What is a raft foundation used for?
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.
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.
Where is raft foundation applicable?
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.
How does a raft slab work?
Raft slabs consist of a thick steel reinforced slab that is integrated with steel reinforced beams, which are dug into the ground for added strength and support. … It’s also more suited to sloping blocks as the edge beams are dug into the ground and working the slab into the soil and slope.