anO2ew ... (can't "quote as you're on a previous page)

There will be vertical, and then horizontal, EPS under the tray.
The vertical section will probably be nearer 125mm than 150mm to give an overhang/drip run or whatever.
The horizontal section will extend about 1m around the entire structure.
The site slopes in two directions so this is being left until the snow barrier (otherwise known as a roof) has been finished!

Posted By: fostertomSfunny, I replied to Mike but where is it?

Posted By: MikeRumneyWhat's causing the "insulation degradation"? contact

Simply your .005% proportional area - which I make 1.2% @ 2mm or 3% @ 5mm av cement-filled joint. Mind you I don't believe that proportional area principle - OK maybe for 50 wide studs interrupting 100 quilt thickness, but with 2 or 5mm wide conductive fins interrupting 200 EPS, I see the heat flows curving out sideways over an effectively wider frontal area.

I think I get this now ... "degradation" is of performance, not of anything structural/physical ...
Real-world experience of tour build so far is that whatever losses there are seem insignificant as so far the only heating required has been from people and appliances ... despite having not yet fitted the internal DG part of our big 3G non-opening rooflight

http://www.greenbuildingforum.co.uk/forum114/comments.php?DiscussionID=9565&page=1#Item_1