Wondering for folks out there in colder climates dealing with heaving what a good low cost option for a slab would be? I'm in zone 6a in Nova Scotia, building a 36'x26' single story house, slab on grade with 10' icf walls. I've looked through a few different engineered drawings on some icf manufacturers sites and only see a 3 step pour method (footing, wall, slab) with frost protection. Is it possible and recommended to do a thickened edge slab with foam around the perimeter and underneath the slab? 1 pour for the slab and 1 for walls would be great if so. I'll be doing hydronic heating in slab. Anyway, any help would be great.

Doing that type of foundation is hard to keep from caving in and also not bearing on undisturbed ground because of how it is excavated. I am sure there are great people out there that do it daily and quickly that could make it work. I just would never do it myself. ICF house is very heavy but also very strong.

Look into the Leggalet system, may achieve what your looking for

Thanks, yeah that makes sense better to invest in a bit more work and concrete than a cracked slab.