Foul Water Drainage Layout

[andy]

Hi all

 

On site chatting with our ground worker yesterday, he was concerned about the number of 110mm penetrations through our slab the architect has indicated, which I agree with.

 

The following image illustrates the current foul water drainage plans and the associated internal use (the only additional one will be main pressure cylinder discharge via Hotun from attic space above linking in to SVP for toilet in the middle bit).

 

The floor is beam and block, followed by 300mm EPS100 then 125mm reinforced slab (don't ask, I am sure this floor will be strongest known to man).  The site is a bit of a slop going downhill from bottom to top of drawing.

 

What I am trying to work out is can I combine the waste runs within the insulated floor?  I don't know if that's permitted or not (or equally importantly, a daft idea!).  Or do I need to run additional penetrations through the floor?

 

Any thoughts on best options here?  If you need any more info, please let me know.

[Russell griffiths]

Why is he concerned on the number of penetrations, what is the problem with more ?

i have 4 toilets, 1 kitchen 1 boot room all 110mm pipes coming up

then 60mm ducts for water main, electric in,electric out,comms in, 

so 10 penetrations up through our beam and block floor 

whats the problem?

[andy]

My concern is around making sure I've got the correct amount of penetrations vs. losing thermal efficiency (I haven't modelled this to understand if it's a valid concern).

 

I want to do 110mm through the floor where it makes sense but make use of it with other inputs like sinks where I can.  For example the bottom left toilet it would be easy to run the sink into that same 110mm but the shower wouldn't make sense (both showers are using Impey formers).

[MikeSharp01]

Penetrations are relatively minor thermal concerns - we have 3 x 110mm and 16 70mm ducts coming up through ours and that represents about 0.1% of the slab area. All are closely sealed through the EPS insulation so only the plastic of the pipe / duct and the cables / pipes in the ducts will conduct heat while the air in the them will convect you can reduce this in the ducts (not the pipes) with effective sealing. They all run through ground under the slab so are not subject to air temperatures like walls would be albeit that they will be at a lower temperature than the slab so the temp delta probably won't get much above 15 degrees.

 

I think that all means you need not worry.

Edited August 31, 2019 by MikeSharp01
Typo

[andy]

That's good to confirm on the insulation side of things.

 

If I wanted to use a single 110mm SVP for additional outputs like sink or bath, is it OK to join them in the insulation layer?  Obviously inaccessible once the slab is down so would be a pretty dire situation if they went wrong!  I'm not too sure what the "norm" is here for these?

 

I will be able to do the sinks/washing machine/dishwasher as boss connections with durgos above (A1 rated if below sink flood level) but the shower wastes I think may need their own run like this if I cannot join them in (boss connections shown in green).

 

Edited August 31, 2019 by andy