Frost Heaves and the Leaning Towers of Doom

Tom:
I am contemplating adding a small addition to my home - - a small rusticcape (approx 24'x32') with a standard poured cement wall foundation. Thesurrounding area is all ledge w/approx 2-3' of topsoil. I plan onbuilding the two-level addition (20 x 24') on a slab to be attached to theexisting foundation via a small entranceway. This would place the additionat ground level to access the existing driveway. In short, this soundslike a perilous adventure here in Maine. Is there any way to pour a slabaddition so that it will remain solid and stationary after a few harshwinters? I recall a program where Dr. Hill gave a good discussion offrost effects and how to avoid most common problems (since lost in my agingmemory bank). The Maine landscape is replete with many a 'leaning tower,'and additions that have since 'danced' away from their intended location.
Thanks!
Tim
Winterport, ME

Hi Tim,
You can get a copy of the paper that Dick wrote on frost heaves, bycontacting the Dean of Engineering's Office at UMO.To answer your question: I would remove the layer of topsoil, put down alayer of compacted crushed stone with good drainage, insulate and build ashallow frost protected slab.
Look over the paper. It covers all the basics. Also check in with somecontractors and see what they have to say. Ledge is usually stable. Theissue is to segregate the slab from the ledge, thermally, so the floor canstay comfortable without moisture issues.
Tom