Used widely in commercial construction for years, concrete floor systems have recently blazed trails into the residential market. The main reason is the growing popularity of stay-in-place insulating concrete form homes. A concrete floor works well with ICFs because concrete walls can carry the floor's greater weight without special provisions.
Four types of concrete floor systems are used in ICF home construction: concrete on steel joists, concrete on steel deck, concrete slab and joist, and precast concrete. On average the cost of these floors is $1 to $3 more per square foot than a wood-frame floor. But this cost differential narrows in designs with very long clear spans (over 20 feet). In addition, concrete floors provide many advantages over wood floors, including higher strengths, shallower depths, fire resistance and greater thermal mass.