Hi All

 

I've just been pondering my soil pipe locations.

 

Am I right in assuming that best practice is to take the soil run outside to a chamber as quickly as possible to aid rodding etc?

As you can see in the attached picture I've assumed that scenario, but could equally have a single run under the slab but that seems like a massive issue if there were ever a blockage. 

I also assume that more soil pipe locations is much better than long lengths of 40/50mm waste?

All of the chambers shown are to the North of the property in a fairly narrow access strip so there are no asthetic issues at all.

 

Here's the layout:

 

I have worked on 2 principals, keeping the soil/waste locations as close together to minimize travel and also to minimize penetrations into the shell.  That said I have kept it to 3 full size 110mm soil penetrations through the slab.  Two are close together because of a ground floor wet room shower forcing a second one near the main stack.  The third serves 2 en-suites and the kitchen.

Soil.pdf

If it were me I would run the pipe outside as you suggest Barney, others may differ but to run the pipe inside under concrete slab would be a major pain in the arse and mess up your rooms if anything went wrong. Imagine having a big hole punctured though your floor and how unpleasant it would look particularly guest are around at a seasonal time of the year, smell might penetrate into the house more also. 

Consider flipping your WC and plant room so you only have one soil pipe instead of two.

The furthest soil pipe (e.g WC) generally has to be vented to the outside anyway, which might be an issue.

 

Otherwise I would stick with the orange lines.

I'm working on a property where the soil pipe runs under the slab and it's caused no end of problems albeit 30-50 years after it was initially laid.

On 11/24/2016 at 17:54, bassanclan said:

Consider flipping your WC and plant room so you only have one soil pipe instead of two.

The furthest soil pipe (e.g WC) generally has to be vented to the outside anyway, which might be an issue.

 

 

Flipping them isn't going to be an option (I wont bore you with why).

So does the AAV also have to be as high as possible or can the AAV be on a ground floor stub?

Answering my own question I see that McAlpine make an AAV which can be placed below the flood level. 

So I'm wondering if this is the best layout? 

You can see that our ground floor is bigger than the upper so I have the roof/loft void for pipe runs. 

 

I hate indoor soil pies, noisy, draughty big time, difficult to access or work on.

 

never have any drain in kitchen or utility, nightmare when gulley blocks, outdoor gulley, outside tap over it easy to clean, use accessible gulley and it can be Y'd into drain run.

 

re manholes and short pipes, I minimise manhole numbers, try to combine entries I think you only need one or possibly two inspection chambers.

 

I don't like aav at head of run,prefer vent

 

 

I don't think you will get away with an AAV where you have indicated.

Usually furthest away from the mains sewer your building control officer will want to  see it vented to the outside.

1 hour ago, bassanclan said:

I don't think you will get away with an AAV where you have indicated.

Usually furthest away from the mains sewer your building control officer will want to  see it vented to the outside.

I agree with that.

 

I wanted to avoid a vent through the roof. The end of my run is actually the static caravan which has a vented stack, so I argued that I only needed an AAV in the house. But BC would not accept that saying there must be at least one vent from the house.  That house vent could be just a stack running up the outside of the house, but I think that would have looked awful, so I went for a vent through the roof.
 

2 hours ago, ProDave said:

I agree with that.

 

I wanted to avoid a vent through the roof. The end of my run is actually the static caravan which has a vented stack, so I argued that I only needed an AAV in the house. But BC would not accept that saying there must be at least one vent from the house.  That house vent could be just a stack running up the outside of the house, but I think that would have looked awful, so I went for a vent through the roof.
 

Well I did similar, the end stack for me is my garage ( inside toilet) so no stack on the house, BCO accepted that.

4 minutes ago, joe90 said:

Well I did similar, the end stack for me is my garage ( inside toilet) so no stack on the house, BCO accepted that.

You can well argue that a garage is permanent. I argued I had no intention of removing the static caravan, but BC would not accept that, saying any future owner of the house may remove it and cap the drain leaving it with no vent.
 

Dave, Could you not put a stack on the house coming out of the ground and simply remove it and plug the hole after inspection as long as you put one next the the van?

