The slab foundation or also known as plate foundation or foundation plates, are characterized by being superficial foundations that are conditioned in platforms, its main objective is to transmit the loads from the structure to the ground, distributing the forces evenly.
These have a main reinforcement in their upper part in order to counteract the counter pressure of the ground and the thrust of the groundwater, it also has a lower reinforcement, exactly under the pillars and bearing walls, which is responsible for excluding the productions of the uneven arrows as far as you can. In the case where there is terrain with little resistance or with a very poor load-bearing level, that is, below 1 kg / cm2, it may happen that the footings found on the isolated pillars come together.
Slab Foundation Pros and Cons
slab foundations have many advantages to carry out a project, but at the same time they can also have certain disadvantages. Next, we are going to tell you in more detail each of the advantages and disadvantages.
Pros of the slab slab foundation
- One of its great advantages is that this type of foundation is generally less expensive, compared to others, to build foundations and piers.
- Another advantage that a slab foundation offers you has to do with the construction time, this is because it does not take much time to build them. Usually the slab is built in one day. Of course, there must be prior preparation work. In other words, the complete production process can take about four days, from its beginning to its end, making it clear that we do not include problems that may exist with the weather.
- Mold, rodents and insects are not a problem. Thanks to the fact that the slab foundation does not have a space under it, it prevents mold from forming and rodents from nesting in it.
- With this foundation, you can have more flooring options, including marked or stained concrete.
Cons of a slab foundation
- Not having an access space underneath it means that utility equipment cannot be located or hidden there. Thanks to this, many ducts can be installed inside the walls or in the attic.
- Because the pipe that a structure has is located under the concrete slab, if there is any type of leak it is necessary that the repairs be made using a hammer to break the slab and repair the leak. This procedure can certainly be very messy, and the procedure is also very expensive. Because leaks in pipes are under the slab foundation, safely detecting them is a difficult task that starts with very expensive bills.
- Cracks can become a problem, this is because the slab is made of concrete. It is of great importance that you learn why a slab foundation can crack. Despite the fact that concrete is a very strong material, it is prone to cracking thanks to the variation that can exist in climate and humidity. We advise you to water sparingly around the foundation in order to maintain the proper and constant humidity level.
This is all you need to know if you are thinking of using a slab foundation in your project, keep in mind when it is appropriate to use it, the design, its thickness, the structure, its regulations and the different types of slab foundation that you can use without neglecting the advantages and disadvantages that it can offer you.
When is it good to use the slab foundation?
slab foundations present several moments in which their use is appropriate, below, we will explain what those moments are so that you take them into account when using some type of foundation.
- At the moment the construction has a small surface compared to the volume such as warehouses, silos and skyscrapers.
- When the base of the foundation that was calculated is such that the transmission of the load at 45º is undoubtedly an excess depth.
- At the time the terrain had uneven stratification and uneven settlements were predictable.
- When the ground has a great thickness and a loose seat and the piles to be used would have a very exaggerated length.
This is the design of a slab foundation
The slab foundations can have a continuous design, with the same thickness, of constant section, it can also be designed with a thinner shape that has reinforcements in the supports of the pillars, using inverted mushroom-shaped capitals for this; Thanks to this, the denomination of fungi forms arises. On other occasions they can also be transverse and longitudinal beams that are responsible for linking the bearing supports that support thinner slabs.
Minimum thickness of slab foundation
Slab foundations must have a minimum depth of 30 cm. on a clean base or poor concrete. Although in general the slab foundations have edges that range from 50 to 120 cm, that depends on the type of building they intend to support.
Slab Foundation Structure
This type of foundation is built in reinforced concrete that is prepared in order to reduce possible settlements. The slab foundations have an optimal response in soils that have substantially homogeneous strata and at the moment that the building distributes the efforts on the slab with a grid that is responsible for keeping the geometric symmetry.
Slab foundations are also chosen when it is necessary to build a dry basement in a work that is located on land that has a water table. This alternative can be given through the layout in a board or foundation platform that is responsible for transmitting the loads of the building to the ground through a surface greater than or equal to that of the work.
To achieve maximum rigidity with minimum material consumption, proceeding as is generally done in the forging of hollow pieces; This is done by wrapping a whole system of filler or hollow pieces in concrete.
Regulations and types of slab foundations
The regulations governing slab foundations are the NTE-CSL. On the other hand, the different types of slab foundation that we can find are slabs with capital, slabs of constant thickness and ribbed slabs.