The 440mm gaps left between the beams are then filled with standard size foundation blocks until the entire floor is one flat slab.
Concrete oversite floor.
The floor is made up of precast concrete beams shaped a bit like the rails on a train track.
At the time many ground floors of houses were formed as raised timber floors on oversite concrete with the space below the floor ventilated against.
So placed to prevent disturbance of the ground below to provide a relatively even and firm surface for the placement of the next layer and to keep out ground air and moisture.
In building terms the oversite refers to a layer of concrete that is used to seal the earth and create the ground floor of your house.
Like everything it is a very important step as it is what you will be essentially walking on when the extension is built.
Something that is left out missed or forgotten.
Oversite concrete is often reffered to as german floor by the laymen others mistook it for dpc however oversite concrete is the mass concrete that you pour to cover the entire lenght and breadth of a building on the ground floor to serve as a source of additional support to the structural stability of a building especially storey buildings.
These are laid on top of the inner leaf of the walls sitting on the dpc but with no mortar bed.