Soil Pipe

[leo99]

Hello,
A plumber has just installed a new waste pipe for a new bathroom which runs approx. 7 meters. I was skeptical about his work so thought i'd have a look at what was done. The first 1 - 1.5 meters of the pipe has a slight upward incline on it (tested with a spirit level) before it declines again.
When i spoke to the plumber he said that was fine as long as the correct decline was over the full length of the pipe.
Is this right? I always thought there should be no upward incline at any point on the soil pipe...?

Thanks

 

[picasso]

Your plumber is talking ****, what size pipe are you talking about ?

 

[leo99]

Thought as much
think its a 110mm pipe.

 

[Madrab]

As Picasso mentions, waste water should never run uphill so you're plumber is talking pants.

If the run is below any trap level of the appliances connected to it and the pipe never runs above the highest level then will it cause a major problem, unlikely, but it still isn't right and should be redone. He's also running it close to the wind if there's a WC connected to it 7m+ away from the stack. Have BC been involved?

 

[leo99]

so annoying! feel like i could've done a better job myself!

the pipe is for a bathroom, so toilet, sink and bath will ultimately be connected. the middle of the pipe is running horizontal as well with no fall. I'm wondering if a spirit level is the best test for this? short of having to lift all the floor boards again and measure it up properly, is there any other way to check?
I checked BC website and they said no warrant is needed for a waste pipe.

 

[Madrab]

Take a level line from one end of the run a meter long and measure the gap from that level up or down to the pipe - min is 18mm max is 90mm - Ideal is mid 40's.

If it's just been done then get the chap playing at plumber back in, it may not need BC involvement but he still needs to follow Building Regs, it's not right and he needs to sort it.

 

[leo99]

ok. I'll try that.
thanks a lot for all the comments
appreciate it

 

[ServiceNumpty]

7mtrs in the floor void, not a hope in hells chance of any decent fall.

 

[leo99]

i thought there was more than enough room?
Length is 7 meters
The pipe is 110mm
the available space under the floor is 200mm, leaving us with 90mm to work with

gradient = 0.09m / 7m
= 1 in 77

or did i work that our wrong?

 

[Madrab]

If you have the space to drop a soil pipe 200mm in the floor void over 7m, then that'll give you a fall of just shy of 30mm per/m so should be ok, not ideal tho and it shouldn't rrreally be longer than 6M. It does need set out correctly and supported though to ensure it gets that 200mm run on it.

 

[picasso]

The min fall is 18mm per metre and the max is 90mm per metre, you dont have the min fall needed to ensure your drain is self cleaning, it will probably work ok but I would ensure you have rodding access points that you can actually get to.

@Madrab the 200mm is taken up by the pipe being 110 so the op has a drop of 90mm.

 

[Madrab]

Doh, cheers P, that'll teach me to read things properly while I'm at me dinner lol I read it as the OP has the space to drop the pipe by 200mm, not that there is only 200mm of space , totally missed the 90mm to work with part of that sentence

OP - 13mm Per M fall, not nearly enough, time for your plumber to re-think I'm afraid.

 

[Madrab]

duplicate

 

[leo99]

thanks guys. appreciate your comments

 

[Hugh Jaleak]

If it isn't already, it needs to be ventilated as well over that distance.