How well does vermiculite insulate compared to fibreglass, PIR, etc?

[Krome10]

Hi all

I've already got vermiculite in the loft, but only to 100mm or so (varies quite a lot)... I'm currently reboarding beneath my header tank and got a few other jobs to do up there, but will soon want to add additional insulation.

Does anyone know how vermiculite performs compared to the usual suspects? I've had a quick look online and come up with nothing so far. It would be really helpful to know so that I can decide what else to add up there, where to put what, etc.

Many thanks for reading.

 

[Inspector]

Be careful around that stuff. It has asbestos in it and that means the dust will mess you up.
One search said it has an R value of R2 compared to fibreglass which is about R3. Now those numbers are the system used here which may be different than yours. It is different from the Aussies.

Pete

 

[Phil Pascoe]

He's in South West Wales, not New South Wales.

Vermiculite is beastly stuff and a pain in the jacksie if you have lath and plaster walls - it finds its way down through them.

 

[Fitzroy]

Vermiculite is about 2/3rds as good an insulator as glass fibre roll. So you’d need 6” of it vs 4” of roll to give the same insulation. It’ll depend on available depth and installed cost to decide which is best. Personally I’d go with glass roll as it’s easier to handle, assuming your doing it yourself.

 

[clogs]

it's not better than rock wool but it does get into the corners better than wool so more efficient overall....
if u want to be green there is real wool from sheep hahaha, that is fire proofed and on sale.....
if I was starting over thats the route I'd take.....
when I was looking at insulation in the UK, roof insulation (ceiling) 6" was recomended but at the time in Sweden 14" was the min standard.....
I was lucky enough to buy industrial type rockwool when I lived in France...
12" thick was the equiv of 24" of the domestic type.....
I found that doing it once properly was far better in the long run.......
double up the thickness if u can, esp now with the high price of gas......