the sheets down to length as plasterboard is relatively cheap. This will reduce the amount of flushing.

I would use 450 stud spacing as wall insulation batts are available in 430mm widths. If you use 400mm spacing, all the insulation batts will need to be cut down to size.

That's what everyone in the trade does ( less work, less waste ). As long as you can get the bigger sheets into the rooms ( those 5.4's are a pain to handle! ).

Stewie

Thanks guys, I hadn't thought about the insulation size.

Looks like I'm off to work out exactly how many of x sheets I'm after...

What is backblocking in this context?

Back-Blocking of Butt Joints on Walls
• Sheet ends should be neatly cut and butted together within 50mm of the centre line between the studs.
• Nail strips of plasterboard to the sides of the studs to support the back-blocking over the full length of the joint. Position so that the face of the back-block will finish 5mm to 9mm behind the stud face.
• Cut back-blocking to fit neatly between the studs and fix by skew-nailing the edges back to the studs.
• Apply Base Coat or Cornice Cement to back-blocks.
• Fix plasterboard wall sheets in place.
• Depress sheet ends at butt joint with battens and packing such as nails to form a 2mm deep depression.
• Allow the adhesive to set for a minimum of 24 hours before removing the temporary battens. A hollow formation suitable for jointing remains.

The above instructions were taken from a plasterboard manufacturer's web site. They also have diagrams on their web sites.

However backblocking if very easy if the wall has only been sheeted once side as you can get around behind the sheet. In this case you temporarily fix a batten to the front of the butt joint (to keep the end of the sheet flat), Walk around to the back of the wall and glue (using base coat or cornice cement) an offcut of plasterboard over the back of the butt joint & temporarily pin this off-cut in position while the glue sets.