Attic insulation top up

stedeb

hi all
not sure if this is right thread (sorry if its not)
im looking to insulate the attic
house is 33 years old so insulation allready up there smells musty
i have2 questions

1. do i remove this and lay fresh down (fibergalss ) or just put it over whats allready there .

2. how much would i need i assume 200 mm will be ok attic is 28ft long by 20 ft wide joists are 23 "apart

thanks
stedeb

RKQ

stedeb wrote: »

1. do i remove this and lay fresh down (fibergalss ) or just put it over whats allready there .

It depends on its condition really. If it still "fluffed" out and dry then I'd leave it in place.
Fibre glass is relatively cheap so its your call.

stedeb wrote: »

2. how much would i need i assume 200 mm

I'd advise 300mm thickness or at least 250mm.
Assuming joists of 150mm or 6 inch high. Put 150mm fibre glass between joists with a second 150mm layer on top, laid perpendicular to the joists (at 90 degrees)
Take care not to block ventilation to the attic - which could cause dry rot.

There are a number of threads on this issue on the Construction forum.
Hope this helps.

stedeb

thank rkq
IM thinking of replacing whats there can the old stuff be put in skip or local recycle ctr?

hopefully this will keep it nice and cosy this year
thanks stedeb