Vermiculite

[wildoats]

Does anyone know if there is any difference between the Vermiculite that is sold for masonry insulation purposes -- to use in an evaporator vs. horticultural vermiculite used for gardening?
I looked online and I asked my local maple sugaring supply dealer and I haven't been able to find/get an answer.
The vermiculite sold for horticultural purposes is about half the price, which is why I am asking.
Thanks for your help

[Bricklayer]

It's the same stuff. I buy it all the time from a garden supplier by me. For lightweight concrete mixes and high heat concrete mixes. And typically horticultural supply stores have it in larger bags for cheaper. I also use perlite sometimes. It looks like white pebbles. Same characteristics as vermiculite. If your using it in an evaporator make sure you cover it with something like sand or fire blanket or it will und up blowing around inside and out the chimney.
Vermiculite and perlite are used in potting soil mixes to hold water and I would assume some type of fertilizer when it eventually breaks down. So just make sure your buying 100% perlite or vermiculite. It will say on the bag.

[maple flats]

Both the same. If you are doing an arch that calls for enough vermiculite to add up to a big price tag, find a greenhouse supplier. When I did my 3x8 raised flue I priced the biggest size Lowe's had and figured how many it would take to fill the void. The total came to nearly $500, then I called a greenhouse supply and it only cost me $45 and with that I actually had some left over. Some use sand, but beware how heavy that will be, many arches will not hold that much weight if you have a raised flue, if drop flue you'll likely be OK. Ask the manufacturer first.
I bought mine from Milikowski Greenhouse supply in Syracuse, they were bought out by Griffin Greenhouse, I don't know if anyone has bought them out. They both had doutlets in about 5-6 places in the northeast. They will have fine and course, either works well. For the good price you need to buy big bags, I think the 2 I bought were 6 CF each.