Standard Footing Size for 3 Story House

Footing consists of a column, pillar or wall at the bottom. The purpose of footings is to support the loads, moments and forces applied and the reactions produced, and to ensure that any settlement that may take place is as unvarying as possible and that the soil's safe bearing strength is not surpassed.

The effective crosssection in compression in sloped or stepped footings should be restricted by the area over the neutral line, and the angle of slope or depth and placement of steps should be such that the design requirements are met at each section.

The size of footing for multistoried building is solely based on several factors as follow :-

1. Bearing strength of soil
2. Numbers of the columns.
3. Entire dead and live loads.
4. Other loading and structural aspects.

The footing transfers the load into the soil. When the bearing strength of the soil is low, then the footing should be wider as required. If the soil is very strong, The footing isn't even required, if the soil is extremely strong as the soil underneath the wall would be sufficient to retain the building up.

Besides, the final reaction is directed to the column. It is based on different types of factors such as the type of construction like walls, occupancy type for live loads, dead load strength and most significant the beam length (spacing of columns).

If there is a load of 300KN/floor and SBC of 250KN/SqM , 2 metre by 2 metre footing is suitable. Normally 1.5m x1.5 m to 2.0mx2.0m is best suitable.

Also Read: Some useful construction tips for foundation design

It is found that heavy house on soft soil requires 2 feet wide or more footings. But, on the strong soil, the lightest buildings need footings as narrow as 7 or 8 inches. Underneath an 8-inch-thick wall, no footing is required.

In this regard, go through the following informative video tutorial to know the desired size of footing for 3 storied building.

To get more details, go through the following video tutorials.

Video Source: Civil Engineers