Is celotex a better alternative to foam spraying loft?
- Thread starter fitzykev
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I doubt that the benefit (if any) of insulating the rafters as well as the floor/ceiling outweighs the cost.
possibly boarding the loft on top of the insulation and not crushing it may be better.
possibly boarding the loft on top of the insulation and not crushing it may be better.
To board the loft means supporting the boards such that they don't compress the insulation. So either more timber, or posts you can buy for the job.
In our house, a previous owner has insulated between the ceiling joists and boarded over - but also insulated between the rafters. To just insulate the ceiling would mean losing so much height that I'd only be able to crawl - at present I can just manage an ape-like stooped walk. As a side effect, the loft doesn't get like an oven in summer (handy for the electronics, TV dist amp and network switch, up there), or a fridge in winter.
I'm not too worried about condensation in the timbers - it's glass fibre so quite porous, and the roof is slates (with cement sarking where it's still in place) so no shortage of ventilation.
At our last house, in a couple of the upstairs rooms I pulled down part of the ceiling so I could put "celotex" between and under the rafters of the sloping section. I left a gap above the insulation, and it had a modern breathable membrane. The insulation came from Seconds & Co at a massive saving compared to buying full spec stuff from the builder's merchant.
In our house, a previous owner has insulated between the ceiling joists and boarded over - but also insulated between the rafters. To just insulate the ceiling would mean losing so much height that I'd only be able to crawl - at present I can just manage an ape-like stooped walk. As a side effect, the loft doesn't get like an oven in summer (handy for the electronics, TV dist amp and network switch, up there), or a fridge in winter.
I'm not too worried about condensation in the timbers - it's glass fibre so quite porous, and the roof is slates (with cement sarking where it's still in place) so no shortage of ventilation.
At our last house, in a couple of the upstairs rooms I pulled down part of the ceiling so I could put "celotex" between and under the rafters of the sloping section. I left a gap above the insulation, and it had a modern breathable membrane. The insulation came from Seconds & Co at a massive saving compared to buying full spec stuff from the builder's merchant.
I'm not an expert, just diy.
It sounds like you have what is what is called a cold loft. The loft is supposed to be ventilated, and therefore supposed to be cold. So the insulation goes on the floor of the loft, between and on top of the ceiling joists to stop heat rising into it. The insulation doesn't go between the the rafters which support the roof.