loft insulation under boarding without roll???

[Basher67]

Hi I have jsut ripped out my bathrrom to redecorate, including the ceiling. When I took the old ceiling out I lost all the tatty old loft insulation.

Now I want to board above the bathroom in the loft so do not want to use traditional roll insulation (plus I have halogen downlights which arent fire reg, so think they may be a worry against roll insulation).

Is there any sort of board insulation I can use which I can cut out sections for the lights. Something like: Kingspan Thermapitch TP10 Roof Insulation, if so what thickness would I require to have the equivalent of 270mm roll?
Any help would be gratefully accepted, I am only a self taught DIYer

 

[mointainwalker]

All common fibre-wool insulation is non-flammable ( when I checked this in a shed, they rang manufacturers who said burns at 1200 C )

All the boards will burn brightly so the wool is much better for safety.

Unless you have a vapour barrier between your bathroom and your loft -ESPECIALLY with those lights - you are guaranteeing the transfer of much moisture-laden air which will condense in the cold loft and make it dripping wet.

Bad thing