Closed Cell Foam floor for bivy or tent?

If it's like the ThinLite foam from GG, it is very VERY fragile and would be totally inappropriate for the floor of a shelter. I can't even roll it up without putting my fingernails through it.

Here in the UK, Multimat sell 3mm/1/8″ Tent Underlay

I haven’t used it myself.

The stuff is fragile. I suppose you could glue some cloth to it, but being as it's so thin, that might defeat your purpose.

Why not make your bivy floor from a Walmart pad? Not the newer polyethylene one, but the older foam pad. It's durable enough for ground contact and would let you ditch your other pad.

it sounds denser than evazote that GG uses, so probably more durable. If you can find it cheap, go ahead and try it and report back. You could always rip the seams and replace it with silnylon.
If you are going to use silnylon on the bottom (not 1.1 dwr, which isnt waterproof), I would go with lighter evazote foam. You can get it from suluk46.com. Maybe use strategic pieces of velcro instead of adhesive in case of durability issues or if you want to switch to a different thickness. Please post pics when you finish, thanks.

Velcro is a good idea. I was thinking of sewing it to silnylon but then if water got between the two it wouldn't be easy to dry out.

It appears that Suluk's Plastazote is approx 1 pound/cubic foot- or half the density of this stuff. Maybe I'll try his stuff out since it's still very reasonably priced and lighter.

Hi Jim,

I use a 20×72'' 1/8'' volara pad for my bivy bottom. Provides a bit of extra warmth, and more protection than plastic drop cloth in my opinion. Not insanely durable, but I haven't had any problems. Mine is 3.1 oz.

I use Volara and it is very durable. I use the 1/4 inch thick stuff and have used my pad for a few years.