Required drop for toilet outflow
 

Hi group...

My Dad currently has an en-suite bathroom powered by a macerator.
However he wishes to convert this to a normal flush only, but is
concerned about the required fall for the waste pipe. Does anybody
know what the required angle of elevation is for the waste pipe of a
flush toilet?

thanks to anyone who takes the trouble to respond.

regards


paul

Required drop for toilet outflow
 

The Natural Philosopher wrote:

grimmy wrote:

Hi group...

My Dad currently has an en-suite bathroom powered by a macerator.
However he wishes to convert this to a normal flush only, but is
concerned about the required fall for the waste pipe. Does anybody
know what the required angle of elevation is for the waste pipe of a
flush toilet?


1:100 minuimum 1:60 ideal from memory.

There's other issues as well- best consult an architect or decent
builder, or look up the building regs...you need biogger pipes than the
macerator as well, and where they join the downpipe is subject to issues
to avoid blowback into the bath etc :-)

thanks to anyone who takes the trouble to respond.

regards


paul


Standard fittings, (branches, bends etc) all have 92.5 or 87.5 degree angles
so I assume the fall should be 2.5 degrees.

Bob

Required drop for toilet outflow
 

Bob Minchin wrote:

The Natural Philosopher wrote:


grimmy wrote:


Hi group...

My Dad currently has an en-suite bathroom powered by a macerator.
However he wishes to convert this to a normal flush only, but is
concerned about the required fall for the waste pipe. Does anybody
know what the required angle of elevation is for the waste pipe of a
flush toilet?


1:100 minuimum 1:60 ideal from memory.

There's other issues as well- best consult an architect or decent
builder, or look up the building regs...you need biogger pipes than the
macerator as well, and where they join the downpipe is subject to issues
to avoid blowback into the bath etc :-)


thanks to anyone who takes the trouble to respond.

regards


paul



Standard fittings, (branches, bends etc) all have 92.5 or 87.5 degree angles
so I assume the fall should be 2.5 degrees.

Bob


which is 1:22

That is way more than is required.

Required drop for toilet outflow
 

The Natural Philosopher wrote:

Bob Minchin wrote:

The Natural Philosopher wrote:


grimmy wrote:


Hi group...

My Dad currently has an en-suite bathroom powered by a macerator.
However he wishes to convert this to a normal flush only, but is
concerned about the required fall for the waste pipe. Does anybody
know what the required angle of elevation is for the waste pipe of a
flush toilet?


1:100 minuimum 1:60 ideal from memory.

There's other issues as well- best consult an architect or decent
builder, or look up the building regs...you need biogger pipes than the
macerator as well, and where they join the downpipe is subject to issues
to avoid blowback into the bath etc :-)


thanks to anyone who takes the trouble to respond.

regards


paul



Standard fittings, (branches, bends etc) all have 92.5 or 87.5 degree angles
so I assume the fall should be 2.5 degrees.

Bob

which is 1:22

That is way more than is required.





Maybe this is too steep but how do you avoid using 2.5 degrees when the fitting
all come like this?

Maybe you know of a source of other fittings

Bob

Required drop for toilet outflow
 

"grimmy" wrote in message
m...
Hi group...

My Dad currently has an en-suite bathroom powered by a macerator.
However he wishes to convert this to a normal flush only, but is
concerned about the required fall for the waste pipe. Does anybody
know what the required angle of elevation is for the waste pipe of a
flush toilet?

thanks to anyone who takes the trouble to respond.

regards


paul

A good rule of thumb Paul, is a 10 mm drop for every 1 mtr of pipe length.
Remember also that bends will have to follow this same requirement, so if
the bend popping through the wall is part of a 1 mtr measurement, then it
needs to follow the rule of 10 mm drop per 1 mtr of length.


---
www.basecuritysystems.no-ip.com
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.505 / Virus Database: 302 - Release Date: 30/07/03

Required drop for toilet outflow
 

From the chaotic regions of the Cryptosphere,
(grimmy) wrote on 31 Jul 2003 12:23:19 -0700:

Does anybody
know what the required angle of elevation is for the waste pipe of a
flush toilet?

