I'm looking to insulate my loft with 100mm depth (glass mineral wool, wickes loft roll insulation base layer). However, my joists are 330mm apart whereas the roll is suitable for 400mm and 600mm apart. Can I still use it? ie. can i put the 400mm width into 330mm, or should I look for a wider piece and cut to size?
also, has anyone used the wickes loft roll insulation? if yes, how does it perform?
many thanks in advance.
on top of the joists, i intend to use slabs of insulation with chipboard on top.