Why is internal sewage pipe round and not square

[Triassic]

I’m looking at installing the sewage waste pipe in the raft, this will then be in a corner of a cloak room. I as wondering why the pipe is round and not square. Square pipe would be easier to ‘hide’ inside the house. Boxed in round pipe looks so bulky!

[PeterW]

Round comes off the extrusion die and can twist slightly to no detriment. Square would have to be held true until completely cold. 

[Russell griffiths]

Why would square take up less room

100x100 square?

 

[PeterW]

So a 110mm round waste could be replaced by a 95mm square section to get the same cross section however it would be a pain to connect to as everything would have to be at 90 degrees. 

[Hecateh]

Shit collects in corners

 

[nod]

2 hours ago, Triassic said:

I’m looking at installing the sewage waste pipe in the raft, this will then be in a corner of a cloak room. I as wondering why the pipe is round and not square. Square pipe would be easier to ‘hide’ inside the house. Boxed in round pipe looks so bulky!

Cus poo would get stuck in the corners

[Ferdinand]

By the time it had collected in all the corners they would approximate round anyway.

 

? ==> ?

[AliMcLeod]

9 hours ago, Hecateh said:

Shit collects in corners

 

Sounds like a metaphor for life! ☺️

[ToughButterCup]

10 hours ago, Hecateh said:

Shit collects in corners

 

I'm listening to Radio 4.

And a report which talks about Trump and  Truth not being Truth. I wonder how Cohn could gainsay @Hecateh 's statement.  

[Hecateh]

42 minutes ago, recoveringacademic said:

 

I'm listening to Radio 4.

And a report which talks about Trump and  Truth not being Truth. I wonder how Cohn could gainsay @Hecateh 's statement.  

I think the 'truth' as spoken is very different from 'fact'

 

And the best liars are like Trump because paradoxically however disproven they have no trouble convincing themselves that what they is is true.  

[Temp]

I don't think its always necessary to use 110mm ID round pipe. I think the building regs allow soil pipes to be 80mm diameter in some situations?

[Onoff]

Purloined from elsewhere but seems reasonable:

 

Square pipes would be inferior to round pipes for several reasons.

1. Round pipes are the most efficient shape to have the largest volume to surface area ratio. A square pipe would require more energy to pump water due to more surface area to drag on. 

[jack]

For drainage with a slight fall, it also offers the best combination of flow rates for small and large volumes of water. Small volumes of water in a square (flat down) pipe would flow quite slowly.

[Ferdinand]

48 minutes ago, Onoff said:

Purloined from elsewhere but seems reasonable:

 

Square pipes would be inferior to round pipes for several reasons.

1. Round pipes are the most efficient shape to have the largest volume to surface area ratio. A square pipe would require more energy to pump water due to more surface area to drag on. 

 

Drainage pipes do not run full !

[Tyke2]

Now I know a lot of people won't agree . But I would recomend not having internal soil stacks.

Because:-

• Whilst external ones are ugly from the outside you soon fail to notice them Plus internal ones are ugly inside and mess up the aesthetics of rooms, make things hard to fit in etc.
• The plastic grommets holding in lateral pipes into th estack, can shrink and perish over time. Leaving you with waste wateer leakage inside your boxing. Not nice.
• If you must have them inside, take them throughthe roof to vent externally. Air admitance valves do fail and leave you with a smelly house.

Whilst working for th ebig developers, internal drainage pipes were the No1 pain in the butt to rectify.

 

 

[Nickfromwales]

On 20/08/2018 at 15:25, Temp said:

I don't think its always necessary to use 110mm ID round pipe. I think the building regs allow soil pipes to be 80mm diameter in some situations?

Only when its a vent and will not ever see 'other service' afaik.

[PeterW]

1 hour ago, Nickfromwales said:

Only when its a vent and will not ever see 'other service' afaik.

 

Not strictly true ....... 

 

75mm is acceptable ( see H2 of Part H BRegs) as long as it only services a single WC...!

 

But try buying the stuff ..!

[Nickfromwales]

Pan connector bores are around that size so I guess it would be permissible. Not entirely sure I’d ever have faith in King Kong’s thumb not getting stuck through  

I will have a good read of that though, cheers. 

[Onoff]

11 hours ago, Tyke2 said:

Now I know a lot of people won't agree . But I would recomend not having internal soil stacks.

Because:-

• Whilst external ones are ugly from the outside you soon fail to notice them Plus internal ones are ugly inside and mess up the aesthetics of rooms, make things hard to fit in etc.
• The plastic grommets holding in lateral pipes into th estack, can shrink and perish over time. Leaving you with waste wateer leakage inside your boxing. Not nice.
• If you must have them inside, take them throughthe roof to vent externally. Air admitance valves do fail and leave you with a smelly house.

Whilst working for th ebig developers, internal drainage pipes were the No1 pain in the butt to rectify.

 

 

 

My relative had a vertical, internal soil stack within his cavity wall that became "calcified" internally where the wc run entered at a right angle. Like a white & brown, combo stalactite and mite all at the same time. Had to have bricks removed to sort it. 

 

Of late I've seen blockages of a similar sort on site where in trying to "chip" it all off with over zealous use of "snakes" they've actually broken the pipe! 

 

With hindsight I'd still have gone "internal" and hidden a vertical stack in my mitred corner in the bathroom. Would have made future ewi so much easier!