Block and Beam

[Steted21]

All we are having an extension done taking the rear of the house from an L Shape to a box. The builder is laying a block and beam floor as the rest of the house has this too. Do the beams of the block and beam floor sit on the existing walls that are to be removed or does this also need a new footing dug? Obviously we have a new footing around the around the edge of the new walls which will then have courses laid and then the beams for the floor will come off these but am unsure how they will tie to the existing house?

Hope this makes sense

 

[noseall]

The beams will span on the new walls. They could be chopped into the existing walls provided said wall has the correct DPC detailing. Wide spans are frowned upon because of the trampolining effect and the fact you will need a crane or a machine to fit them.
Not sure what you mean when you say sit on walls to be removed (knock-through?). Have you not seen the drawings?
Need more info' please.

 

[garyo]

Why do builders use block and beam vs. traditional?

 

[noseall]

Why do builders use block and beam vs. traditional?

Crap over-site bearing strata.

 

[^woody^]

In 9 out of 10 instances is down to speed and ease of construction. For the other one, its because they had some left over from the last job.