Most building may have series of columns or walls which are part of its structural system. These columns or walls will carry two types of loads - live load and static load. The loaded columns or walls may have high concentration of stress due to its small sectional area. This may result in a punch-through effect which would cause the building to fail or to collapse. To prevent this from happening, the installation of footing help to reduce the stress by spreading the loads over a larger area.
There are three main types of footings. They are intergrated footing with slab, isolated footing and strip footing.
Isolated footings are those individual pier blocks which sit into the ground. They are used to support walls, columns and post where load is significant within the area. The spacing of the footing depends on the load they are supporting - the heavier the load, the closer they are placed and vice versa.
Isolated footings are used along with strip footings in this construction. Each isolated footings are equally spaced so that the load rom the building can be equally distributed through all isolated footing.
Benefits, facts and situations best to be usedOnly a flat and compacted hole dug in the earth is required as site leveling is not a requirement. The depth will be governed by the earth structure.
MaterialsGenerally, all these materials can withstand moist, pressure, termite and fungal attack for a long time.
The size of the footing depends upon how heavy the load it is supporting. Generally, for reinforced concrete footings, it must be at least 150mm deep and must be at least 50mm wider all round than the column they are supporting.
Strip footing are footings than run in strips. They work much better that isolated footing as they can distribute stress applied from the load more efficiently.
Benefits, facts and situations best to be usedTrenches need to be dug, compacted and level to provide a firm and stable support. The depth of the trench depends on the type of earth structure within the area. The centers of footing placement is dependant of the load supported and is determined by the structural engineer.
Strip footing is used in this construction. Notice that they mainly run along the area where the wall are likely to be placed. This construction is more likely to use a slab with separate strip footing construction.
MaterialsAll materials used must be able to withstand moist, pressure, termite and fungal attack for a long time.