Soil pipe foundations in the way - quick answer needed

[thomp1983]

Hi,

I need to install my new soil pipes but the foundations are in the way.

In the above picture my ic base is under the piece of board, the outlet with the bigger spirit level will be a vertical soil pipe up the side of the house, the smaller spirit level is the downstairs toilet.

As you can see above I can't get the pipes against the brickwork due to the foundations, building inspector has said I can't have bends in the wet part of the pipework so I need it to go through the foundation.

I'm proposing to cut the foundation out between the 2 levels in that second picture, install my 110mm pipes inside some 160mm pipe to the rest bends then shutter the side of the trench and refill with concrete.

Will the above work and will removing that 2ft section of foundation weaken the extension? I need to know quickly so I can get on and get it filled in

Thanks
Chris

 

[noseall]

Just smash any of the toe out of the way. Don't put concrete back either

 

[thomp1983]

Thanks, I not long ago spoke to a builder I know in passing and he said the same thing, just make sure I don't dig across under the block as best as possible (undermining?)

 

[Hugh Jaleak]

Really fail to see what harm 2 slow bends would do to dogleg around the footing, but some BCO's can be very anal on things.

Did a deep drainage job a few years back, absolute nightmare as we were trenching through solid bedrock, dropping 375mm concrete pipes in, (eventually). Progress was slow but steady, Clerk of Works goes on his holidays, his replacement turns up and wants a clear gap between the collar of the pipe and the rock, so more work breaking out a slot in the bottom of the trench to accommodate this extra width....

 

[Dereekoo]

Really fail to see what harm 2 slow bends would do to dogleg around the footing, but some BCO's can be very anal on things.

Did a deep drainage job a few years back, absolute nightmare as we were trenching through solid bedrock, dropping 375mm concrete pipes in, (eventually). Progress was slow but steady, Clerk of Works goes on his holidays, his replacement turns up and wants a clear gap between the collar of the pipe and the rock, so more work breaking out a slot in the bottom of the trench to accommodate this extra width....

Can't fault his logic otherwise you would have been supporting a concrete pipe at each end and asking it to act as a simply supported beam to take the soil loads. If it had a pea gravel bed the effect would have been mitigated but not completely.

 

[Hugh Jaleak]

Can't fault his logic otherwise you would have been supporting a concrete pipe at each end and asking it to act as a simply supported beam to take the soil loads. If it had a pea gravel bed the effect would have been mitigated but not completely.

All pipes were laid on a peagravel bed, had to be to allow the Pipelayer to get the require position to achieve the correct fall.

I didn't word it very well, should have said more work for the Pipelayers, as it had to be done with a Jackhammer. He wanted the gap between the sides of the trench and the collars, difficult to break out accurately with a machine mounted breaker at 5 metres down.

My point was that his colleague was happy with the work, he arrived on site and wanted things done differently, so it's down to personal preference rather than the Regs.

 

[thomp1983]

Today's seen me spend 6 hours with the kango smashing the foundations out, soil pipe that will receive waste from upstairs is in and perfectly level.

The inlet next to the new pipe will receive the soil pipe from the downstairs bathroom, can I get away with using an angled connector into the inspection chamber and an angled connector at about the level of the trench block this will mean I only need to remove about a foot more of foundation to get the pipework in, if not I've another metre deep's worth to break out.

Would you concrete the rest bends in place or just fill with pea gravel then backfill?

Thanks
Chris

 

[noseall]

Concrete the IC base. Leave the rest for pea gravel.

 

[thomp1983]

Well I decided to go with an angled pipe.

Used a 90 degree with rodding access to receive the toilet waste pipe through the wall, this was followed with a 300mm vertical piece of pipe, then a 15 degree joint into a 1300mm piece of pipe into I think a 30 degree bend with another short piece of pipe into a 45 degree then a final short piece of pipe into the inspection chamber. (can't remember the exact angles used and there buried now)

I'm happy it will fine, the 2 angles and pieces of pipe at the bottom do give a fairly smooth curve into the inspection chamber, the shower drain with also join this pipe on a strap fitting so that should be enough water to keep it clear. It's a better setup then using 2 90's to clear the foundations would of been.

If there are any issues then I've only got to remove the rodding point on the top most bend and rod it the 1.5m ish it is into the inspection chamber but I'm happy it won't come to that.

Chris

 

[Bullet-Proof_Biscuit]

Yes that's fine as it's roddable it's perfectly acceptable

 

[Hugh Jaleak]

Keep an eye on the chamber once in use, with the soil pipe dropping so close, I have a suspicion you'll get a build up of crud on the blank channels opposite the stack connection, which could build up over time and block the chamber.

 

[^woody^]

Why didn't you fit a proper rest bend? You do all that work and then mess that up

I agree that the chamber is a bit too close and at risk of blockage - made even greater risk by using that 90 bend.

 

[thomp1983]

That bend is what I was given when I asked for a rest bend, it's a 87.5 degree bend if that makes any difference

Good news I suppose is its all accessible from a rodding and hosing point of view if it's required

 

[Deleted member 292770]

Why didn't you fit a proper rest bend? You do all that work and then mess that up

I agree that the chamber is a bit too close and at risk of blockage - made even greater risk by using that 90 bend.

Looks too tight for a rest bend. Thought one HAD to be placed at the bottom of every stack?

 

[^woody^]

That bend is what I was given when I asked for a rest bend, it's a 87.5 degree bend if that makes any difference

Good news I suppose is its all accessible from a rodding and hosing point of view if it's required

It looks a bend, not a rest bend