Loft Insulation - multifoil or rigid board??

[spartacus]

Hours spend searching the intranet and just found this site ...

I'm converting my loft and have got to the thorny issue of how to insulate the external walls (37 degree pitched, 100mm rafters, plain concrete tiled) and flat roof (200mm joists, 18mm plywood, fibreglass layer)

Do i go for
1 between and over rafter rigid board insulation with plasterbaord
2 between rafter insualtion with insualted plasterboard
3 multifoil overrafter insualtion with plasterbaord on counter battens

Advice / recommendations appreciated - or link to previous threads if i have missed previous discusiosn / debate.

 

[ipjodan]

Hello,

Just done mine, building regs wanted 135mm total of rigid board. I went with 100mm inbetween rafters and 40mm under rafters, then plasterboard. oh i used breathable felt aswell. Have a look here

http://www.insulation.kingspan.com/uk/literature.htm

Joseph