Drylining a stud wall, PB orientation?

[jackg]

Which way is a sheet of PB screwed onto a stud wall, long side horizontal or vertical?
I thought vertical but I read a couple of Australian articles and a UK one which state horizontal. The same as as boards on a ceiling, i.e. right angles to the joists.

I have to board two external walls, studded out and infilled with board insulation and then 25mm insulation on top as wood is a poor insulator.

 

[roy c]

Stand them on their edge and if you have a gap at the top, get two pieces of wood and put one long ways on and the other on top of it and lift board on top of second piece of wood and lift it up with your foot till board touches ceiling and put a few screws either side of board then take your pieces of wood out and screw the board and so on with the other boards... Cut boards to suit studs...

 

[endecotp]

How high is the wall?
If you can use single sheets vertically, do so. (2.7m and 3m boards are available, though not as easy to find as 2.4m.)

 

[jackg]

How high is the wall?
If you can use single sheets vertically, do so. (2.7m and 3m boards are available, though not as easy to find as 2.4m.)

2.25m