Concrete slab foundations are commonly used in modern buildings and homes in the Southern U.S. They are generally cheap and easy to install. However, homes with this type of foundation have no crawl space or basement.
Aside from building foundations, slabs have many other uses. Thick slabs are used in ceiling and floor construction. Leaner paving slabs make perfect exterior paving materials. They are suspended between steel frames from ceilings and floors. The leaner ones also make the perfect patio and improve the aesthetics of a building.
Here, we will define what a slab foundation is, how it’s built, and look at its pros and cons.
What Is a Slab Foundation?
A slab foundation is formed by concrete and reinforced with steel rods. It’s laid over soil-based areas and typically measures four to eight inches thick with thicker edges to add strength to the perimeter. A slab is monolithic, as the concrete is poured all at one time.
Once the foundation slab cures, the home is built right on top of it. This type of foundation is suitable for homes in warm climates like Florida’s.
How to Build a Slab Foundation
Slab foundations are easy to build as they require little preparation before beginning the work.
- Determine the width of the foundation. This depends on the structure’s design and ground conditions. Ideally, the foundation should have the same dimensions as the home or building you’re constructing.
- Prepare the ground by removing objects and impediments such as sticks, rocks, and roots from the ground.
- Next, frame the slab area using inch boards. Pre-made 2 by 12-inch boards will make the work easier.
- Level the ground with a rake so it’s completely flat.
- Dig footings along the inside of the form, roughly three feet from the perimeter.
- Compact the soil using a tamper. Slamming the soil over and over brings the dirt close together.
- Push stakes of rebar into the footing trenches and tie them, ensuring they cover the entire area.
- Mix sand and mortar then pour it into the footers. Ensure it covers the whole of the foundation’s perimeter. Leave it to dry.
- Enclose the entire perimeter with wooden boards to lay the foundation. These will hold the concrete that you will pour.
Builders use post-tension cables and steel rods to make the slabs sturdy and capable of bearing the structure’s weight. The slab is also placed in a layer of sand to act as a cushion and to improve drainage conditions.
During construction, slab foundations need to be built on grade soil so they won’t shrink or settle.
Benefits of a Slab Foundation
Some of the benefits of using a slab-on-grade include:
Economical: A slab foundation is cheap both in terms of labor and material use. This explains why houses built on slab foundations are affordable. They also require little maintenance.
Easy to construct: Another benefit of creating a slab foundation is that it takes a short time to build. No excavation work is required. The builder uses poured concrete, which takes a few days to cure. They won’t halt the construction work to wait for the foundation to cure, hence no delays.
Reduced Mold Growth and Pest Interest: With slab foundation, you won’t have to worry about mold and rodents as much as you would with other foundations. Slab-on-grade homes don’t have the same openings or space underneath that might allow mold growth or rodents to be interested in the home.
Easy to extend: If you need to expand your house in the future, it will be easy with a slab foundation. They are easy to extend and cheap. Just consult your contractor, and they’ll know what to do.
Durable: Slab foundations can last for more than 100 years provided they were quality built during home construction.
Easy to decorate: It’s possible to stain and texture the materials for aesthetic purposes.
Cons of Slab Foundation
On the downside, slab foundations tend to crack with time. The cause could be anything from soil displacement, frozen ground, earthquakes, and tree roots. These cracks can compromise the structural integrity of the building. Slab foundations also don’t offer sufficient protection to homes in stormy weather.
If you’re more concerned about building costs and below-grade space isn’t a top priority, the slab foundation is a fantastic choice for you. Be sure to take the necessary precaution to keep it moisture-free.
Would you like to protect your slab foundation or carry out exterior waterproofing? Contact JES Foundation Repair for a free waterproofing inspection and quote. Our experts will assess the foundation and recommend solutions that’ll keep it dry and trouble-free for years to come.