Please find attached a quotation for foundation sent to me by a contractor. i have excavated the land and some part you will see that its water logged. a lake is behind my land at igbogbo ikorodu.
Another contactor said i do not need iron rod for foundation since its a bungalow?
The recent flooding around has brought new challenges and raised questions on wether to use iron rods to support the german floor of a bungallow, especially in a seemingly solid soil or not.
Going by what I saw inspecting a 4 bedroom bungalow close to the Ipaja canal in Lagos state has reinforced my belief for a careful analysis of any buildings prone to flood in future.
In this case on a particular Sunday when there was much rain, the water overflew it’s banks and entered people’s houses. For the house in question it was originally raised high which was constructed by me for over 5 years now and there has never been any issue of concern until this prolonged rain and blocked drains that led to unusual flood . The soil itself is sandy and fairly okay stability wise, other buildings are also standing around but to save money as most will do which is very wrong, we raise d the blocks straight from foundation up to the roof without breaking it with german/oversite concrete at the foundation/dpc level, we only pour some volume of concrete after the building have been roofed without any iron rods or wire mesh to really sustain the compressive force of the concrete.
Now a problem was discovered after the flood incidence, there were visible cracks along the walls both laterally and vertically, suggesting that the walls might cave in anytime, there was also serious movements of the ground floor concrete depressing further down and leaving a thin line between the walls and the concrete at the edges of each room round. These happened because the concrete were poured separately on each room just to sustain the weight of the occupiers and we didn’t put into cognizance the pressure a flood in the near future may cause. Ordinarily a German floor with wire mesh/reinforcements or iron rods casted together at the dpc (foundation) level will have given us a well formed monolithic mass of concrete that will have served as a protection against water penetrating directly from the ground to the house.
The water that surrounded the building went to its foundation ,soften the sands underground, and when the water dried the next day the soil under the building was further compressed by the wetness, hence there was movement of the concrete in the rooms which made them to go down and thereby separating blocks from the concrete.
This problem could have been avoided if the German floor was done and the concrete was made to pass on top and round the entire stretch of the building block, however without reinforcements on the concrete with the situation at hand despite that is a bungalow , we would still have had the same experience.
So I recommend for a waterlogged area, or for a site very close to the water or prone to future flooding, it is better to go the extra mile and reinforce the oversite or german concrete with iron rods so that if there is a movement under the buildingthe foundation and the german concrete will be able to sustain the building.
However if you have encountered this problem already, don’t fret yourself, get a professional to suggest the best way the building can be reinforced and also protected against flooding.