Our sitting room is on the ground floor of a Victorian semi. The floorboards were replaced some time ago (before we bought it) with rather nice hardwood boards, and my wife does not want to carpet it. The room is quite cold - in part because it has two external walls, and also because the floor is uninsulated. Having raised a couple of the floorboards with the assistance of my builder, I have discovered that the joists are just 3" deep, and the airgap underneath is just 90mm or so (at the edge of the room, anyway, where we lifted the boards). The room is about 5m x 5m with a bay window.
I have picked up advice that breathable insulation is massively preferable to rigid polyurethane of the Cellotex/Kingspan type and had been thinking of using Hemp Flax Thermo Hemp Combi Jute, with recommended membranes and tapes, as supplied by Ecological Building Systems.
Having looked at building regulations and the requirement to achieve a U-value of 0.25w/m2K, however, I am not sure (based on some of the online calculators) if that can be achieved at all using these natural insulation products - nor rock wool, for that matter.
Does anyone have any ideas about a best way forward? Where the building regs say that they cut in when insulating more than half of a "floor", does anyone know whether that refers to the floor of a room, or the floor of the whole footprint of the building? If the latter I could still go ahead without being in breach of building regs - although perhaps it wouldn't be worth it.
Some advice I have read here and elsewhere suggests that replacing solid floors is the way forward. I am not greatly attracted to that approach, but perhaps it is the only way to improve floor insulation significantly while not setting up all sort of damp issues by using Kingspan etc, or breaking building regs?
I have picked up advice that breathable insulation is massively preferable to rigid polyurethane of the Cellotex/Kingspan type and had been thinking of using Hemp Flax Thermo Hemp Combi Jute, with recommended membranes and tapes, as supplied by Ecological Building Systems.
Having looked at building regulations and the requirement to achieve a U-value of 0.25w/m2K, however, I am not sure (based on some of the online calculators) if that can be achieved at all using these natural insulation products - nor rock wool, for that matter.
Does anyone have any ideas about a best way forward? Where the building regs say that they cut in when insulating more than half of a "floor", does anyone know whether that refers to the floor of a room, or the floor of the whole footprint of the building? If the latter I could still go ahead without being in breach of building regs - although perhaps it wouldn't be worth it.
Some advice I have read here and elsewhere suggests that replacing solid floors is the way forward. I am not greatly attracted to that approach, but perhaps it is the only way to improve floor insulation significantly while not setting up all sort of damp issues by using Kingspan etc, or breaking building regs?