In order to save kitchen space, I was looking at fitting a washing
machine in an upstairs hall cupboard. The drain would have to run under
the hall and across the bathroom in the suspended floor space. The
joists run with the drain route, so no problem getting the drain under
the floor. The water is pumped by the washing machine and using a clamp
on non-return valve connector on the drain pipe I don't see any
problems. Does the drain need a strong fall to it?

Another point is that can the drain pipe be in a 'U' shape? The
pipe drops from the washing machine, under the floor and then rises up
and connects onto the 110mm WC pipe. Water will be trapped in this
pipe. As the washing machine pumps water via a non-return valve I
can't see this being an issue. This would make matters much easier.

Any comments welcome.

----- Original Message -----
From:
Newsgroups: uk.d-i-y
Sent: Thursday, June 01, 2006 1:19 AM
Subject: Washing machine drain


In order to save kitchen space, I was looking at fitting a washing
machine in an upstairs hall cupboard. The drain would have to run under
the hall and across the bathroom in the suspended floor space. The
joists run with the drain route, so no problem getting the drain under
the floor. The water is pumped by the washing machine and using a clamp
on non-return valve connector on the drain pipe I don't see any
problems. Does the drain need a strong fall to it?

Another point is that can the drain pipe be in a 'U' shape? The
pipe drops from the washing machine, under the floor and then rises up
and connects onto the 110mm WC pipe. Water will be trapped in this
pipe. As the washing machine pumps water via a non-return valve I
can't see this being an issue. This would make matters much easier.

Any comments welcome.


You don't need a 'strong fall' at all, although this would help if you are
emptying out over a long distance, what you do need is a minimum height
above the floor level of the machine to stop the water syphoning out
mid-cycle. Usually the machine will have a red line or some sort of
indicator at the back of the machine to show the minimum height required for
the pipe. As long as it goes above this height for some part of the journey,
preferably close to the machine, I don't see any problems.

Ian Tilley

AIUI the drainage pipe should have a u-bend trap and a 1 in 40 fall
over it's whole length. The underfloor bit sounds fine, the rises up
and enters the soil pipe bit doesn't. The rises up bit sounds like
there would be quite bit of water pooling there, where debris will
collect and eventually block the pipe. The connection to the soil pipe
may have the potential to allow sewage back into the washing machine
drainage pipe. Check the building regs, they have things to say about
distances and directions for drainage pipes connecting to soil pipes.

In order to save kitchen space, I was looking at fitting a washing
machine in an upstairs hall cupboard. The drain would have to run under
the hall and across the bathroom in the suspended floor space. The
joists run with the drain route, so no problem getting the drain under
the floor. The water is pumped by the washing machine and using a clamp
on non-return valve connector on the drain pipe I don't see any
problems. Does the drain need a strong fall to it?

The pump of the washing machine isn't intended for long tortuous runs like
this. It should empty into a trap near the machine.

However, all is not lost. You can buy pumps which are intended for this
purpose. The Saniflo range would not be suitable as they do not allow a
vertical run at the end, only at the beginning. However, a Sanisplit K2
(different company) should do the trick. They're not cheap, though. The
other alternative is to run by gravity to the base of the vertical run and
then install a Sanivite at that point, rather than near to the washing
machine. However, it won't be any cheaper and probably a whole lot less
convenient.

Christian.

On Thu, 1 Jun 2006 10:05:32 +0100 someone who may be "Christian
McArdle" wrote this:-

The Saniflo range would not be suitable as they do not allow a
vertical run at the end, only at the beginning.

One can go from the 22mm Saniflo outlet pipe to a larger size near
the vertical drop though. This will allow air in and thus not siphon
the whole of the 22mm pipe.

Using such a device may also allow other locations to be considered.

While any added complication is best avoided if possible these pumps
are useful in some situations and work happily for a long time if
not abused.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

One can go from the 22mm Saniflo outlet pipe to a larger size near
the vertical drop though. This will allow air in and thus not siphon
the whole of the 22mm pipe.

