Building a house yourself is easier than most people think, albeit time consuming, if you decide to supervise construction yourself and forego the architect or construction contractor, you will save money, acquire a couple of management skills and experience that can be translated to other areas of your life or expertise.
The first things you’ll need are land, money (no brainer) and a building plan. If you decide to bypass an architect, getting a great building plan is entirely up to you. Next you’ll need to get your building plan approved by appropriate authorities, this will be the FCDA if your location is Abuja. Consider yourself lucky if you get a building plan that wasn’t designed by an architect approved.
Now you’ll need to clear the site from boulders, ant hills, shrubs, trees or anything that may interfere with your building, you will also need to clear the loose top layer of soil and organic material, once your site has been cleared you can start setting out the building, setting out can be done using wooden pegs and ropes to map out lines along which the foundation will be excavated and your load beating walls will sit, this is assuming your house will be constructed using concrete blocks and mortar which is the common method of construction in Nigeria.
During setting out please ensure the exterior walls of your building is not positioned too close to your fence, maintain at least 1.5m off set from the fence on the sides and have enough ample car parking space, the guys at FCDA or your local building regulation authority will ensure you adhere to these zoning codes before approving your building plan anyway.
Before you go looking for construction workers I suggest you invest in fencing your site (if it isn’t already fenced) with barb wire or a brick wall and have a secure storage room (can be an old shipping container or small hut) to keep your wheel barrows, shovels, trowels, bags of cement, horse bench, plumbs and other construction equipment safe. Also ensure you have a borehole, a water storage tank, a well or astray supply of potable water. When this is all sorted out you can call in the first set of construction workers to begin excavation.
You want to start excavating your sewage disposal pit first, it is commonly known as soak away, this is done in order to provide you with a ready supply of laterite when it’s time to backfill your foundation. The sewage excavation may vary from 4-6m in depth depending on the size of occupants you plan to design for.
Your foundation’s excavation depends on the load bearing capacity of the soil, if the ground is hard enough and not swampy like most sites in central and northern Nigeria then a strip foundation excavated to at least 2.5 meters will be okay.
Excavation is done along the lines you set out earlier, after excavation is complete you need to level the floor below with a layer of concrete to ensure it is flat enough for your your foundation blocks to be built on, the soil below this layer of concrete must be well compacted. A typical concrete mix for your foundation works consists of cement, fine sharp sand, gravels and water. This procedure is called blinding, give the blinding a day or two to cure (solidify).
The masons (brick layers) can come in now to start laying the foundation blocks of your new building, these are usually hollow concrete blocks so each hollow has to be filled with concrete to provide extra strength. A plumber has to be on site during this stage to install your sewage disposal and water supply lines. It is important to check that the bricks are being layered perfectly horizontal and straight.
When the foundation walls have been built use rock boulders referred to as hard core to fill in the spaces between the rooms, these rock boulders are what the floor of your house will rest on, then fill the spaces in between these boulders with smaller gravels and finally use the laterite you excavated from the foundation and your soak away pit to fill in any extra spaces and ensure it is properly compacted.
Now it’s time to spread a layer of water resistant material over the whole foundation before casting your floor slab, this is done in order to prevent moisture from the soil rising up your walls and damaging your building, the technical term for this procedure is damp-proofing and it is very important. A layer of polyethylene called a damp proof membrane is spread across the compacted hard-core before a another 150mm thick layer of concrete is poured in to form your floor slab, you will need a carpenter and some wood at this stage and depending on the surface area of your foundation you will need a concrete mixer to ensure consistency of the concrete mix. It is best practice to introduce a steel wire mesh into your concrete floor slab to prevent cracks in the future. Also remember to contact an iron bender, while the foundation excavation is on going, they will help you cut, place and bind the iron rods which provide structural support for your walls and columns.
To be continued…