HOW TO TAKE LEVEL
The builder is expected to carry his levelling instrument to site with an assistance along with
him to do the job. A reference point is taken in the building and is marked out, then measure
the height you wish to achieve from that point up. Now transfer the level or point to the four
corners of the building, when this is established, the carpenter will only need to throw one
line from one place to the other and he can begin to place the planks along the line. Some artesans will tell you that they can use plumb to get this level, this is not true, the best method is to use the levelling instrument. Measuring same distance directly from the ground floor to the top and doing same all over the building especially when its not a precast
structure, shows technical deficiency on the part of your builder, because most floor slabs are
not on same plane out of errors due to settling,lack of technical knowhow and carelessness from
the casters of the ground floor slab.
After the level is determined by the builder, next is for the carpenter to get ‘water level’ he will use this to transfer the level round the building. Water levelling instrument is an ordinary hollow transparent cylindrical rubber pipe that is filled with water and is easy to turn around the walls of the building. Remember water finds its level, the level of water at the end of the pipe in one place will be the same level at the other end of the pipe, so is easy for you
to transfer and determine the level round the building. After placing the planks supported by bamboo or iron rods under with other wooden materials like 2″ x 3″ wood, the iron bender is called to start fixing the iron rods on top.He must have prepared ‘concrete biscuit’ which is used to raise the iron rods to avoid contact with the wood, if not, by the time the plank is removed some parts of the iron rods will be exposed to air or moisture which will cause rusting and ultimately decay.The iron rods for the floor slab is run along, and the electrician is also expected to fix his pipes and sockets, likewise the plumber will also do some work if need be before you call the casters in to cast the concrete for you.
WHEN AND HOW TO CAST CONCRETE
Be prepared to rent a concrete mixer and labour for the casting especially when the area of
concrete is much. Mostly the concrete is in ratio 1:2:3 or 1:2:4 i.e one bag of cement to four headpans of sand,
and eight headpans of granite.Except for peculiar sites this ratio is ideal.
Inform the caster to bring a vibrating machine along, this is used when casting so that the concrete will settle properly and there will be less holes in the concrete.If you can get granites of smaller sizes like half inch to do the beams, it will be good for compactibility. The concrete will form well with finer smaller stones aggregates.As the concrete is been poured, follow the casters behind closely with vibrating machine and work on the concrete. make sure the beams are well vibrated at the joints especially because of the clusters of iron rods if not the concrete will not cover the beam properly.
Get a good mason that will spread the concrete round evenly with range and plumb for best result.Next day pour water on the concrete and blockwork can start on top that same day. By 21 days or three weeks the bamboo or cylindrical iron pipes support under can be removed, it must have fully set. Remove any cantilevered side after 4 weeks or a month.