Underground soil pipe protection - new garage base

[studarude]

Hi all,

Ive got my garage base footings and floor dug out and ive exposed a 4" soil pipe that looks to be solely taking rainwater away from the house; i contemplated getting rid and re-jigging the guttering outlet to the rear of the house but it looks like it goes forward onto the drive and picks up another rainwater drainpipe so its not an option.

My question is such, what do i need to do above and below this exposed pipe to make sure it doesnt move or crack when the garage base is cast and the garage put up?

I'll get a picture as it'll make more sense! In short, the pipe is laying on the dirt at the right level, but the trench has obviously undermined its foundation, and im not sure what to do on top!

 

[pinenot]

When your building your underbuild, slip in a concrete lintel to bridge the drain pipe and pack the area around the pipe with small stones for movement...pinenot

 

[studarude]

Here is the offending trench:

So a lintel over the top of both areas of the pipe is enough? Layed up on top of the hardcore base i presume?

 

[studarude]

Anyone?

 

[freddiemercurystwin]

I detailed this on a project for someone a while back, I'll dig it out tonight if no one else butts in.

 

[freddiemercurystwin]

I lied, it was just a note:

Untitled

• freddiemercurystwin
• 8 Aug 2013
• 1

 

[pinenot]

Sorry, my internet connection has been down. This was how I was proposing it to be done View media item 64790 ...pinenot

 

[studarude]

the only issue is that i dont intend on casting a footing, i had intended to hardcore the trench (the ground has soft spots so want to ensure it doesnt move) and build up the middle with hard core leaving the same 'shape' as it is now, albeit 6" higher. That'll give me a 12" border of concrete base around the edges and be 6" in the middle.

So. My current thinking is to hardcore underneath the exposed areas of pipe, wrap it in 50mm thick lagging and build a hoop type frame from re-enforcing steel to go all round the pipe. Top it with DPM and fill upto and above with hardcore/sand then cast the base as normal.

Is that feasible? Over the top? Is there an easier way?

 

[studarude]

anymore for anymore?

How about if i created several 'hoops' from re-bar and drove them into the ground following the soil pipe till it exits, hardcore upto it and over it where the fall allows.

I figure a bit of DPM on the top to stop any seepage from the sand or concrete at the left hand side would do?

Your thoughts?

 

[dann09]

Why have you dug such a pit?

Have you consulted your neighbour?
Do you know where your neighbour's DPC is located?

The clay appears to drop at the bend - it should continuosly fall.
You must positively determine where your drainage, of any kind, runs and makes connections.

Any re-bar driven into the ground will rust out, possibly swelling and cracking its surround.

You might re-jig your guttering falls, and RWP's location(s) to eliminate the present RWP, and the clay drainage entirely.
Its a bad groundwork design anyway.

I would suggest coming back on here before filling the pit, and pouring a slab etc.
Do you have any kind of plan/drawing, and have you considered BCO?

 

[john4703]

Why not simply move it so it runs under the path and avoids the garage area?