Builders in Ngong widely use the beam and block system for residential construction, especially in areas where black cotton soil covers 90% of the land.
This soil type drives up excavation and backfilling costs to create a stable foundation. Many builders find this process costly and time-consuming, yet traditional slabs that rest entirely on the ground make it unavoidable.
However, the beam and block slab offers a more efficient alternative. Builders excavate only trench foundations for walls before securely suspending the slab on the ground beam. This method significantly cuts excavation, backfilling, and formwork costs, especially as steel and construction material prices continue to fluctuate.
About the project
This project features a residential house in the interior of Ngong Town, Kajiado County. Built on half an acre, the home spans approximately 300m² across the ground and upper floors. It includes four ensuite bedrooms, a fitted kitchen, a TV entertainment room, and an extended foyer connecting to the rest of the house.
Builders began construction in early February 2023 and expect to complete it by the end of September 2023.
Clients dilemma
Ngong being an area with predominantly expansive soil, the contractor aimed to use a solution that would circumvent the tedious and expensive process of excavation and backfilling to achieve stable ground for the residential house.
Site visit
Solution by Ecoconcrete
Builders avoided mass excavation, eliminating the need for backfilling. Instead, they excavated only the trench foundation and securely suspended the beam and block slab on the ground beam.
Conclusion
Building on black cotton soil is made easier with the beam and block-suspended precast slab.
- No mass excavation and backfilling
- Quality product as it is factory produced.
- It conforms to international standards.
- Fire/sound resistant.
- Fast and easy to install.
- Use of minimal unskilled labor.