Most footings in Australia are concrete. Concrete is a strong and versatile material that is usually reinforced with steel. There are many different types of footings so when designing your new home or extension it is important to seek the advice of an engineer.
All concrete footings will need some kind of steel reinforcement ("reo") This will need to be specified by an engineer and installed precisely to their instructions. It is probably best to let a professional concreting team install the steel as it must be inspected by council, and there is little room for error.
Types of footings
These are the most common types of footings for masonry houses, as the name suggests they are a "strip" of concrete which run under the walls of the house.
Strip footings may need to step up or down to accommodate for slight slopes or change in ground condition. This means the reinforcement will also need to step.
The dimensions of the footing will vary but will be from approximately 400mm to 600mm deep and wide, following the length of the wall. This may help you to estimate how much concrete you will need for your costing schedule.
Pier and Beam Footings
If the site has extremely deep soil above the rock or solid ground then it is most likely that pier and beam footings will be needed. The piers will be drilled down by the excavator until they touch the rock, the concrete is then poured into the tall cylindrical hole until the level of the bottom of the footing, which are essentially the same as a strip footing.
Most timber houses and any houses raised above ground (such as queenslanders) will utilise pad footings. These will also need to be designed by an engineer. Each pad of concrete will support some post either timber, block, concrete or brick above the ground to form the base supports for the house.