Constructing a concrete patio slab is just like pouring any other slab, only on a larger scale. Therefore, this project presents one major challenge that could impact the results: cracks in the concrete slab. Cracks that occur at the construction stage of the patio can be prevented by adopting proper measures during the project. With this in mind, here are four ways of preventing cracks in the slab of your newly constructed concrete patio.
Compact the slab base
The base refers to the surface on which you pour the concrete mix. One cause of cracks on a concrete slab is a loose base. If the ground isn't compacted, it offers no support to the slab sitting on it. Any form of movement underneath the base causes the concrete to crack. Therefore, before commencing the project, ensure you're working on a firm base. Use a ground compactor to compact the soil and create a sturdy surface for the concrete slab.
Wet the base before concrete pouring
A slab is constructed from a wet concrete mix. The mix has to remain moist during the process to ensure proper curing. Now, if you pour the mixture on a dry surface, the base will absorb the moisture, and this could cause the concrete to dry out before curing. Premature drying spells disaster for your concrete slab as it can lead to cracking. Wetting the base before pouring the mix prevents moisture transfer from the mixture to the ground. The water will prevent premature drying and protect the slab from cracking.
Mix the cement correctly
Proper mixing of the cement and aggregate has a significant impact on the outcome of the project. You can easily end up with a cracked slab even after using quality aggregate in your cement mix. Here, two factors come into play:
- Amount of water in the concrete mix
- Delays in concrete pouring
If you use too much water in the mix, it will weaken the concrete and cause cracking. This is because as the concrete hardens, it loses the excess water and shrinks. Shrinkage ultimately leads to cracking. Prevent this occurrence by lowering the water to cement ratio in the mix. Also, avoid any delays after mixing, and these cause premature curing. If you expect any hold-ups, use a plasticiser to create a high-strength, crack-resistant concrete mix.
Protect your patio slab from cracking by employing the above techniques. Note that while concrete pouring may seem like an easy DIY project, you need some level of expertise to achieve a durable structure that won't cave to the elements.
Contact a concrete contractor for professional construction of your concrete slabs.