A concrete pit is a durable, below-ground structure made of concrete that is designed to provide a functional space for various applications. It typically consists of a square or rectangular shape, open at the top, and can vary in size depending on its purpose. Concrete pits are commonly used in industrial, commercial, and residential settings, offering a reliable solution for managing utility lines, water drainage, or accessing underground infrastructure.

Constructing a concrete pit involves several essential steps to ensure its stability and longevity. Here's a simplified breakdown of the process:

Excavation

Start by digging a hole in the desired location and ensuring it's large enough to accommodate the pit's dimensions and any necessary clearances.

Reinforcement

Install a sturdy framework of steel rebar or wire mesh within the pit to ensure its strength and durability.

Formwork

You can implement pit boxes around the excavation site to define the shape of the pit. These pit boxes act as a mould for the concrete.

Pouring the concrete

With the pit boxes in place, carefully pour the concrete mixture into the pit, ensuring it is evenly distributed and adequately compacted to eliminate air pockets.

Curing and finishing

Allow the concrete to cure over time, following the manufacturer's recommendations. Once cured, remove the pit boxes and finish the surface as desired, such as smoothing or adding protective coatings.

While it may be tempting to pour concrete directly onto dirt when installing a concrete pit, it's not recommended. Concrete needs a stable base to prevent cracking, settling, or other structural issues. Without proper preparation, the soil beneath the concrete can shift, leading to uneven surfaces and potential damage over time.

To ensure a solid foundation, it's crucial to prepare the ground properly. This typically involves excavating the soil, compacting it to eliminate air gaps, and adding a layer of compacted gravel or crushed stone. This stable sub-base provides a solid surface for the concrete, promoting even weight distribution and minimising the risk of future issues.

Yes, pouring concrete against an existing concrete surface is possible and commonly done when constructing concrete pits. This method allows for seamless integration between the new concrete and the existing structure, providing a continuous and sturdy foundation. 

When pouring concrete against concrete, it's important to ensure proper surface preparation. Clean the existing concrete thoroughly, removing any debris, loose particles, or contaminants. Additionally, consider applying a bonding agent or primer to promote adhesion between the old and new concrete surfaces.