Vermiculite purchase in US/is verm. need to be pre-expanded?

[banjoduffman]

I'm in minneapolis, mn and just finished my dome/entry/vent/chiimney and and in final stages of the oven build (i hope). i'm trying to find vermiculite to purchase and don't know where to get it. Also, i saw that some verm. is 'pre expanded' which seems important? Any knowledge there? Also, i've seen verm. at home depot in the gardening section, will that mixed with portland cement do the trick to insulate? let me know pizza friends!

[david s]

Unless you have a furnace capable of heating the stuff to around 700C, get the expanded vermiculite. Nursery or hydroponic suppliers are a good place to get vermiculite. Once expanded it weighs around 10 kgs/100 litres

[banjoduffman]

Would this miracle gro work in your opinion? It’s apparently very hard to find much else...

[UtahBeehiver]

Have you tried trade stores that supply concrete block (AKA CMUs). Perlite is a common material used to fill cores of concrete block for insulation and usually sold in 4 cubic foot bags. You will pay a premium for the miracle grow.

[banjoduffman]

Utahbeehiver - do you know if that miracle grow link is appropriate to use even if it's expensive? I'm worried that since it's not expanded that i'll run into issues after i apply it then fire the oven.

[UtahBeehiver]

Can't say, I used trade perlite (abt 4 - 4 cubic foot bags for my build) for dome insulation only). FYI there are about 30 quarts per "1" cubic foot.

[banjoduffman]

found it! thanks for ideas my forum friends

[loganc10]

Not sure if you pulled the trigger on any of the perlite yet, but Uline is in your area and offers 8 cu ft of vermiculite for ~$70.

Typically they have a $25 will call fee for orders under $300, but I am also in a metro area that has a Uline and it is only ~$25 to ship, so that could save you the trip and be around $100 to your door.

https://www.uline.com/Corporate/About_Locations
https://www.uline.com/BL_3801/Vermiculite