Happy New Year! I was just thinking of upgrading the insulation in my loft. Now I do like the idea of sustainable insulation products, but value is also a consideration. B&Q have it on sale so I'd thought I'd compare the cost of the insulation. I am not sure if my Maths is correct or valid (please post and correct me, if not), but I thought the best comparison is the cost of what one square metre of 1 R-Value of insulation. If you know of other insulation options feel free to post their calculations.


Space Combi-Roll Loft Insulation (T)100mm
# Made using recycled glass bottles
# R-value 2.25
# Coverage: 13.89m²
# £13.49

£0.43 per 1m² of 1 R-value


Knauf Space Blanket Loft Insulation (T)150mm
# U-value 0.044
# R-Value 3.40
# Roll Area 1.97m²
# £5.99

£0.89 per 1m² of 1 R-value


B&Q Recycled Plastic Loft Insulation (T)200mm
# Made from 90% recycled plastic bottles
# Totally itch free
# R-value: 5.00
# Coverage: 1.48m²
# £7.49

£1.01 per 1m² of 1 R-value


B&Q Recycled Plastic Loft Insulation (T)150mm
# Made from 90% recycled plastic bottles
# Totally itch free
# R-value: 3.75
# 150mm thick
# Coverage: 1.96m²
# £7.49

£1.01 per 1m² of 1 R-value

http://www.naturalinsulations.co.uk/index.php?location=home

Guy , some good prices and selection of green insulation from this lot

Good idea to work out the cost of insulating a loft to a certain standard. The price seems to vary considerably. I'm just putting down a layer of Micafil as the joists are all over the place and it is the best way to fill all the voids. At around £10 a bag it isn't cheap though.

Hi jamesingram,
cost / area / R-value is the formula to compute money per square meter per unit of R-value.

good to see it come up at reasonable price against the lesser eco alternatives

Homebase has standard glass even cheaper

Space Combi Loft Insulation - 100mm
# Made using recycled glass bottles
# R-value 2.25
# Coverage: 13.89m²
# £9.99

£0.32 per 1m² of 1 R-value

Posted By: jamesingramdoes the BQ figures includethe BOGOF deals on at the moment?
cheers Jim

Yep I factored that into the calculations, so Homebase is better.

Looking for comments on "behavioural" comparison between Wool and recyc plastic bottles .....

Thought I'd revive this thread as the homebase/B&Q comparison ... (and the wool/recyc plastic comparison have changed a little, but basic relationships remain the same:
Homebase 170mm plastic Earthwool 170mm by 1140mm by 7030mm (same as coverage given above)... £7 or £3.50 if you can get the BOGOF
Homebase 200mm by 370mm by 4000mm: £6.93
B&Q ditto: £8.38
(Various wools: anything from about £5 to £9 per square metre of 100mm)

Mike
I went to Black Mountain Insulation factory a year ago, thye make recycled plastic insulation, sheep's wool insulation and now hemp insulation. I met the boss call andrew Evens, took time to answer all my questions, he said that Wool is great for buffering condensation compared to mineral wool. The recycled plastic he said was an honest product which wasn't as environmentally friendly but was better than consuming huge energy as per mineral wool. He thought the plastic/wool product wasn't very eco since it was difficult to recycel or compost, he said the B&Q product was just at a price point. Have looked up their product on theor site they complaints about thickness. Suggest speak to Evens and get his nput on comparisons, he may be biased to wool but at least its a start.

mike
I don't remember too much about their recycled plastic product I think you need to speak to Evens, he did explain for my house (Victorian) he woule recommend wool since it can absorb moisture he said the recycled plastic didn't have this capability. I installed the rpoduct myself, have to say it was the best product I have ever used, Evens told me to tear it across the roll with my hands rather than cut with scisssors, he promised it would tear perfectly, he was right took hardly anytime to install, good luck with your project. Always came out in a bad rash with the glass fibre took ages for it to go had to through my clothes out in the end cos no mater how much the wife washed them it was always there, will use wool on the next project, daughter is planning an kitchen extension!

best deals at the moment seem to be

B&Q - 3 rolls (single pack) of 170mm for £3.12 - (and if you buy before Thursday evening, there's 15% off)
Wickes - Knauf 150mm space blanket - buy 1 roll get three free (4 rolls for £13.98)

£3 a roll here and its delivered free. Its rockwool so a bit better thermally than glasswool.

http://www.npower.com/web/diyloftinsulation/index.htm

homebase are doing 3 rolls of 100mm earthwool (recycled plastic) for a tenner. I bought 12 for a job and have 9 left, so beware that it goes a looooong way.




*actually I do have a use for the extra, but I was still fairly amazed.

To update.

R-values are created by dividing the thickness of the material (metres) by the k-value for a particular material. So for Warmcel100 we get an R-Value of 2.5 at 100mm. If you can get it at only £3.11/m² then it's just 3.11 divided by 2.5."
UPDATED 25/2/14
Warmcel100
#recycled newspaper
#100mm thick (lose fill)
#£2/m2 for 100mm thick
#Thermal Conductivity 0.040W/mK. at bit better than standard mineral wall ,( 250mm=270mm glass fibre approx.)
#R-value 2.5

£0.80 per 1m² of 1 R-value