Hi Bill, ten slabs each 14' wide and 6' long. So, the building g is about 14' wide by about 60' long. Each slab has 100' of pex. The top cantilevered past that. First floor about 11 or 12' high and the second or so level is above that.
With my job I could never fire steady so I gave up on heating it. It would take about a week to warm it up to about the mid 60's, the slab that is. In the middle of winter it would cool down in about two days.
I loved having a bit of heat in the shop in the middle of winter. Still had to dress up a bit but for working it was great. I just could not keep it going with my job. Not to mention that old age has caught up with me - slowing down. All my spare time was spent keeping it alive. It was nice turned out to be a big waste of time but when I retire from the factory it would be just the ticket.