Insulation Board R value

[adders21]

Hi All,

I'm about to start my next project which is insulating our dorma walls.

They are about 2mtrs high before the roof line slopes them off.

I have already stuffed friction fit insulation I bought from Wicks in between the upright batons. My next plan is to cover over the insulation by fastening insulation board onto the outside of the batons creating a sandwich.

Which type of board has the best insulation R value at about 50mm thick?

How best to fasten the board to the upright batons?

Is it OK to slip the board up the sloping areas? i.e between the plasterboard and the roof membrane?

 

[tony1851]

1. Inch-for-inch, Kingspan / Xtratherm / Cellotex etc are the most thermally efficient materials.

2. Use screws to fix them to the studs.

3. Yes, but leave a sufficient air gap between the top of the insulant and the underside of the roof finish. Check your ventilation at eaves and ridge.