Digging a 2.5. Meter hole for a soak away

[Grasie]

Hi all

I am extending my property and as such need to dig a new soak away. The only position for this is on ground 1 meter higher then the planned building site and as such have been told I need to dif down 2.5 meters.

This is not a problems such and I am already 1.5 meters down but I am now concerned about the trench collapsing and need to know the best way to shore this up.

I was planning on using 12mm nor board on each side with supporting struts running across the pit. Is this going to be enough to secure my safety whilst completing the work?

Has anyone got previous experience of this they an pass on?

Thanks.

 

[tim00]

Dont even try to do what you propose. There are regs ref trenching and shoring. Take local professional help. I know of two instances where pipelayers were buried in trenches of 1m deep - in wet ground.

 

[Norcon]

I know of one where the bank caved in on a guy and buried him.
The digger driver was sat watching it from his cab seat.
He dropped the bucket into the soil and dug him out in one scoop ripping the shirt of his back.
He was a wreck after that incident and sold his digger as his nerves got the better of him.

Is this a manhole your constructing?
The way we do these is build the peri shuttering above ground which will be 1.2m x1.2m in size.
Then excavate a large hole to suit. Sloping it back to what ever makes it safe.
Then suspend the shutter in the hole with strong backs and pour concrete around. Any pipework being fixed before the pour.
Then a concrete biscuit lid on top pre cast on site and a 10 ton manhole lid. Job done.
Only time we lift blocks is to peg them into the pour if were a bit short on concrete.

 

[noseall]

Use a mechanical digger.

No need for shoring.

Have the back fill ready or the crates.

Give B.C. a ring in the morning, have them look at the hole then fill it with soakaway material.

Fill to within the drain inlet then stop worrying.

Were you seriously thinking about digging a 2.5m hole by hand?

 

[Sophie83]

you can hire trench sheets and shoring props from Mabey hire. if you phone them and tell them what you are doing they can recommend a suitable system with instructions.

 

[Grasie]

Thanks for all your replies, negative and positive. I have completed the digging by hand without incident and shored the pit using OSb and timber battens.

Now have to do a soil infiltration test for the building control officer to see if I need to use crates or can use hardcore.

I'll keep you updated.