Drylining quandary/paradox

[oldbutnotdead]

Again at the House of Pain I have to insulate a few walls (cos Part L says I do)- can't do them from outside (one run is a party wall), can't really do dot and dab (walls are extremely unflat in several planes plus I need solid fixings for various things) so am going the stud and Kingspan route-effectively its a partition wall in front of a real wall. And yes I need millions of wedges to get the studs vertical- not a big deal.

My quandary is in setting out. Plasterboard over the top will be 2400 x 1200 sheets so plan was to set studs and noggins at 600 centres. But if I do this (using 2 x 2 on this particular wall), I end up with gaps between studs of 525 (from corner to 1st stud) and 550 the rest of the wall. Which is going to mean hacking lumps off 'standard' 600mm wide insulation boards or wasting about 10% of 2400 x 1200 insulation.

The other option is to set the studs for the insulation (ie 600mm gap rather than 600 centres) and end up only getting 2000 ish cover from a 2400 plasterboard.

Or am I missing something obvious and vital here? And no I can't use rockwool or any of the other soft products- I'm only just getting away with 50mm Kingspan on the U value sketch.

Cheers,

 

[themiddleagedun]

Set your studs to suit your plasterboard.
The offcut from your insulation can be used between the next studs, with another "make-up" piece to suit..

 

[oldbutnotdead]

Aye, that'll work on the 2400 x 1200 sheets, just as well I haven't shelled out on 600 sheets (can see BCO being impressed with all those 50mm slivers stuck together with gaffa tape )

 

[noseall]

On 50mm x 50mm studs you will require a minimum of 400mm c/c.

600mm centres is lunacy.

 

[oldbutnotdead]

Morning chap, ta for posting.

Does that 400 centres between studs and noggins apply even though the studs are going to be fixed to a solid (if shonky) wall at about 400 centres? It's not in an area vulnerable to physical damage and not really in an inhabited room (back wall of utility room) so thought I'd be OK.

And while you're there, I have some 4 x 2 stud and partition walls to do as well- is 600 centres pushing my luck with those also? (1 wall freestanding, fixed top and bottom, the rest fixed to brickwork all along the verticals).

(I've done a load of searching through here and elsewhere and there are all sorts of different answers to slightly different questions)

Cheers

 

[noseall]

I'm of the opinion that a gap of 550mm (space between stud edges) on a plasterboard wall is too great and leaves the board vulnerable.

Nothing to do with the strength of the stud, although this could be an issue also.

I am not a fan of 600mm centres of anything.

 

[oldbutnotdead]

Having done half the wall at 600 centres I'm inclined to agree with you- 550 square gap does look quite big. Framing is nice and solid though and hopefully the insulation will give some support to the boards and I'm doing the noggins at 400 centres now.

Again its not a high traffic high risk area so I'm not that worried about it but think I'll reappraise the other walls I need to do, especially the ones around the shower- don't want them flexing about the place.

Lets hope BCO doesn't get stressed about the percentage of wood vs insulation. Also just as well the walls are very wonky otherwise the 50mm insulation would be proud of the 47mm timbers! In fact for most of the wall height there's depth for 80mm......

Thanks again