block and beam floor question

[scaffers]

hi all

im doing an extension, struggling thru

the extension sorta wraps the rear of the house being 3m deep one end and 4.5m deep the other and 10m long. all planning granted etc

in the plans the architect has allowed for a block and beam floor all along the part that 3m deep x 6.5m long spanning from the house to the new rear wall, where the extension is slightly wider at 4.5m deep by 3.5m wide he has the block and beam running the 3.5m way {90degrees to the 3m block and beam} with a sleeper foundation picking up the block and beam floor. the problem here is the sleeper foundation crosses the existing manhole / drain access. if i lose the manhole/drain we wont have any services in the house till a new one is dug.

do you think if i speak to building control i can run the block and beam in the 4.5m direction and do away with the sleeper foundations. its only a domestic ground floor extension so i dont think the loadings will be greater than what the 4.5m beam will take ?

thoughts / advice pls



scaff

 

[Leofric]

Discuss it with the architect first and let him/her amend the drawings as necessary.

 

[^woody^]

The floor beam manutacturer will be the only one who can tell you in which direction it needs to go.

But I can't see why you would not want to sort out the manhole before putting the floor in.

 

[Notch7]

I would discuss the options with your builder and then the block n beam manufacturer -and explain what you want.

you need to dig down next to the house -you cant assume the house brickwork and or foundation will be ok for block n beam -I mean you may have a fairly modern house so may be ok, but dont assume pockets in the house wall will be ok.

this link gives you a bit of an idea on the beam specs
standard beams can give a maximum span of up to 5.8M depending on the design......although a 6 metre beam weighs about 200kg

https://www.supremeconcrete.co.uk/products/structural-products/floor-beams/standard-beam

 

[Leofric]

Procedure ideally , architect - block and beam manufacturer /structural engineer - building control - builder. The architect should now take account of the manhole and the block and beam company will design the beams as required. They actually design every beam with reinforcement to suit the span and loadings.
Of course it depends who is actually dealing with the block and beam manufacturer and whether the work is being done under a Full Plans Submission or a Building Notice.

 

[noseall]

if i lose the manhole/drain we wont have any services in the house till a new one is dug.

Why not dig the new one? It may be possible to temporarily run the 110mm soil pipes across the site and into the new IC. These could be removed and reinstated on a daily basis whilst the foundations are being completed. We have done some inventive things regards temporary works.

 

[scaffers]

cheers guys

just to add, the new drains will be outside of the foundations, so we cant dig them yet

 

[scaffers]

Just an update

Architect was little help. I spoke to the building inspector and he agreed to changing the direction of the beams and missing out the sleepers

Full steam ahead