Just been deciding which system of waste water pipes to use.

I'm in favour of solvent weld for most of it and universal compression
joints for the u-traps and anything else where it's needed.

I'm aware that solvent weld pipe (32 or 40mm) is differemt and incompatible
with push fit (32 or 40mm).

Is solvent weld the correct stuff to go onto a 110mm boss adaptor (not strap
on - proper adaptor with several 40mm inlets) and is this joint solvent
welded or should I be looking for a coupling piece of some sort?

I've got a bit of 110mm sticking up out of the floor that needs 3 x 40mm (or
2x40 and 1x32) fed into it (distant bath, entire kitchen - also distant,
plus local basin - it's under the sing in the shower room). I will remember
to put Durgo valves in appropriate places too.

Ta muchly

Tim

On Mon, 26 Jan 2009 01:24:01 +0000, Tim S wrote:

I'm in favour of solvent weld for most of it and universal compression
joints for the u-traps and anything else where it's needed.

Are any of the joints going to be hidden or are they all accessable? If
they are hidden use solvent weld, it won't push apart should you ever need
to physically clean the pipe with a rod or springy thing.

Is solvent weld the correct stuff to go onto a 110mm boss adaptor (not
strap on - proper adaptor with several 40mm inlets) and is this joint
solvent welded or should I be looking for a coupling piece of some sort?

At that point I'd use a dismantable joint assuming you have access. So you
can get at and open the pipe at that point, again for cleaning blockage
removal.

Is 40mm enough for a whole kitchen? We have a long 40mm from the kitchen
and it only just copes with sink and washing machine and has blocked once
but then one bit only just has enough fall. The Grand Scheme Of Things has
this replaced with 50mm...

--
Cheers
Dave.

Dave Liquorice coughed up some electrons that declared:

On Mon, 26 Jan 2009 01:24:01 +0000, Tim S wrote:

I'm in favour of solvent weld for most of it and universal compression
joints for the u-traps and anything else where it's needed.

Are any of the joints going to be hidden or are they all accessable? If
they are hidden use solvent weld, it won't push apart should you ever need
to physically clean the pipe with a rod or springy thing.

Hi Dave,

Potentially all accessible (inside a long airing cupboard)

Is solvent weld the correct stuff to go onto a 110mm boss adaptor (not
strap on - proper adaptor with several 40mm inlets) and is this joint
solvent welded or should I be looking for a coupling piece of some sort?

At that point I'd use a dismantable joint assuming you have access. So you
can get at and open the pipe at that point, again for cleaning blockage
removal.

Aye - shouldn't be a problem - kitchen run is dead straight until it hits
the wall under the shower room basin, and of course, the junction to the
110mm.

The 110mm junction will already have access - the top cap will be removable
for poking drain wire round the 90 deg bend under the floor (can be poked
from the nearby manhole too). This pipe is grey water only - I asked the
builder to make it 110 as several drains are running into it and it's
hidden behind an under-basin cupboard anyway.

Rather than use an elbow where it comes out under the kitchen sink and up,
I'll use a tee with a screw on blanking plug on the horizontal dead-end -
this will give me simple and straight-line access to poke a rod right along
its length towards the 110.

I'm likely to have a waste disposal unit, so I'm allowing for the fact the
poor pipe will have all manner of gunk stuffed through it.

Fall *could* be easily upto 300mm in about 3000mm (1/10) but I'll use a bit
less, maybe 1/20

Is 40mm enough for a whole kitchen? We have a long 40mm from the kitchen
and it only just copes with sink and washing machine and has blocked once
but then one bit only just has enough fall. The Grand Scheme Of Things has
this replaced with 50mm...


No - I hadn't thought of going right upto 50mm - I must admit I thought 40mm
was being generous. But as you've mentioned it I'll have look at that.

Only the run to the bath will be tortuous with limited fall (about 5m and
height is whatever a bath trap disgourges at down to as close to the floor
level as I can get) with 2 90deg bends - but that pipe will join separately
into the 110mm and bath water should have less propensity to block pipes
(hair notwithstanding).

Cheers

Tim

On Mon, 26 Jan 2009 08:39:15 +0000, Tim S wrote:

Potentially all accessible (inside a long airing cupboard)

Hum, so any leak, even minor, would not be welcomed. Waste water on clean
airing clothes, towels, bedding etc?

This pipe is grey water only - I asked the builder to make it 110 as
several drains are running into it

Very wise. Though kitchen sink waste is anything but grey IMHO, and the
grey from a washing machine is full of the filler to bulk up the powders,
it was mainly that which blocked our long run...

