Polyester vs mineral wool loft insulation

barker77

Hi I am looking to insulate a loft that has almost no insulation in it. I was going to use standard mineral wool but came across this that looks interesting and wondered if others had considered or used similar ? Looking for decent environmentally friendly option thwt keeps the place nice and warm ! 

https://www.celticsustainables.co.uk/thermafleece-supasoft-polyester-insulation/

FreeBear

barker77 said:

Hi I am looking to insulate a loft that has almost no insulation in it. I was going to use standard mineral wool but came across this that looks interesting and wondered if others had considered or used similar ? Looking for decent environmentally friendly option that keeps the place nice and warm ! 

https://www.celticsustainables.co.uk/thermafleece-supasoft-polyester-insulation/

100x390x500mm (1.95m²) for £22 (plus shipping), or 100x1140x9725 (11.08m²) @ £31 for Knauf mineral wool (from Wickes). Bearing in mind minimum recommended level is 270-300mm, you are going to need a lot of the ThermaFleece, and regular fibreglass/mineral wool is going to be considerably cheaper. On price alone, I'd go for fibreglass - It also has the advantage of being non-combustible, where as recycled plastic will burn very nicely and release clouds of toxic fumes.

In principle, I'm all for recycling, but not in this instance.

Grizzlebeard

Bear in mind polyester is essentially equivalent to/worse than Grenfell cladding.

I don't know if there are flame retardant treatments that must be added by law, but if so toxicity questions remain (forever chemical PFCs.)

Indoor electrical faults(wires/junctions in/under thermal insulation) most common cause of accidental combustion.

Polyester is a plastic that only degrades over centuries, is not recyclable in spun form and is very bio-unfreindly.

In my view the "sustainable" recycled/eco tag is just marketing hype. Spun fibres/fleeces speed up the process (by centuries) of breakdown into micro and nano particles which can end up in our bloodstream, body and brains.

barker77

Thanks illl avoid the plastic! 

Grizzlebeard

barker77 said:

Thanks illl avoid the plastic! 

By the way, your original question is very sensible and one that should be considered by everybody.

I'm not knocking you for asking it, and I hope the thread will be helpful to others.

And not everyone is going to agree with me anyway and fair-doos to them.

Personally I think recycling is better than nothing, but not a long term solution. It sort of pushes our worrying about it into the future - like stretching a tarpaulin over a hole in the roof instead of replacing the tiles.

Brownie points for not reaching a conclusion in a vacuum.

MattMattMattUK

Grizzlebeard said:

I don't know if there are flame retardant treatments that must be added by law,

Even if they are added they are largely pointless, the way polyester burns once heated means that none of the flame retardants actually work on spun polyester, they barely work on polyester fabrics and even then only really to the extent that they stop a small temporary heat source from igniting the fabric. 

HillStreetBlues

I would have thought polyester would have a much less melting point than other material. I do wonder how long it will be about  once there is enough dripping plastic in a fire.