dcarch, believe it or not, I did think about using the floor for a heat source
And I also have snagged a large black watering trough (sp) to go in there.
So after playing around out there, I thnk I'll go with the pea gravel under my plant tables and potting up area and then use pavers in the rest of the space.
Now why do you use the pea gravel over say...No. 8's or a larger size of gravel?
And Sherry, I like your new greenhouse a lot but the walkway in your small greenhouse is really cool.