When building stem walls, block courses on footings are set below grade and reinforced with rebar before concrete is poured in a continuous pour for a seamless, integral slab. The blocks are then reinforced with rebar placed vertically in the holes or cells and filled with concrete.īlock walls can also be used to form stem walls that support a slab above. The process starts on the top of the footings with each row forming its own course. Reinforced Block and Concrete Wallsīlock foundations use cinder blocks (8 x 8 x 16 inches) that are stacked on each other and cemented in place with mortar. When using insulated concrete forms, they remain in place and insulate the home. The concrete will continue to cure and emit moisture for much longer. Temporary forms are usually taken down after one week, at which time the concrete is cured enough to support itself. Set-up time depends on the slurry used, the time of year, heat, and humidity. Concrete is then poured into the mold to form the walls.Ĭoncrete walls should be created as a continuous pour to ensure good bonding and avoid seam cracking where a first concrete layer has already set.Ĭement can be poured in place with a cement-pumper truck, or offloaded down the chute of a ready-mix truck if it can get close enough to the foundation. Once the forms are set, rebar is placed vertically inside the wall channel to support and add additional strength to the concrete wall once the molds are removed.
When pouring an integral foundation, aluminum or insulated wall forms are placed on the footings, clamped together, and supported to maintain their shape while the concrete is poured. Poured concrete is more popular for basement construction than block because it is seamless and resists water intrusion. A footing trench ranges from six inches to three feet deep, depending on the building size and soil characteristics. Footings provide a firm surface to resist sinking or shifting into the ground or substrate. These trenches are wider and longer than the walls they support and function like feet to distribute the weight of the wall and the structure above it. Footings are constructed in trenches dug beneath the level of the basement floor. Poured and block foundations both sit on concrete footings, or poured pads that serve as a base for the walls.