After completing the various steps to prepare your lot for construction, we enter the foundation stage. As in the lot preparation stage, a number of simultaneous activities occur during this stage.
- Set up foundation footings & pour foundation walls
- Damp-proof foundation walls
- Install footing & under-slab drainage system
- Install under-slab (“ground-rough”) plumbing
- Pour basement slab
- Install retaining walls
Related Municipality Inspections:
- Foundation footing
- Foundation wall inspection
- Underslab plumbing
- Underslab mechanical
- Underslab electrical
- Basement floor slab inspection
Key Steps Explained:
The foundation consists of the concrete foundation walls and the footings they sit on. The walls themselves vary in thickness, depending on the height of the wall, and contain a web of rebar. The footings must be placed on ground solid enough to support your home as well as be below the “freeze” level for the locale (36 inches in the Kansas City area) so the heaving that takes place during freeze/thaw cycles does not impact the footings – part of why we employ the services of a soils engineer during the lot preparation stage. Once poured, foundation walls must cure for at least 7 days before framing can begin
In addition to footings and foundation walls, pier pads that are located within your home’s basement are formed and poured and are also considered part of the foundation efforts. These pier pads serve as structural load points and underlie where the structural engineers have indicated steel columns will be located during framing.
During the foundation curing period, we perform measures to manage the water that will constantly find its way around your home’s foundation and under your home’s basement slab.
In doing so, our first line of defense is damp-proofing. This entails spraying a hot-bitumus tar-like product on the exterior of the foundation walls wherever the walls will be below grade. This will give any water that seeps down along the foundation wall an easier path to the footings, where drains will await to take the water away.
At the base of the footings, both outside and inside the foundation walls, perforated drain tile is placed in a bed of gravel. It will be placed below the footings to catch any ground water as it rises and is connected to a similar drainage system that is inside the footings, which will capture any ground water that builds up under your home’s basement slab. This drain is either directed to a sump pit where a pump will take water away from your home, or to “daylight” where gravity removes the water.
The above discussion refers to managing exterior rain and groundwater. The next step in our process is about managing your home’s waste water. In order for waste water from the various sources throughout your house (like sinks, showers, tubs, toilets, washing machine, etc.) to be expelled, a network of waste lines is connected and located under the basement slab. This network of waste lines is referred to as the ground-rough plumbing and is installed at this point.
A basement needs a solid surface for its floor, and concrete is the material used as that surface. After ground-rough plumbing is put in place, it is covered with gravel, which forms the bed on which the basement slab will be poured. A vapor barrier is placed on top of the gravel to block moisture from seeping from the ground up into the home. The slab is then poured and it provides a solid surface on which to make a basement livable.
Depending on lot terrain and requirements, retaining walls may be needed for your project. If so, now is when they will be installed. Location and need for retaining walls will be dictated by grading requirements necessary to allow for positive drainage away from your home, and it also can be the result of a desire to make a certain area of your yard more expansive and usable.
The final step in the foundation stage is back-filling. This is the process of putting dirt back in around the exterior of the foundation, covering up the exterior footing drains and the damp-proofed foundation walls.
We now have a foundation in place on which to construct your home. So, on to the next stage, which is framing.