Be up there with those in the Know: use natural insulation
- Judith Leary-Joyce

- Oct 20
- 2 min read
The vast majority of builders will default to using PIR – a synthetic insulation – you’ll have seen it leaning up against a skip somewhere. Rigid foam with silver foil on the outside. It is very efficient, easy to get hold of and it will keep you warm in winter.
What the builder won’t tell you – and many don't even know - is that:
· PIR blocks the movement of water vapour, so is one of the prime causes of condensation in our homes.
· Gives off toxic gases when it burns
· It can’t keep you cool in summer
Not to mention that it’s made from petrochemicals, so awful for the climate.
There are loads of alternatives
There are loads of alternatives out there that are better for homeowners, builders and the home itself.
Natural fibres will keep you warm in winter and cool in summer, with no harm to the person installing them and they’re vapour permeable so don’t cause condensation.
Wood fibre: made from the remnants of wood when the tree has been used for everything else. Keeps you warm in winter and cool in summer.
Hemp: crops twice a year, grown in UK, holds loads of carbon. Keeps you warm in winter and really good at keeping you cool in summer.
Sisal: grown in UK. Easy to work with. Keeps you warm, cool and quiet – great acoustically
Denim: made from old denim jeans, cotton t-shirts and velvet. Warm in winter, cool in summer and great acoustics
Cork: highly renewable, warm, cool and acoustic
Diathonite: thermal plaster that can be put on to different thicknesses, internally and externally
Sheep wool: great use of a natural material, good for lofts. When all the cellulose has been removed, no risk of moths. (Note the lack of an S. That’s significant. Not all sheeps wool is treated this way.)
And here’s the latest one I’ve heard of: insulation made from GRASS! Incredible! Just waiting for my sample. As soon as I get it, I’ll show you on IG, so follow along
Pass this piece to anyone who’s planning work on their home. Builders don’t know this, so we need to use our buying power to bring them up to date.
And get rid of our cold, damp homes that cost a fortune to run.
New book coming soon: What the Builder Won’t Tell You.
End of November. Follow along for more
