Do you know the material that’s commonly used as flooring in most homes or buildings? (as well as in roads?) Nope it isn’t wood (although floors made of wood definitely have that classic old-world feel), but it’s something called a concrete “slab”! According to one of my preferred concrete suppliers in town, a concrete slab is a popular structural material or element of modern homes and buildings, which consists of a flat, horizontal surface composed of cast concrete. Read on to find out how to lay slab correctly.
Site Preparation & Creating a Strong, Level Foundation
The first step in laying out concrete slab would be to ensure the site is properly assessed and prepared. As a slab is often several inches thick, and is supported by columns, beams, walls or ground. The site should also be prepared to ensure the strength of the foundation where the slab is laid.
If you’re laying slab on a patio, driveway or the house’s interior, you may require a permit from the local building department or council (depending on where you live). It’s also worth checking whether there are any pipes or water mains running beneath the area that you wish to concrete.
Your contractor will then position stakes on the areas where the slab will be laid, as well as use a line level and some string to determine how the ground slopes. In order to level the soil, the workers could dig into the higher side of the slope, add a retaining wall to hold the soil in place, or move soil into the lower end.
When laying slab, it would be best to know the soil in the area you wish to concrete, because if you’re building on clay or loam soil, you may need to make room for around 6-8 inches of compacted gravel to be inserted or placed under the concrete. If you’re building on sandy soil, what’s nice is that sandy soil does not increase the risk of the slab cracking due to fluctuating water in the surrounding surface.
After doing all the essential site preparation stuff, your construction team chooses the boards. In general, for garages and sheds, 2 x 12 boards with five inch thick slabs are used, while for driveways 2 x 6 boards are utilized.
To ensure a strong foundation, the contractors will also make sure that the base is able to effectively drain, because water that’s not absorbed can often lead to cracks and improper movement within the concrete slabs. If the area to be worked on has sandy soil, the contractors may need not add a layer of gravel due to the sandy soil’s absorptive properties.
Reinforcing Slabs with Steel Bars, Pouring the Concrete and Applying a Smooth Finish
The next step would be to reinforce the slabs with steel bars to prevent cracking, and make the site more durable. I’d generally recommend that you hire professional premixed concrete contractors to do the job, because this can be labor-intensive and will require a lot of technical or engineering experience. Well, you can choose to supply the bars, which can be bought at almost any home center or hardware store (along with the tie wires and wire twisting tools to connect the bars).
Before preparing the concrete truck, consider the weather conditions too, as concrete dries much faster when the sun is out in full force. So, fi your contractor is pouring concrete in hot weather, they might be better off dividing the slab down the middle and filling the halves on another day, thereby spreading the workload (and focusing on one slab at a time).
If the site preparations and other more tedious tasks are properly done, the concrete forms should be square, level and have the capacity to withstand the pouring of concrete. Again, the pouring of concrete should be done on days where it’s not too hot or too cold, to prevent fast hardening or thawing.
Once the concrete delivery truck arrives, the workers will pour concrete into the furthest forms so it will have time to set, and they won’t need to move the truck back and forth. The workers can also pour concrete on a wheelbarrow for hassle-free transportation. Once the concrete is poured on the surface, a float is used to remove any imperfections left by edging or easing the bumps from the bull float. To gain a smoother finish, workers can follow the float with something called “trowelling”, which smoothens out other imperfections (although this should be done by a professional).