My understanding is that the pipe rises vertically at the end, rather than
dropping. If it dropped, then it would probably be possible to design a
gravity system.

Christian.

The message
from "Christian McArdle" contains
these words:

The pump of the washing machine isn't intended for long tortuous runs like
this. It should empty into a trap near the machine.

I've run several washing machines discharging via lengths of long pipe
and never had any problems. The longest was about six meters of 32mm
pipe just lying on the floor along behind some units, round a bend,
behind more units and into a spigot on the sink outlet. Ran for years
without trouble. The pumps are very simple, and worst comes to the
worst, they're under a fiver off eBay.

--
Skipweasel
Pay no attention to that man behind the curtain.

On Thu, 1 Jun 2006 11:13:23 +0100 someone who may be "Christian
McArdle" wrote this:-

My understanding is that the pipe rises vertically at the end, rather than
dropping.

It isn't clear whether the plan is to install a pipe that rises at
the end, or it already does. If it is just a plan then a vertical
rise at the end certainly does not comply with the Saniflo
instructions and thus would undoubtedly invalidate the warranty.

However, I was thinking of changing the pipe design so that at the
end it dropped onto the stack far enough away from the toilet
connection.

Of course with a Saniflo it might well be easier and better to go up
from the first floor cupboard and through the loft (assuming a two
storey house) to the stack. This would avoid a lot of difficult work
under the floor and could all be done in 22mm pipe, assuming the
length is suitable. It would probably be a matter of pulling a few
bends in copper pipe and clipping it to suitable places. The stack
connection would also be much easier. I would bond the pipe and it
certainly should be insulated in the loft. Costing labour and
disruption against the cost of the unit this might even be cheaper
considered in the round. From memory only the Saniflo itself cannot
pump vertically, the others in the range can pump up to something
like 3m. I can't be bothered to look at the web site to check.

If it dropped, then it would probably be possible to design a
gravity system.

Indeed.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

If it is just a plan then a vertical rise at the end certainly
does not comply with the Saniflo instructions and thus would
undoubtedly invalidate the warranty.

Indeed. The Sanisplit, on the other hand doesn't have this restriction,
which is why I would recommend it if this pipe routing was chosen.

Of course with a Saniflo it might well be easier and better to go up
from the first floor cupboard and through the loft (assuming a two
storey house) to the stack. This would avoid a lot of difficult work
under the floor and could all be done in 22mm pipe, assuming the
length is suitable.

Yes, that would probably be a preferable routing if feasible.

Christian.

Christian McArdle wrote:
If it is just a plan then a vertical rise at the end certainly
does not comply with the Saniflo instructions and thus would
undoubtedly invalidate the warranty.

Indeed. The Sanisplit, on the other hand doesn't have this restriction,
which is why I would recommend it if this pipe routing was chosen.

Of course with a Saniflo it might well be easier and better to go up
from the first floor cupboard and through the loft (assuming a two
storey house) to the stack. This would avoid a lot of difficult work
under the floor and could all be done in 22mm pipe, assuming the
length is suitable.

Yes, that would probably be a preferable routing if feasible.

Christian.

Thanks to all.

The length of the drain pipe from washing machine under the floor is
about 15 foot, 5 metres. At a 1 in 40 fall (that is falling 1 cm for
every 40 cm in length) that is a pipe fall of about 10cm. That will
just be enough space in the floor. I can take the pipe out of the
outside wall which opens up into the roof space of the brick lean-to
kitchen. From this space I can then take the pipe outside via the side
of the lean-to and down into a gully below.

I can take the drain pipe across the floor, rise and connect onto the
toilet 110mm elbow. It could rise 3 foot so no soil from the toilet can
run into the washing machine drain. The Sanisplit pump should be
capable of doing this. Can I tee into the soil stack just behind the
toilet? I see no reason why not as long as the pipe rises above the WC
pan preventing backflow.

