In the construction of a building, the most important part is the foundation and one of these foundations are called footing, because it bears the full load of the building. But there are many types of foundation that we have considered and used—which depends on the strata below the building or structure. A civil engineer should thoroughly inspect the footing before it can be poured with concrete.
Soil investigation is a great help in deciding what type of foundation a building needs, and it will be shown in the recommendation of the engineer from an approved third-party laboratory.
But mostly, isolated footings are commonly used in a building’s construction. Our article today will explain how to inspect a footing and to be approved by the engineer prior to pouring concrete.
1. Ensure approval of drawings
The engineers shall ensure that the drawings for the footing foundation shall be approved by the consultant before conducting an inspection. This is to make sure that the installation of forms and steel bars are correct as per the approved drawing. Rework due to nonconformance can then also be avoided. Non-conformance could otherwise result in an increase of construction expenses due to rework.
2. Check the reinforcement
Reinforcement plays a vital role in the construction of the foundation as it strengthens the concrete foundation. Bear in mind that the foundation is the element of the building that carries the structure, and it must maintain the integrity of the building.
3. Concrete covers
A concrete cover is the important part of the concrete elements, especially in a foundation. Because of its location below the ground, it is common within the water table and the foundation is therefore prone to water penetration. The concrete cover usually ranges from 60mm to 75mm for a footing. Therefore, it is vital to ensure its required concrete cover.
4. Dimensions of the footing
The inspector should also see to it that the footing size and dimensions are followed as per the drawing. The engineer should check the thickness, width, and length.
5. Starter bars, steel chairs, and ties
The inspector should make sure that the starter bars are installed as per the approved shop drawing. The same with the steel chairs, which should be spaced as per the drawing. All steel reinforcements should be tied with 16mm diameter tie wire, approved via material submittal.
6. Cleaning and removal of unnecessary materials
The engineer should also ensure the cleanliness of the bottom of the footing and the removal of all unnecessary materials. There are many waste materials during the construction of a footing, such as wooden cut pieces, tie wires, sawdust, and plastic—these can cause honeycombs and increase the chance of the concrete being permeable.
7. Approval of the municipality engineer
Before the pouring of concrete commences, the foundation should be inspected by the municipality by their representative inspectors. No pouring of concrete should be done without their approval.
The contractor is duly appointed by the client. The engineer shall make sure that the footing is properly constructed via approved drawings, and it shall be based on his good judgment. The municipality engineer shall proceed with the inspection if it is approved by the engineer who supervises the project.
If the project applies a standard procedure, as laid out above, for the construction of the foundation, it will ensure the soundness of the work and avoid the collapsing of some part of the structure or concrete elements, ensuring that such accidents can also be avoided.