17 years ago
need a size of approx 4ft x 4ft x 16in. I want to use them to form a
void in a concrete pour. I don't care if they decay or rot later.
Any spray type insulations are more costly than the concrete they would
displace. Is there a cheap method to make a void form block?
Perhaps soemthing that is not a chemical reaction (maybe you could use
compressed air to make the bubbles in the foam). Perhaps a mixture of
soap and something that would harden + compressed air, inside a wooden
Any thoughts would be appreciated.