I know I don't update much - well asphodeline tends to put anything interesting up first!
Ok, some background . We've restarted insulating the loft before the weather turns cold and we start wasting energy heating the loft and sky above on cold nights. So I've been comparing prices etc on insulation (since we're cleaning out the remnants of the decaying original we're effectively starting from scratch - aside from the area we did, and floored over to provide storage space, when we first moved in.
So 100mm of new insulation between the joists then, if and when, we have the funds another 160mm plus over the top of that. So, in September I went looking to see what I could find
Single width (370/380mm) roll plastic wrapped space blanket 200mm thick by 4metres long £16
114cm - triple width combiroll 100mm thick by 12 metres long- £38 so triple roll it was.
Saturday we went DIY shopping for a couple of other items and stumbled across an insulation two for one sale.
170mm thick 114 cm wide 7 m long combi roll £28.98
200mm thick 37cm wide 4m long plastic wrapped space blanket £13.98
200mm thick 37cm wide 4 m long Ecowool insulation £14.98
Approximate area covered
Space roll 1.5m2
Cost per square metre
Combiroll £ 3.62
Space roll £ 9.45
Allowing for the special offer
Cost per square metre
Combiroll £ 1.81
Space roll £ 4.72
Ecowool £ 5.06
Given that they make a point about the Ecowool being 85% recycled plastic and using 23kilowatt hours less energy to make per roll (actually it's 'enough energy saved to run a 60 watt light bulb for 16 days') it seems a bit much to charge a premium - particularly as, if you read the small print, the space blanket roll infill is made using 85% recycled glass. I didn't examine the combi roll as closely but as all three products come from the same manufacturer I'd say it's a reasonable assumption that that contains a similar proportion of recycled glass as well.
I'm afraid that when public (and possibly spurious) ecological ethics meets pure costs - Well we've bought sufficient of the combiroll to cover the whole loft in at least 10” for under 40% of the other alternatives.
Now we've just got to finish laying it!