I am of the opinion that building contractors and engineers spend too much money on bungalow foundation, especially in the DPC ( over site concrete).

My analysis here will be focusing on structural design and cost estimations of different bungalows foundation of different soil type such as dry, waterlogged, sandy etc. I will also be looking at the commonly used foundation typed for bungalows such as strip foundation, wide strip with reinforcement, pad footings, combined pad, continuous footings and extreme cases raft foundation for bungalows. will start by enumerating the steps that need to be followed why building a bungalows foundation from structural points of view and also considering cost.

1. Site clearance
2. transverse survey and the leveling of the site by a land survey or a civil engineer using either total station or theodolite
3. the setting out of the building
4. Excavation of foundation trenches
5. Foundation footings( popularly called blinding).
6. Setting of foundation if any in the case of pad footing, combine or continues foundation
7. setting of foundation wall or substructures wall.
8. filling of the foundation
9. preparation of the filled foundation for DPC by compaction
10. Formwork for DPC
11. Placement of oversite concrete on the prepared foundation.

I will start here explaining each of the steps listed below with simple arithmetic calculations of equilibrium, cost and with pictorial view of work done in the past.

What is site clearance: in a simple language, it is the removal of bushes, trees, and all other unwanted structures or material on site. materials such as site dump, unwanted sand or gravel etc. It also involved the removal of top vegetable soil of at least 150mm deep into the ground in other to allow for work to be done a solid surface.

How can site clearance be done:
There are two ways in which it can be done, namely;
1. Mechanical ways
2. Manually

1. mechanically: by using a grader to remove this unwanted site materials. This method is faster and cost effective over a large area of building land. I mostly recommend this type clearance for a big to medium project of 1 plot ( 50' x 100 or 15m x 30m) and above.
Most client are scared to use this method because of the perceived cost implication but in reality it offers more values for money because of the following advantages.

1. It offers wider coverage of work over a shot period of time.
2. It help to grade site uniformly, make access road to site and help to get rid of vegetable soil of 150mm above ground level.
3. Condemned soil from top soil removal can further be used to filled the foundation where laterite or other feeling materials are expensive.

Cost implication:
It cost about N60,000 - N80,000 to get a grader in Port harcourt
it cost about N30,000 - N 50,000 to get the vehicle that will bring it to site.
fuel cost of about N20,000
Total of = N110,000 ( minimun)
Total of = N 150,000 ( maximum)

2. manual method: This involve the used of crude implement like cutlass, hoe, rake and shovel to remove the bushes, unwanted materials and top vegetable soil of a building construction site.
This method is cost effective over a small area of land like half a plot for a 2 bedroom or 1 bedroom flat. It is cheaper and more labour intensive than the mechanical method. it is recommended for a small building project like a two bedroom or one bedroom flat on half a plot of land.
It cost about N20,000 or less to prepared a land for two bedroom flat bungalow using this method.

To be continued......