Studded Wall And Kingspan

[chojin360]

Morning

i have an external cold wall so im putting up some studding , filling with "something" and then plasterboarding over.

I have gone and bought a load of 2*2 to start making the frame and this is where the fun has started

i have built the outside of the frame as a starting point and then my dad threw a spanner into the works.

the problem i have is that although its 2*2 timber when you actually get the tape measure out its only about 42-46mm

SO..........

when you get kingspan/celotex in a 50mm thickness - its it actually 50mm or more like 45mm ??

obviously i cant put a 50mm sheet into a 45mm space

any ideas at this point , or is the kingspan thinner thatn specified ???

if it is 50mm then i will have to use rockwool slabs as this will compact slightly ( i will only have to crush it 4mm at the end of the day ) - but i was going for kingspan purely down to its thermal properties

any suggestions welcomed at this point as work as halted

Stu

 

[freddiemercurystwin]

See if you can get 40 or 45mm thick Kingspan, they make it, just depends on your local stockists etc

 

[chojin360]

they do !!!

ahhhhhhhhhhhhhhh well that helps - i thought they only stocked standard sizes of 50mm 75mm etc..

i got some measured up before in a shop - and they were selling it as 3 inch wide - but it was 80mm - so thats bigger than spec'd ( as it would be around the 75-76mm mark )

hummm will do some more digging around

 

[chojin360]

i have spotted this

http://www.cwberry.com/Inquiry_ProductDetails.aspx?ItemNumber=02250088

but not 100% sure if it is suitable for the job

or there is this ( which i wanted ) but they dont seem to stock it in 40-45mm sections

http://www.cwberry.com/Inquiry_ProductDetails.aspx?ItemNumber=02250067 (Thermal conductivity 0.023 W/mK)

would the first one be suitable ??

or do i just go with ...

1 - rockwool slabs
2 - cheat and put a 5-7mm strip onto EVERY studd

stu

spotted this aswell ( rockwool stuff ) :

http://www.cwberry.com/Inquiry_ProductDetails.aspx?ItemNumber=02250240 (Thermal conductivity 0.038 W/mK)

 

[^woody^]

Put your 50mm kingspan between the studs. It does not matter if it is proud slightly as the plasterboard will still fit across and can still be screwed in the studs no probelms.

But practical terms, you will most likely find that when you come to fit the studding, you pack it out to get it plumb, so you end up with a deeper space in any case. Or apply some gripfill between the stud and the wall and this gets you a few extra mm

 

[chojin360]

the only thing that worried me is on the edge of the plater board - would it not crack

but i suppose you just dont go mad screwing it in

the wall was flat anyways ( its already been plastered many moons ago - so the studding has fastened to it no probs ) with no need for packing out

hummmmm like i said - ideally i want the 50mm stuff - if im doing this once - i want it as thermally efficient as possible ( without loosing too much from the room )

thanks for the info woody - it did cross my mind about just putting the board over the kingspan but its nice to hear someone elses view on it !

 

[mattylad]

Pack it out with some slats of the required width etc.

You can get them made easily by going to a wood yard, buying enough 3x2 & getting them to trim it all down. then just tack them to the uprights.

 

[chojin360]

so as a general consensus whats the best idea

1 - use rockwool - with no messing just shove it in
2 - use 50mm with padding on the studs
3 - use 50mm without padding on the studs

the plaster board used will be 12.5mm and im putting up the smaller sheets ( 1800* 900mm ) and will be screwed into the studs and then it will be skimmed over

Stu

 

[^woody^]

Use 50mm Kingspan which will be the best insulation.

The plasterboard is supported by the kingspan and will not crack where it's nailed to the studs.

I would just do it and not over complicate it or worry too much

 

[chojin360]

sounds like a plan to be honest

will get some ordered up and delivered and see what i can do from there