Hi
I’m new to this forum so any advice would be much appreciated!
I’m looking to upgrade the insulation in my loft. It’s above 3 bedrooms in the original part of my house (built in 1860) which had a new roof in 2007.
The roofer laid multi foil over the rafters but no insulation was installed between the rafters or joists, which are both 140mm depth. Other than that it’s a fairly typical structure with tongue and groove chipboard flooring nailed to the joists, plasterboard fixed to the underside of the joists and ventilation at the eaves. We’ve never had any problems with damp/mould and it’s all in really good condition.
Due to the joist depth and lack of head height, I am planning to lift and reuse the chipboard (which is nailed but not glued - my research tells me that punching the nails right through into the joists is the quickest way and will minimise damage to the chipboard?) and use 100mm depth PIR with gapotape between the joists, leaving a 40mm gap between the PIR and plasterboard, which I’m hoping will give me clearance for the down lights and cables, and provide an air gap.
I’m also thinking of raising the joists by 50mm and installing in the same way to give me 150mm PIR.
I’m a bang average DIY’er but have spent ages looking into this and keen to get (and would very much appreciate) some advice/help.
Many thanks in advance
Adam
I’m new to this forum so any advice would be much appreciated!
I’m looking to upgrade the insulation in my loft. It’s above 3 bedrooms in the original part of my house (built in 1860) which had a new roof in 2007.
The roofer laid multi foil over the rafters but no insulation was installed between the rafters or joists, which are both 140mm depth. Other than that it’s a fairly typical structure with tongue and groove chipboard flooring nailed to the joists, plasterboard fixed to the underside of the joists and ventilation at the eaves. We’ve never had any problems with damp/mould and it’s all in really good condition.
Due to the joist depth and lack of head height, I am planning to lift and reuse the chipboard (which is nailed but not glued - my research tells me that punching the nails right through into the joists is the quickest way and will minimise damage to the chipboard?) and use 100mm depth PIR with gapotape between the joists, leaving a 40mm gap between the PIR and plasterboard, which I’m hoping will give me clearance for the down lights and cables, and provide an air gap.
I’m also thinking of raising the joists by 50mm and installing in the same way to give me 150mm PIR.
I’m a bang average DIY’er but have spent ages looking into this and keen to get (and would very much appreciate) some advice/help.
Many thanks in advance
Adam
