A concrete slab is a flat, horizontal structural element that is a common and crucial part of modern construction. Generally, a concrete slab is around a few inches in thickness. It receives support from structures such as walls, beams, columns, or even the ground. It is used to build surfaces such as ceilings, floors, and roof decks.
Benefits of Concrete Slabs
Using concrete slabs offers the following benefits:
- Thermal comfort: Concrete slabs have a high thermal mass, enabling them to help in regulating indoor comfort by radiating or absorbing heat.
- Longevity: As long as its reinforcement is properly planned and installed and if the concrete is poured and compacted correctly, you can expect the concrete slab to last for a very long time.
- Termite resistance: Concrete slabs that are designed to have minimal shrinkage cracking are more resistant to termites.
Types of Concrete Slab
Below are some concrete slab types that are typically used in construction today:
This reinforced slab is easy to construct and does not require a lot of formwork. It is usually supported by caps or columns, without using beams.
This slab type is generally supported by columns and beams, which carry the load in its stead. Conventional slabs can be either one-way or two-way. In the former, the slab is supported by beams on two opposite sides, with the load being carried in one direction. In the latter, there are beams that support the slab on its four sides, meaning that the load is supported in two directions.
Hollow core ribbed slab:
This slab type features longitudinal cores or voids across the entire slab and is typically strengthened by a longitudinal rebar. These cores or voids serve to make the slab lighter, reduce how much concrete is needed, or as conduits for cables for utilities. This type is more commonly seen in multi-storey car parks or office buildings.
This type of slab gets its name from the shape it forms, with its square grids and deep sides. Waffle slabs are often used instead of conventional slabs to carry heavier loads.
Solid slab raft:
Serving as a form of shallow foundation, solid slab rafts are constructed using a reinforced slab that spans the entire footprint of a structure. It resembles a raft on water since it disperses the load to walls and columns along the area. This type is ideal for buildings that don’t carry heavy loads and are built on weak soil such as peat or clay.
This type of slab is created by pouring reinforced concrete on top of metal decking in order to create a composite structure.
How to Form a Concrete Slab
Concrete slabs can be constructed in-site or prefabricated. If you are going to construct a concrete slab on your building site, below is a basic guide teaching you how to form a concrete slab.
- Prepare the site: Before any construction work starts, make sure that you have the proper permits required by your local regulatory agency. Pouring concrete foundation properly requires a specific set of skills, so it’s always a good idea to work with an experienced and reliable company like ours to ensure professional-grade quality. Measure the lot line and drive four stakes into the ground to serve as rough indicators of the slab’s corners.
- Build forms: Make sure the ground is level and lay out boards for each side. Brace the form to make sure that the sides are straight. Nail them together. Remember that the concrete slab thickness will depend on the weight of the structure it will support.
- Build the base: When the forms are in place, spread and pack it with granular fill. Remember that the key to ensuring that the slab is crack-resistant is to have a strong base that drains well.
- Install rebar: To ensure the strength and resistance of the slab, install rebar.
- Pour the concrete: For small DIY projects such as sheds, you can try pouring a concrete slab with bags. However, if you are building larger structures, you need a concrete truck. Avoid pouring on hot, windy days since these accelerate the hardening process. Have someone add or remove concrete while you are pulling the screed.
- Float and trowel: Smooth the slab using a bull float. After the water bleeds out of the concrete and the slab starts to slightly harden, start hand floating and troweling for a smooth finish.
Cost of Concrete Slab
The cost of a concrete slab ranges from $4-8 per square foot. This means that if you are researching about how to pour a concrete slab for shed, expect to pay anywhere between $670-2,690 depending on the size of the shed you want to build.
The factors that influence concrete slab cost are the size and thickness of the slab and the use of any reinforcement like rebar or wire mesh. If you are looking for solutions, contact our company to find high-quality slabs designed to meet your specifications, budget, and schedule.