@kmkane... The "old thread" comments, at least from ME... aren't for any other reason than letting some contributors know, that the advice they might believe they are giving, may be moot. I know that when I 1st became involved on Houzz, I was glad when someone indicated that I may be addressing a question which had probably been answered months (if not years) ago. Helped me "learn" to check the original posting date before blathering on about an issue someone was no longer interested in.

Do you want to keep the wood floor? It is rare to see wood floors as garage floors. I've seen homes like this moved onto pour basement slabs (same concept as pile foundation...but with a basement instead of dirt. If you want to keep the wood, then there has to be a way to keep the wood off of the concrete. An 18" crawl space (dirt covered with 6mil poly sheeting or cement) is always an option. The 18" crawl space would have to be cross vented/heated properly. This is for "keeping" the wood. Flooring. I'm not sure what has to be done to remove the wood floor and have the building sit (joists and all) on concrete. Remove the joists and you have plenty of stability problems. You would need to speak with a local architect/building engineer who has some knowledge of what you are trying to do, soil conditions, etc. to get this right. In theory it can be done (we've just landed a small car on a comet...we should be able to put an old building on a cement slab)...I'm wondering about the expense to get it there (excavation + soil stabilization + concrete + piles, etc).

Thanks everyone for the warnings. Honestly I had not thought that could be possible so just in case I'll gear up with a mask to avoid inhaling any of it. I will still need to remove it, but from what I read the problem with asbestos is if you sand it and make it into breathable particles, so ripping it out should be ok. I've looked up in youtubr and there seems to be a tool called mastic remover that you can put on your floor sander and it would scratch the surface removing any of that stuff.

after watching my daughter and her husband agonize over the way their expensive timber floor has not held up well after 3 years, I would recommend tiles/wood look tiles with under heating. Their beautiful warm expensive floor looks like it always needs a clean and polish, not from neglect, they have cared for it well. One of the boards now has a slight and painful moan when it's stepped on :-( I grew up in a completely wood floor home and although it looked wonderful, my Mother hated it. ....and the mats ! Wood is a lot harder to maintain than tiles ,(no matter what the die hards say) the modern wood finishes are much better than they used to be.... But a piece of wood is rather arty no matter what it's used for and it does demand to be loved and cared for.....and if something goes wrong it's a lot more expensive to fix than sand and cement. Ultimately you have to be happy. BTW underheating tiles is warmer than timber :-)