Why would you use a raft foundation?
A raft foundation is a reinforced concrete slab under the whole of a building or extension, ‘floating’ on the ground as a raft floats on water. This type of foundation spreads the load of the building over a larger area than other foundations, lowering the pressure on the ground.
What is the difference between raft and footing?
If we increase footing area the footings are overlapped each other, instead of providing each footing on each column all columns are placed in common footing. A raft foundation is a solid reinforced concrete slab covering entire area beneath the structure and supporting all the columns.
What is the minimum depth of raft foundation?
The minimum thickness of raft foundation is 300mm.
Do raft slabs have footings?
Depending on your property’s conditions, both waffle and raft slabs can provide a suitable footing for your new home.
What is the most expensive type of footing?
A basement is the most expensive foundation type, and unless you’re building a daylight basement—a basement built on a hillside that opens to the daylight on at least one side—this the space created by this type of foundation can feel cave-like, as it lacks natural light.
What is the difference between raft and mat foundation?
Usually, mat foundation is spread over the entire area of the structure it is supporting. Raft foundation is generally used to support structures like residential or commercial buildings where soil condition is poor, storage tanks, silos, foundations for heavy industrial equipment etc.
What is the difference between strip and raft foundations?
Strip foundation is used to support a line of loads such as load-bearing walls. … Raft foundation consists of a concrete slab which extends over the entire loaded area so that loads from entire structure are spread over a large area leading to a reduction of the stress of foundation soils is reduced.
Is a raft foundation expensive?
Raft foundations are relatively inexpensive and fast to put down, when compared with other types of foundation. Ground excavations are less onerous than for trench excavations, for example, and the foundation and floor slab can often be combined, giving significant savings on materials and time.