If this is not feasible because of obstructions, the Sanilav, which
uses 22mm pipe can rise up and across the loft and connect onto the
stack outside. It may be tricky getting the 22mm pipe out of the eves.
Does it have to be copper pipe? Sanilav have a model that is about
£210 for basins and showers. Would this do a washing machine and
condensing dryer? I can't see why not. I "think" it has a 22mm
discharge pipe.

The message .com
from contains these words:

Another point is that can the drain pipe be in a 'U' shape? The
pipe drops from the washing machine, under the floor and then rises up
and connects onto the 110mm WC pipe. Water will be trapped in this
pipe.

Washing machine pipes are always full of water.

I really think you're making this more complicated than it needs to be.
If you're in any doubt about whether the washing machine pump will cope,
make a mock-up with a length of 32mm waste pipe laid on the floor and
you'll see it'll cope no trouble.

--
Skipweasel
Pay no attention to that man behind the curtain.

On Thu, 1 Jun 2006 20:04:56 +0100, Guy King
wrote:

The message .com
from contains these words:

Another point is that can the drain pipe be in a 'U' shape? The
pipe drops from the washing machine, under the floor and then rises up
and connects onto the 110mm WC pipe. Water will be trapped in this
pipe.

Washing machine pipes are always full of water.

I really think you're making this more complicated than it needs to be.
If you're in any doubt about whether the washing machine pump will cope,
make a mock-up with a length of 32mm waste pipe laid on the floor and
you'll see it'll cope no trouble.

That's far too pragmatic...

The message
from Pete C contains these words:

That's far too pragmatic...

Ah, sorry, I forgot this is uk.mountains-from-molehills!

--
Skipweasel
Pay no attention to that man behind the curtain.

"Guy King" wrote in message
...
The message .com
from contains these words:

Another point is that can the drain pipe be in a 'U' shape? The
pipe drops from the washing machine, under the floor and then rises up
and connects onto the 110mm WC pipe. Water will be trapped in this
pipe.

Washing machine pipes are always full of water.

I really think you're making this more complicated than it needs to be.
If you're in any doubt about whether the washing machine pump will cope,
make a mock-up with a length of 32mm waste pipe laid on the floor and
you'll see it'll cope no trouble.

Most washing machine drain pipes I find that don't have a good fall, or are
straight, end up being fully or partially blocked with gunge.

The best is gravity of course, using slow bends where used. Using a Sanilav
or Sanisplit pump is the last resort but should work well. Even the gravity
fall pipe I would have accessible rodding points at every opportunity. One
could be at the washing machine end under the floor of the cupboard the
washing machine is to go. Have an easily removable trap. I would use solvent
weld pipe and fittings. I would also occasionally use Mr Muscle drain
unblocker down the drain pipe to burn away any gunge.

If using 22mm pipe and a Sanilav pump I would also put rodding points in, or
have compression joints in the loft to easily break the pipe and get a rod
in.

The message ews.net
from "Doctor Drivel" contains these words:


Most washing machine drain pipes I find that don't have a good fall, or are
straight, end up being fully or partially blocked with gunge.

All I can say is it's never happend to me on several long washing
machine drains and two dishwasher drains - though they weren't so long,
only about two meters.

--
Skipweasel
Pay no attention to that man behind the curtain.

On 1 Jun 2006 09:46:13 -0700 someone who may be
wrote this:-

Can I tee into the soil stack just behind the
toilet?

Unless the connection uses one of the patent fittings then the new
connection must be more than IIRC 100mm from the toilet connection.

If this is not feasible because of obstructions, the Sanilav, which
uses 22mm pipe can rise up and across the loft and connect onto the
stack outside. It may be tricky getting the 22mm pipe out of the eves.
Does it have to be copper pipe?

They have a web site with lots of details. From memory pushfit
joints (obviously) and flexible pipe are frowned upon.

Sanilav have a model that is about
£210 for basins and showers. Would this do a washing machine and
condensing dryer? I can't see why not. I "think" it has a 22mm
discharge pipe.

They do a few models designed specifically for the hot waste from
washing equipment.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54