eclane, I have posted the above to ideas, per your suggestion. We did use expanding foam to fill any void in the foam. The nice smooth 1/4 round edge is achieved using a side walk edging trowel. This ad photo will give you the idea, mine is an old heavier cast magnesium one. I'll get around to the carpets later. Thanks, Ric
OOPs forgot, we cured the concrete about a week before etching it with a mild muratic acid.