I am about to venture into topping up my insulation in my loft and relay the floor boards and need a couple of answers before I decide which way to go. I have a couple of options
A. To lay Polystyrene boards over the base 100mm joists then 18mm chipboards on top. Would 60mm of Polystyrene board be equivalent to 170mm of loft insulation and would it with chipboard on top support walking on ok.
B. I have three 5"x2" Joists running from one end of the roof over the 100mm rafters. If I was to install another 5"x2" joist and lay chipboard on top how much clearance would I need between the chipboard and insulation.
A. To lay Polystyrene boards over the base 100mm joists then 18mm chipboards on top. Would 60mm of Polystyrene board be equivalent to 170mm of loft insulation and would it with chipboard on top support walking on ok.
B. I have three 5"x2" Joists running from one end of the roof over the 100mm rafters. If I was to install another 5"x2" joist and lay chipboard on top how much clearance would I need between the chipboard and insulation.
