Self build underground pipe runs

[Rishard]

I’m just about to set out some of my 110mm soil pipes. On the architects plans we have picked the shortest route to the outside of the building which seems sensible. I have a kitchen waste at the rear of the build which on plan is going around the outside of the house to join the other soil pipes. 
 

My first question is, 

 

Would it make sense to try come through the building to join the other soil pipes as a more direct route? Or is this a plumbing no no for some reason? 
 

My second question is, 

 

The 2 soil pipes which are in the utility and wc/shower room. I’m imagining a swept bend coming up to a vertical pipe through the slab. Is this the point where all the shower room and w/c connections are made or should I have 1 for the w/c and 1 for the shower room as they are separate rooms? 
 

Which of these pipes needs a rodding eye if any? 
 

I gather the stack which runs up the utility to upstairs will be ok to have an AAV in an accessible place, is this correct? 
 

Thanks in advance 

 

I have attached floor plans and foundation plans. 

[kandgmitchell]

This begs the questions:

 

How is the master en-suite drained?

How are the guest wc and shower drained?

 

There needs to be a basin in the cloakroom wc.

 

Normally the head of the run is vented direct to atmosphere.

 

You could run the kitchen gulley across under the building to connect to one of the side IC's

 

Ground floor showers connected to stacks can be a problem as the waste can hit the stack in the bend area if it's not properly planned. You could raise the tray and use a manifold or if against an outside wall pop the waste out to a gully as just two of several alternatives.

 

Never have liked rodding eyes on stacks. By the time you know it's blocked the level could be well above that eye and opening it into your house isn't nice! With an external IC you should be able to rod right into that bend to clear it. 

[Rishard]

I forgot to mention, I’m using pozi joists for this build. Which have a 200mm clear space between the cords which I can as planing on using to service the master en-suite. 
 

The w/c would have a basin, just not on the plan. 
 

Could the guest shower room not link to the drain run coming from the w/c?
 

I have plenty of fall to the main drain so can set my bends very low below the slab if it helps. 
 

I don’t like the idea of drilling holes through the wall to connect up externally. Ideally most should come up through the slab. 
 

 

[kandgmitchell]

Ok for the master en-suite then - just watch the length of the basin waste - you may need an anti-syphonic trap to stop it gargling.

 

You don't want to "Y" on the guest room WC to the cloakroom run as you'll have a junction under the floor with no access (other than taking off the pan) as a rod will just push straight past when introduced from the IC. Take that WC out to the IC direct.  The shower depends on the type of tray you are fitting, as running a 40mm waste through a floor slab given the tendency to "slime" up with hair and soap etc never seems a good idea.

 

As for connections to stacks see Diagram 2 in the Approved Document H as well (your BCO will have!).

[Rishard]

That’s helpful information. Ideally the guest shower room would have wet room plumbing for the shower. I still need to look in to how to achieve this. 

Is it just w/c’s that want a direct route to IC?

Are basin wastes ok going into a Y in a pipe run?

 

Same with kitchen sink, can that be in the run that connects to the stack which runs upstairs? Swept bend at base of the stack joining a Y coming from kitchen sink to IC?