Soil pipe run of 8m - possible?

[weatherbadger]

Hello

I'm wondering if I can replace a Saniflow in a loft shower-room using 110mm soil pipe.

The soil pipe run would be:
135deg bend at back of toilet.
1.5m straight.
90deg bend (I could do this as 2x 135degs)
5.5m straight.
then a 90deg turn to the outside stack.

Total length ~8m, with around 10cm drop (which I think is okay).

I know building regs advise a 6m limit to a horizontal soil run. So am I stuck with the Saniflow?

There would be a shower/basin joining the soil-pipe behind the loo, with some anti-syphon thing. Perhaps this would help flush things along (including the building regs folks?)

Thanks for your thoughts.

James

 

[rpm]

Isn`t it 18mm - 25mm per metre fall?

 

[Riley]

Isn`t it 18mm - 25mm per metre fall?

:iagree:

 

[weatherbadger]

Hello, thanks for looking.
The bottom of the soil pipe at the back of the loo is ~12-13cm from the floor and there would be a 7m run til it goes out of the roof. 7x0.18=12.6cm so I think I would be around okay, or could raise the loo up 1 cm to be safe.
However, I'm mainly concerned about exceeding the 6m.

 

[Riley]

You could add additional ventilation. The regs are there for a reason though. Is this a new bathroom

 

[weatherbadger]

It's a 10 year old loft conversion. Then, the saniflow (which pumps up and over to get to the downpipe) was deemed the easiest option.

If I fitted an air admittance valve where would this best go?

 

[rpm]

James, is this your property or something you are pricing up to quote for, because your last sentence in post #4 worries me tbh.

 

[weatherbadger]

Ha - rumbled! It's my property. I would be happy replacing the knackered Saniflow myself, but if fitting a soil pipe is do-able then I'll get someone in.

 

[rpm]

Ha - rumbled! It's my property. I would be happy replacing the knackered Saniflow myself, but if fitting a soil pipe is do-able then I'll get someone in.

That's fair enough mate however don't squeeze the numbers to make them suit or it could backfire.

 

[weatherbadger]

Yes, cheers for your thoughts. I think being over the recommended limits, means I'll stay Saniflow. Plus it'll be cheaper.

 

[rpm]

Pray no power cuts then. Take a look at the Saniaccess but note the higher side inlets.

 

[weatherbadger]

I'm expecting they've got a lot quieter in the last 10 years.

 

[rpm]

I'm expecting they've got a lot quieter in the last 10 years.

Getting late I'll reply tomorrow

 

[tamz]

A 1:80 fall will work perfectly well but can be quite hard to achieve uniformly once bends are introduced.
Just check for dips using a long level (maybe in conjunction with a long straight edge) or a laser and clip or otherwise fix the pipes in position.
Make sure you fit handholes on 90's and branches and fit a durgo at the highest point. It will only cost an extra 30 or 40 £

 

[rpm]

A 1:80 fall will work perfectly well but can be quite hard to achieve uniformly once bends are introduced.
Just check for dips using a long level (maybe in conjunction with a long straight edge) or a laser and clip or otherwise fix the pipes in position.
Make sure you fit handholes on 90's and branches and fit a durgo at the highest point. It will only cost an extra 30 or 40 £

Would 1:80 pass building regs Tamz?

 

[tamz]

Do you really thing they would gaf?

1:100 is minimum for a 4" but very hard to achieve accurately due to plastic pipes having a bow in them (as the size goes up so does the min gradient ie 6" pipe 1:150, 8" pipe 1:200 etc etc. Do you think a shyte knows what size pipe it is in

 

[rpm]

I'm expecting they've got a lot quieter in the last 10 years.

After 10yrs I would expect yours to be way down on discharge pressure and noisy so yes it will be quieter. If you put a new one in then use carpet or underlay underneath it and behind if it`s touching a wall as anti-vibration pads and if you want to go the full monty then construct a simple 4 panel box around it and fill the box with loft insulation up to but not over the lid.