When you plan to lay a concrete slab, it is important to also have a layer of gravel underneath. When gravel is on the ground, the foundation is solid and the concrete can be compact. The gravel can also supply the foundation with a great amount of drainage that will keep water away from the foundation and out of the concrete.
It may be argued that a clay soil is also able to offer a nice alternative to gravel, but the problem lies with the amount of drainage. This clay soil will not allow proper drainage and will cause the concrete slab to crack or sink.
Below, we explain why it is important to use both concrete and gravel with your foundation.
The Reason For Using Gravel Underneath Concrete
Also known as crushed stone, gravel is able to provide a concrete surface with stability. Soil that is compact and solid can easily shift as soon as there is a change in the weather, which may result in cracks to form.
You should know that gravel is made from an array of material and comes in different sizes. These sizes are dependent on what the gravel will be used for.
You Can Compact Gravel
When you compact gravel, it provides benefits such as keeping a surface level. When the surface is level, you will have an idea on the amount of concrete you will need to pour. However, the benefit that matters the most is allowing drainage. When water soaks underneath the concrete, the soil can erode, by keeping the gravel compacted, it is able to prevent this erosion.
Gravel can also create a barrier for moisture. As water hits the concrete, it will attempt to penetrate the capillaries in the concrete. The gravel will prevent the water from entering the capillaries. When used, the gravel creates large spaces that prevent water from traveling through the concrete and reaching the surface.
With gravel having great properties for drainage and stability, it becomes a great concrete base. The gravel also eliminates an excess amount of concrete. When a surface with gravel is level, the amount of concrete required can be easily calculated. If the concrete is poured directly on the soil, you need to consider the terrain and if it rises or dips, which may require the need for more concrete.
Which Gravel To Consider
The best gravel that you should consider is known as washed and screened, which is ¾” to 1”. This is used a lot in driveways and can be packed quite easily as long as it is no more than 1”. Plus, you may have difficulty in leveling the larger size gravel. This may make it difficult to determine the amount of needed concrete.
Summing It Up
When a slab of concrete is poured, it can be a lot of work and can take a lot of time. However, if you want it to last, then the work should not be easy. You should also consider using gravel as well so that it can easily support the concrete. If you are planning to lay your foundation using gravel and concrete, then you should get a hold of us now so that we can guide you throughout the process. That way, your foundation will remain level and solid.
