What Is Grade on Slab?
Grade on the slab is a special type of slab which is constructed on the earth soil. This type of slab is constructed to support the walls and other structural elements. The construction of grade on slab is the place of ground level.
In grade on the slab, it does not need another type of foundation system because it itself acts as a foundation of the building.
Construction of Concrete Slab on Grade
There is some process that is followed to construct the slab on grade. The first step is to excavate the soil of a required depth. After that process, we need to compact the soil to reduce the air voids in the soil.
Then batters are placed to notify the corners of the slab and it acts as a mould of the concrete. After those above steps, a layer of gravel and bitumen is placed to increase the depth of the slab. It helps to reduce the entry of moisture and acts as a sub-base of the slab.
For reducing the cracking of the concrete, seven days of the curing process is done. In concrete slab on grade, the expansion joints are provided in the space between slab and wall.
Types of Grade on Slab
There are generally two types of concrete grades are presented, those are-
- Supported Slab on Grade: Supported grade on slab is selected where footing is already constructed and the ready to construct a column. Grade slab is basically rested on a gravel layer and it creates a moisture barrier. Here expansion joint is provided between wall and floor. Control joints are provided to resist the cracks in the slab.
- Monolithic Slab on Grade: This is a type of footing that does not have any type of footing. This slab acts as a footing and the columns & buildings are constructed from this. Here, batter boards are placed in that. Monolithic grad slabs rest on the gravel layers.
Advantages & Disadvantages of Grade on Slab Home
Advantages of Grade on Slab Home
There are so many advantages of grade on slab, those are-
- The main advantage of grade of the slab is that it’s inexpensive and sturdy because the whole structure of the building rests on the slab; there is no beam-column option.
- Another advantage is there’s no termite attack because the whole structure, which rests on the soil, is made of concrete, where no wooden material is used.
- For low-cost buildings, it is the best option to build this type of foundation.
- The advantage of the grade of the slab is that it’s widely used in the foundation of the garage, shed, etc.
- It is a low budget structure because the labour cost and the excavation of this are low.
Disadvantages of Grade on Slab Home
There are a few disadvantages are available for grade on slab, those are the following-
- The main disadvantage of this slab is that you can not access the bottom portion of this slab for cable lines or other purposes.
- The grade on slab is constructed on the ground and if the ground temperature rises then the room temperature is also rising. This is another disadvantage.
- The next disadvantage is if it’s constructed in a lower place where high chances of a flood, then it is very problematic.
- After sometimes slab foundation is also settled, then it creates so many problems and if some gas line or plumbing line is laid under the slab, then it is very problematic if it requires some maintenance.
Slab on Fill Vs Slab on Grade
Slab on Fill
Slab on Grade
|Another name for slab on fill is a concrete slab.||A slab on grade is basically known as a slab foundation.|
|It is made of concrete, gravel, stones, sand, etc.||It is made of bitumen and gravel.|
|It is placed on the aggregate layer.||It is constructed on the ground level.|
Slab on Grade Foundation Vs Crawl Space
Slab on Grade Foundation
|The building is built over the slab on a grade foundation.||Crawl space is the exterior support that is constructed to provide extra support to the internal walls and beams.|
|It is an inexpensive structure.||It is a little bit expensive structure.|
|It requires lesser time to construct.||It requires a slightly higher time to construct.|
|It is a more energy-efficient structure.||It is a less energy-efficient structure.|
|The grade on the slab is not applicable for flood-prone areas.||Crawl space has not like that type of limitations.|
|Grade on the slab is not accessible for cable lines, gas lines, plumbing lines, etc.||In craw space, you can access those.|