Types of Concrete Foundations
Concrete is strong, relatively resilient, easy to mold when wet and is a cost effective raw material for building construction. In order to make a concrete slab, all you need is to prepare a wooden frame shaped in the same way as the shape you would want the concrete to take. You then excavate a hole for the foundation and place your frame inside the hole. Pour the concrete when still wet into this frame. The end result is a concrete slab. You can reinforce the slab with steel to make sure it is more robust and can withstand greater force or weight.
But even though concrete is very strong, it does have some weaknesses. In damp conditions such as prolonged wet weather, water may penetrate the concrete, causing it to crack. This means that one has to regularly check for any signs of damage to the concrete so that repair can be done immediately and cracks can be arrested before they become too large and pose a risk to building stability. When it comes to concrete foundations, there are a number of different types. But why is important for one to know what the different types are? First, it could save you both time and money in the short and long term. There are advantages and disadvantages to each and it all depends on how and where they are used.
The first type of concrete foundation is the T- Shaped concrete foundation. This is one of the most commonly used foundation types and is ideal when the goal is to support structures in areas where the ground is known to freeze. In ordinary circumstances, frozen ground exerts pressure on the foundation; but the T- Shaped foundation’s unique design enables it to resist any potential damage from frozen ground. You would usually place a section of flat footing below the expected frost line and then build the walls on top. The walls are not as wide as the footings thus providing that added level of support that is needed at building’s base. It is the inverted T shape of the final structure when viewed in cross section that the building gets its name. The T-shaped foundation is renowned not just for its resistance to the effects of freezing ground but also to its overall stability.
The second type of concrete foundation is the slab-on-grade foundation. Whilst this type of concrete foundation is also widely used, it is often used in areas where the ground does not freeze and thus there is no need for the T-shaped concrete foundation. In a slab-on-grade foundation, the slab is made as a single layer of several inch-thick concrete. You need to pour the slab thicker at the edges so as to provide a firmer foundation. You then use reinforcing rods to give extra strength to the thickened edge. In order to improve drainage, the slab should rest on a bed of crushed gravel. You can also embed a wire mesh into the concrete as this will reduce any chances of it cracking. Even though the slab-on-grade is ideally meant for places where the ground does not freeze, it can still be reinforced with insulation to prevent it from being affected by frost.
The third type of concrete foundation is the Frost Protected Shallow Foundation. As its name suggests, it is meant to counter the effects that would otherwise be caused by frost. This type of foundation has insulation placed on the outside of the foundation and utilizes heat loss from the building itself as well as the natural heat energy from the earth. A Frost Protected Shallow Foundation (FPSF) can be anywhere between twelve and sixteen inches below grade. This means that it can greatly reduce your costs of excavation, making it both a good preventative and economical alternative against damage from freezing. Whilst predominantly used in Scandinavian countries (there are over 1 million homes in Sweden, Finland and Norway with FPSF), there are about 5,000 buildings in the United States that have used FPSF successfully.