I'll use a tee with a screw on blanking plug on the horizontal dead-end
- this will give me simple and straight-line access to poke a rod right
along its length towards the 110.

Yep, good move. See if you can get a cap with a locking screw. Thermal
expansion/contraction might make something just screwed on work itself
loose over time.

I'm likely to have a waste disposal unit, so I'm allowing for the fact
the poor pipe will have all manner of gunk stuffed through it.

See, not grey. B-)

Fall *could* be easily upto 300mm in about 3000mm (1/10) but I'll use a
bit less, maybe 1/20

I'd have to go away and look up what is recomended. 1:10 has a gut feeling
of too steep. Too steep the water runs away leaving bits behind, too
shallow the water doesn't flow fast enough to caryy the bits. I'd expect
the WDU instructions to say what fall the outlet should have.

No - I hadn't thought of going right upto 50mm - I must admit I thought
40mm was being generous.

Depends what is discharging into it just a sink would be fine but sink and
something else washing machine and/or dishwasher and it starts to back up
if both discharge at the same time. OK you could try not to pull the sink
plug when the machines are pumping but you can't control the machines
(they could pump together) and sods law will say both will pump just as
you've pulled the plug and left the kitchen...

--
Cheers
Dave.

In article ,
Tim S writes:

Only the run to the bath will be tortuous with limited fall (about 5m and
height is whatever a bath trap disgourges at down to as close to the floor
level as I can get) with 2 90deg bends - but that pipe will join separately
into the 110mm and bath water should have less propensity to block pipes
(hair notwithstanding).

In this case, I would suggest not running it directly into
the 110mm, but if you can, have it turn a corner and run down
parallel for a metre or two. That fall will generate suction to
overcome the long low drop section and speed up bath emptying.
Actually, it works really well if you reduce the pipework to
32mm for the fall, as it's more likely to completely fill with
a plug of water to generate the suction.

I ended up with a situation like this once (not really by
design, just by making use of what happened to be there before),
and it works really well. You need an AAV U-trap on the bath
and I put a removable rodding cap at the top of the 32mm
vertical drop in case it ever blocked at the pipe narrowing,
but it never has. When you pull the plug out, you can see the
water starts trickling out very unenthusiastically along the
long run, and then the suction kicks in when enough of it
starts going down the vertical section, and it starts emptying
out much faster.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Andrew Gabriel coughed up some electrons that declared:

In this case, I would suggest not running it directly into
the 110mm, but if you can, have it turn a corner and run down
parallel for a metre or two. That fall will generate suction to
overcome the long low drop section and speed up bath emptying.
Actually, it works really well if you reduce the pipework to
32mm for the fall, as it's more likely to completely fill with
a plug of water to generate the suction.

Interesting idea Andrew. Wouldn't it suck the trap out though?

I wouldn't be able to do it though - I've only got about 10cm of fall
total

Cheers

Tim

On Mon, 26 Jan 2009 18:20:08 +0000, Tim S wrote:

Andrew Gabriel coughed up some electrons that declared:

In this case, I would suggest not running it directly into
the 110mm, but if you can, have it turn a corner and run down
parallel for a metre or two. That fall will generate suction to
overcome the long low drop section and speed up bath emptying.
Actually, it works really well if you reduce the pipework to
32mm for the fall, as it's more likely to completely fill with
a plug of water to generate the suction.

Interesting idea Andrew. Wouldn't it suck the trap out though?

I've used HepVO - no water so no siphonage, no drying out, no need to raise
a shower to get a trap under it...

http://www.a-s-m.com/hepvosanitarywastevalve.html

I wouldn't be able to do it though - I've only got about 10cm of fall
total

Cheers

Tim


--
Peter.
You don't understand Newton's Third Law of Motion?
It's not rocket science, you know.

PeterC coughed up some electrons that declared:


http://www.a-s-m.com/hepvosanitarywastevalve.html


In a situation where you might need an air admittance valve as well, these
would certainly kill two birds.

Cheers Peter - I'll keep this tucked away - I have possibly one place at
least were these would make a lot of sense.

Ta

Tim

In article ,
Tim S writes:
Andrew Gabriel coughed up some electrons that declared:

In this case, I would suggest not running it directly into
the 110mm, but if you can, have it turn a corner and run down
parallel for a metre or two. That fall will generate suction to
overcome the long low drop section and speed up bath emptying.
Actually, it works really well if you reduce the pipework to
32mm for the fall, as it's more likely to completely fill with
a plug of water to generate the suction.

Interesting idea Andrew. Wouldn't it suck the trap out though?

Hence the reference to the AAV U-trap (in the bit you trimmed off;-)

I wouldn't be able to do it though - I've only got about 10cm of fall
total

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]