Reducing a large / deep inspection chamber for vehicle traffic

[VWP]

Hi All

I have a 5 ft deep brick inspection chamber on my drive.

Its 1.2m x 800 ish

I am going to reduce it by spanning the 800 width with one of the below options
1 - several 6x4 concrete lintels
2 - several small steel RSJ's
3 - shutter it, add rebar and pour an 8 inch deep slab
4 - 10 mm steel road plate

This will see vehicle traffic as its on my drive

anyone got any recommendations?
anyone done it
i cant find a reducing slab thats not a fortune

cheers folks

 

[Hugh Jaleak]

Does the chamber just take the waste from your house? I'd hazard a guess though, given the size, it's a shared (public) sewer.

If the chamber is on a shared sewer then it's the Water Co's asset, you'll need their permission, carry out the work to their specification, and you possibly may need to use one of their Approved Contractor to make any alterations to it.

 

[JohnD]

what sort of vehicles will be driving on it?

What is the existing lid?

Photos inside and out will help.

 

[VWP]

Just takes our waste
no idea why its so deep.
house is 1910.

had a ( broken ) sandstone flag over one half and a cast lid on the other
will have my t5 vw van on it

will be getting block paved and a recessed block paved lid on once reduced

 

[Hugh Jaleak]

Traditional method was to corbel the brickwork, later methods were to cast an in situ slab on top of 9" engineering brickwork. I'd go for the concrete slab, it should last longer than steel in that environment.