Most homes are built with basements or crawlspaces. When the home site has a high water table, ledge or other issues that might be problematic for a basement, a slab foundation with footings is probably the way to go.
Proper Design and Insulation
Make sure that the footings have enough depth and are poured onto pads to spread out the load. In colder climates, footings may need to go as deep as 6-7 feet to avoid frost heaving. Insulate both the exterior of the footing wall and lay down slab insulation over the gravel base to protect the overall slab from moisture and to keep temperatures within a minimal range. Install a French drain system around the perimeter of the slab to keep moisture from building up and causing cracks. Make sure your concrete contractor knocks the rebar form pins out before he backfills, otherwise your house may be subject to frost heaves. Refer to local code restrictions and state requirements for insulation and moisture control. For additional recommendations, see the Department of Energy’s perimeter slab insulation information.
Plumbing and heating
Radiant heat is the choice of many homeowners with slab flooring. Other plumbing—pipes, drains, septic relief ports will also be laid out before the slab floor is poured. If you’re laying out drainpipes that cover the length of you home, discuss including a mid-point access to make it easier to clean out the inevitable blockage. Make sure that bathroom, laundry and kitchen layouts are finalized and double-measured before the slab is poured, to avoid costly placement adjustments later on.
Benefits of a slab foundation
There are several benefits to substituting a slab for a full basement. There are less moisture worries during rainy or flooding seasons, and no need for a sump pump or dehumidifying system often found in basements. The slab will keep your well-insulated home cooler during the summer months. Some slab homeowners are quite comfortable in the summer without central air. The mechanicals (furnace, heat pump, water heater) can actually help to lower your heating bill when located on the main level. Heat produced by these appliances can be vented to upper floors or into north-facing rooms for efficient heat capture.