Coop Expansion Project. Flooring advice needed

If your budget is healthy, I would continue on the cement flooring for continuity at the same depth as the previous.

 

I have a lean-to with a dirt floor that I am converting into a 12x16 chicken coop. I thought about all of those same options and finally settled on an elevated wood floor. I am using pre-made concrete footings (from Home Depot - $8ea) with pressure-treated 4x4's and reinforced with 2x4's. Then covering it with OSB (plywood). You will need to either paint/seal the plywood or cover it with linoleum (which is what I am doing). Avoid the stick-on floor tiles, as the spaces between tiles can become a breeding ground for all kinds of nasty stuff.

Hope that helps, I'm sure others will have opinions too! Thanks goodness for BYC!

(Edited twice because, apparently, I can't spell today)

 

Personaly I would continue the concrete. It's fairly cheap $6.00 a bag. It only needs to be about 3" thick. Normal slabs and floors run about 4" thick. Put some plastic under the concrete for a moisture barrier. The tricky part is finishing it smooth. Brushing hides all the flaws but leaves a rough surface.
Then if you wanted, from there you could do a 2x4 floor to help keep their toe's warm.

 

I agree, in the long run you will have a consistent, safe surface and if you need a drain you can taper to it and install a rodent-proof cap with a removable cover for cleaning. We're lucky to be building our coop inside a barn with concrete floors, we topped the coop floor with planks which we had on hand, this will give more insulation and save bedding. I know some prople prefer not to use planks, but we'll sprinkle DE generously in the cracks, and having materials on hand (paid for) is always a bonus.