I cold have done, if I had known of this requirement, I could have ran a stack up the gable end of the garage. But by the time I kenw about it, that was already concreted over as a parking space, so we will live with the stack through the roof now.
 

Interesting views. The end of our run is actually the garage, which has the flat above. Ironically no AAV and no external vent.

At the time of building it the old house was still there but that also had no external vent or AAV.

The BCO never queried the lack of vent or AAV when we built it. 

 

Everything runs into our own sceptic tank (which we think dates from the 1950's) and works exceedingly well. 

Our BCO (independent) did not make us have an external vent as he felt the neighbours would keep the street system ventilated. We have AAVs internally at the top of each soil stack. We were told by him that on new build estates, only 1 in 10 need external vents.

56 minutes ago, Bitpipe said:

Our BCO (independent) did not make us have an external vent as he felt the neighbours would keep the street system ventilated. We have AAVs internally at the top of each soil stack. We were told by him that on new build estates, only 1 in 10 need external vents.

 

Does anyone know if having your own septic tank changes the situation at all? 

It strikes me that by its nature its fairly well ventilated anyway! 

Just now, Barney12 said:

 

Does anyone know if having your own septic tank changes the situation at all? 

It strikes me that by its nature its fairly well ventilated anyway! 

 

The BCO explained it to me as this

- the AAVs (or equivalent) are there to ensure that your system works properly, preventing pressure drops in the system upon flushing that may cause water in other u-bends to be sucked out.

- The final air vent is to ventilate the sewer system as a whole and is not critical to performance of your system, effectively you're being a good citizen.

 

Therefore as both neighbours either side of us and the one opposite have SVPs, we can do without.

 

That said, the plumber was a bit sceptical and suggested we still needed one (would have required penetrations through flat roof so I was understandably reluctant). We have a soil run to the (soon to be removed) caravan to the rear of the house, so we could fit a vent to that and hide in a flower bed or something. 

1 minute ago, Bitpipe said:

 

That said, the plumber was a bit sceptical and suggested we still needed one (would have required penetrations through flat roof so I was understandably reluctant). We have a soil run to the (soon to be removed) caravan to the rear of the house, so we could fit a vent to that and hide in a flower bed or something. 

 

Our's would have to penetrate our metal seam roof (zink, or possibly ColourCoat Urban IF I can get the park to agree) so I'm also equally reluctant. 

It would be incredibly simple for me to vent the system on the run down to the septic tank. 

Looks like I'll have  to see what the BCO says when we get there.

2 minutes ago, Bitpipe said:

That said, the plumber was a bit sceptical...

 

You're using the same plumber I did, yes?  He expressed some scepticism in our situation as well.

 

From memory, this all happened around the time of the big discussion on ebuild about the potential chimney effect of an uninsulated (or at least poorly insulated) SVP in a highly insulated house.  We didn't use AAVs anywhere, and ended up with everything venting via an SVP on the roof.  We did manage to realise what was going on in time to at least limit it to a single SVP - originally there were two.  

 

Because we don't have AAVs, I was planning to look into an exterior AAV to try and reduce the chimney effect.  Apparently they work okay, although I suspect they quickly end up not completely sealing.  Still better than a completely open pipe, I suspect.

 

5 minutes ago, Barney12 said:

It would be incredibly simple for me to vent the system on the run down to the septic tank. 

 

I'm sure someone (Jeremy?) had a vented a treatment system that satisfied the need for sewer venting without the need for a separate SVP.

 

Just another case of building regs not being consistent across the country!.

Our BCO is happy for us to have an open vent in the garden off the sewage treatment plant and AAVs in the house.

23 hours ago, ProDave said:

You can well argue that a garage is permanent. I argued I had no intention of removing the static caravan, but BC would not accept that, saying any future owner of the house may remove it and cap the drain leaving it with no vent.
 

There is a "one property in 10" rule you could have used there perhaps. I've got away with no vent at all on some jobs where I can clearly demonstrate that 5 houses down and 5 houses up have vents.

The difficulties from there are probably exasperated by you being detached. 

Personally, Dave, I'd get my completion cert and drop the vent out of the house roof and leave the plant vent do the job. 

BCO's sometimes need to chill out a bit, but they're just covering their arses most of the time which makes them over-cautious.