best type of vermiculite to use for vinyl bottom

What is the best type of vermiculite to mix with portland cement? Have been looking at "pool bottom "by Grace, aquaform or are the premix like prokrete better and easier to use? Any Input? Cost is also a factor. thanks chris

Hi, Chris,

When I was in the market, it seemed pretty generic. It seems I remember when I calculated the cost, mixing my own was markedly less expensive.

The premix gives pretty consistent results...we had a little trouble trying to get the mix consistent on each load. I think the water was more critical than the ratio, however.

If you're mixing a little, I'd use premix. If your mixing a lot (I think I used about 90 large bags) the cost overrode any convenience or consistency for me.

Hi again Chris (we've got to stop meeting like this ;) )
I can't tell you 'the best' because I've only used 1 kind (doing vermiculite bottoms in Ct and Va, both companies used the same one). The name is Whittimore and with a very few exceptions, has proven to be an excellent product. I have used the 'pre mixed' vermiculite and found it to be lacking in both trowel-ability and ease to mix. The key to getting good results is keeping all the mixes as close to the same ratios as is humanly possible (until a new 'mix guy' gets his 'eye for how the mixes should be, I mark 2 'fill lines' on a 5 gal bucket (the first for "fill to here 2 X' and the second for "then add THIS much") ) Hope this helps, any other ?s - just ask - Waste

Thanks to both of you for your input. Dave I see your in raleigh. I am in chapel hill and looking for a vendor to supply me. Who did you buy your product through? I need a large amount for the 18x36 bottom. Waste, the product you recommend is it specialized for pools and who is the manufacture so I can look for it? Chris

Chris, Whittimore is the big name on the bags, I'll grab one tomorrow and give you all the info from the bag.

This is likely OBE, but we mistakenly got the wrong kind of vermiculite and had to eat the restock fee. So if this helps you, great. If not, no harm.

There are three different grades of vermiculite. You want the MEDIUM grade -- NOT course, not fine. Joie