The above-ground branch needs to have a fall between 18mm and 90mm per
metre run. The below ground drain needs to be no shallower than 1:40.
--
Hugo Nebula
"You know, I'd rather see this on TV,
Tones it down" - Laurie Anderson

Required drop for toilet outflow
 

From the chaotic regions of the Cryptosphere, Bob Minchin
wrote on Thu, 31 Jul 2003 22:13:02 +0100:

The Natural Philosopher wrote:

which is 1:22

Maybe this is too steep but how do you avoid using 2.5 degrees when the fitting
all come like this?

The gradient for _above-ground_ WC branches are between 18mm-90mm per
metre, which works out to 1:55 to 1:11, which works out to between
1.03° - 5.14°. So 2.5° is pretty much slap-bang in the middle.

Rest of the world 1, Natural Philosopher 0.
--
Hugo Nebula
"You know, I'd rather see this on TV,
Tones it down" - Laurie Anderson

Required drop for toilet outflow
 

Hugo Nebula wrote:

From the chaotic regions of the Cryptosphere,
(grimmy) wrote on 31 Jul 2003 12:23:19 -0700:


Does anybody
know what the required angle of elevation is for the waste pipe of a
flush toilet?


The above-ground branch needs to have a fall between 18mm and 90mm per
metre run. The below ground drain needs to be no shallower than 1:40.



Not so. Below ground its advised to be between 1:60 and 1:100 and IIRC
not STEEPER than 1:40

Required drop for toilet outflow
 

Hugo Nebula wrote:

From the chaotic regions of the Cryptosphere, Bob Minchin
wrote on Thu, 31 Jul 2003 22:13:02 +0100:


The Natural Philosopher wrote:


which is 1:22


Maybe this is too steep but how do you avoid using 2.5 degrees when the fitting
all come like this?


The gradient for _above-ground_ WC branches are between 18mm-90mm per
metre, which works out to 1:55 to 1:11, which works out to between
1.03° - 5.14°. So 2.5° is pretty much slap-bang in the middle.

Rest of the world 1, Natural Philosopher 0.


"A minimum size 100mm branch pipe may be used for a maximum of 8 WC's or
a length not exceeding 15m, gradient should be between 9mm and 90mm per
meter run" Building regs 2000 edition.

From building regs. So min fall is 1:100 roughly.

Since this is a macerator replacement, he will want to work as near flat
as possible.


The steeper gradients you quote are for washbasins and urinals and baths
on smaller diameter pipes.

External falls depend on anticipated flow rate - i.e. number of bogs
connected, and may be in large diamter pipe as low as 1:180. though
1:40- 1:80 is optimum. 1:60 is a good working figure.

Required drop for toilet outflow
 

From the chaotic regions of the Cryptosphere, The Natural Philosopher
wrote on Fri, 01 Aug 2003 09:36:23 +0100:

Hugo Nebula wrote:

Rest of the world 1, Natural Philosopher 0.

"A minimum size 100mm branch pipe may be used for a maximum of 8 WC's or
a length not exceeding 15m, gradient should be between 9mm and 90mm per
meter run" Building regs 2000 edition.

The Building Regulations don't give guidance, the Approved Documents
do. (2-0) Perhaps you should download the 2002 edition of AD 'H'
(Drainage). (3-0)

Table 2 Common branch discharge pipes (unventilated) gives the
gradient limits as:


Appliance |Max no. to |Gradient limits
|be connected|mm fall per metre)
__________________________________________________ __
WC outlet 80mm |8 |18(2) to 90
WC outlet 80mm |1 |18 to 90

The footnote (2) to this table reads "May be reduced to 9mm on long
drain runs where space is restricted, but only if more than 1 WC is
connected". So for the OP's question relating to a single WC, then
the minimum fall is 1:55 (4-0)

So min fall is 1:100 roughly.

Very roughly. (Poor defending nearly let another in)

The steeper gradients you quote are for washbasins and urinals and baths
on smaller diameter pipes.

The lower end of the gradient range is uniform at 18mm/metre(1) across
the whole range of appliances. (5-0)

External falls depend on anticipated flow rate - i.e. number of bogs
connected, and may be in large diamter pipe as low as 1:180. though
1:40- 1:80 is optimum. 1:60 is a good working figure.

The OP was about sanitary (above-ground) drainage. It sounds like
you're getting this confused with the drains below ground. I don't
know of any unpumped drainage serving normal domestic foul drainage
that can be installed at 1:180! (6-0)

(1) In the UK we use the "metre" spelling for the measure of distance.
7-0 in injury time)
--
Hugo Nebula
"You know, I'd rather see this on TV,
Tones it down" - Laurie Anderson