In summary: T-shaped foundations are used in areas where the ground freezes. First, the footing is placed. Second, the walls are constructed and poured.
The footing must be level and must extend past the edges of the hole so that it can support the weight of the building. After the footing has been created, the foundation walls can be built. The foundation walls are usually made of concrete, but they can also be made of stone, brick, or wood.
Contractors regularly look at the basic U.S. residential concrete foundation as being a three-day process. Excavation, footing forming and concrete placement on day one; wall forming and concrete placement on day two; and form stripping, clean-up and waterproofing on day three.
Between your foundation walls and resting on top of the footings lies your foundation slab: the giant piece of concrete which makes up your basement floor or subfloor. Each of these pieces must be poured and cure one at a time: a process that can take up to a week for each step.
As the name suggests, footings are in contact with the ground, reinforcing support to individual columns. Foundations, on the other hand, can be thought of as the leg of a building, transferring the load between the footing and whatever structure sits above it.
Once the footings are set and pass inspection, a contractor will pour the concrete into the home's overall foundation. This could entail anything from a slab to crawl space to a full basement. The foundation is the backbone to everything else we discuss below, which essentially rests on top of it.
Slab foundation: Slabs can either sit directly on the soil or on shallow or deep footings.
A Monolithic Slab Foundation
Unlike floating slabs or traditional footings, a monolithic slab is poured as one continuous piece, with both the concrete footing and floor formed simultaneously.
The footings range between $10 to $15 per linear foot installed. This does not include the prices of the crawl space walls, only the price of the concrete foundation. The average concrete block wall adds another $6 to $7 per linear foot, for a total crawl space price per linear foot of $16 to $22.
A minimum of 12”inches deep for all footings and the width will be determined by the amount of stories, 12” inches for a single story, 15” inches for a two story and 23” inches for a three story. This is based on a soil bearing capacity of 1500(psf).
In theory, yes, pouring concrete over concrete is possible. Typically people want to pour concrete over old concrete because their existing surface is slightly damaged, faded, or just outdated.
Footings pouring one day to setting forms on walls is always under your discretion, 48-72 hours is plenty of time for the footings to set/ dry… But just make sure you have everything else ready for the slab after walls (including entry / exit points on the walls themselves).
A footing is placed below the frost line and then the walls are added on top. The footing is wider than the wall, providing extra support at the base of the foundation. A T-shaped foundation is placed and allowed to cure; second, the walls are constructed; and finally, the slab is poured between the walls.
Pile driving, demo, excavation is by far the loudest.
Since it only gets support from the ground directly underneath, it's not ideal for use under larger structures, like entire homes. Unlike a slab-on-grade foundation, which is more common in home construction, a floating slab doesn't sit on footings that sink further into the ground for more reliable support.
Slab foundations: Generally less prone to pest infestations but can be vulnerable to termites. Moisture issues may be less visible but can lead to mold growth if not addressed. Crawl space foundations: More susceptible to pest infestations and moisture problems if not properly maintained.
Pros and Cons of Concrete Slab Houses
Slab foundations cost about $10,000 less than those with a basement or crawlspace. A lower foundation is more accessible for residents with limited mobility.
The footing is the part of the foundation that transfers the load to a larger soil area. It's the part of the foundation that is in actual contact with the soil. It makes the foundation safe for whatever settlement it's on. The materials used for footing usually consist of slabs or rebars.
Is it normal to have a crack in your basement foundation? Hairline cracks in a concrete foundation are common and may not be serious. These cracks often occur within the first couple of years as the concrete cures. However, cracks that are larger, diagonal, or actively growing warrant professional evaluation.
Some footings require no rebar, some do. Generally for typical loading, I run 2 #4 at bottom, just to span any problem areas, like if the excavator pulls out a boulder and replaces with uncompacted soil, that kind of thing. Most structural engineers will require more or less, depending on soil and loading.
The concrete is poured into a pre-dug trench, and the walls of a home are built upon it. When you're going to add a concrete slab on top of your footers, you want to make sure the slab doesn't move and that it has enough support to do its job.
Once the concrete has been finished (between 4-8 hours after pouring) and has set hard enough for walking on, the effects of rain should be minimal.
Poured concrete is the strongest type of foundation for a house. Concrete is incredibly strong and durable, and it can be poured into any shape. This makes it ideal for supporting the weight of a house.