Hello! I'm working on drawing up my plans for a tiny house/cabin built on a cement pad. I'm trying to figure out what to do for my flooring. I've heard that using car decking, because it's so thick and hardy, can be used both as subflooring and flooring. This house is not a "live in" house- more a get-away cabin for the weekends. I'll be using treated lumber for the floor joists and put a vapor barrier between that and whatever flooring I decide to use. Any suggestions or documentation on car decking as a floor? I feel like this would help save on costs so I don't have to get both subflooring OSB or plywood and a finish floor. Thanks!

I have used car decking, or tong and groove as many sawmills call it as both the floor of a loft and the ceiling of the room below in log homes.The 2" thick (really 1 1/2") works well and can span up to 4' between supports although I try not to go that far. The only problem is that it is usually made from soft wood, pine or fir that can scratch or dent when firnachure is moved on it without care.

Fred, when you used it without any subflooring did you have any other issues other than scratching from furniture? Weather proofing, wind proofing, etc?  Thanks!

No but l was using it between to indoor spaces. If a vapor barrier is used under it l don't think you'll have a problem. One thing to watch is that it is dry when installed or it will shrink and open cracks between the boards when it dries. I find that using screws rather than nails angled back into the boards threw the tongue made it possible to straighten boards that were a little twisted or bowed and still not have the screws exposed.