[Greenbuilding] concrete & frost, green roof grids

[Joyce Coppinger]

Ask your concrete contractor what they mixed in to make the concrete
workable at temperatures at or below frost. If they mix in antifreeze, ask
him how this is a viable green approach.

And, if green roofs can be constructed and maintained successfully without
the use of plastic grid units, why encourage their use. Isn't this just
another use of plastic that could be eliminated so that the roof is truly
green?
-- 
Joyce Coppinger
jc10508 at alltel.net
402.483.5135, fax 402.483.5161