New professionally installed walk in shower. After being left unused
for a period on running the shower the shower tray fills up with
scummy bubbly water and gets practically to the point of escaping over
the ledge where you walk in. At that point we chicken out and pull out
the big chrome insert that covers the shower drain, and all the water
dissappears in a trice. Putting the chrome cover back in/on and the
water thereafter flows away freely untill the shower has been stopped
for a period (an hour or two?). 

I can't find the exact shower waste fitting on the web but it's a
shallow chriomium plated plastic dome about 5" across with what looks
like a 3 sausage-segment air vent holes in the top, about 2cms P.C.D.,
waste shower water is intended to drain away under & around it's
perimeter. 'Cept it doesn't without that bit of persuasion. It seems
it might be at least similar to something called a "Fastflow" waste.

The walk in shower replaced the existing standard bath, but the waste
is perversely at the walk in end and the pipe had to be extended I'd
say the run to the soil stack is a bit over 3 metres and the fall is
less than the depth of the joists with one right angle bend. However
with the domed chrome insert removed it drains OK. If anything has to
be changed under the floor it can't be done, it's all sealed up :-(

I wasn't aware that these shower wastes were such a complicated affair
with concentric cups and sleaves. Exactly what it is all supposed to
do defeats me.  Anybody come across anything like this before P.S.E. ?

DG

On Tue, 30 Aug 2005 19:33:49 +0100, Derek ^
 wrote:


>
>New professionally installed walk in shower. After being left unused
>for a period on running the shower the shower tray fills up with
>scummy bubbly water and gets practically to the point of escaping over
>the ledge where you walk in. At that point we chicken out and pull out
>the big chrome insert that covers the shower drain, and all the water
>dissappears in a trice. Putting the chrome cover back in/on and the
>water thereafter flows away freely untill the shower has been stopped
>for a period (an hour or two?). 
>
>I can't find the exact shower waste fitting on the web but it's a
>shallow chriomium plated plastic dome about 5" across with what looks
>like a 3 sausage-segment air vent holes in the top, about 2cms P.C.D.,
>waste shower water is intended to drain away under & around it's
>perimeter. 'Cept it doesn't without that bit of persuasion. It seems
>it might be at least similar to something called a "Fastflow" waste.
>
>The walk in shower replaced the existing standard bath, but the waste
>is perversely at the walk in end and the pipe had to be extended I'd
>say the run to the soil stack is a bit over 3 metres and the fall is
>less than the depth of the joists with one right angle bend. However
>with the domed chrome insert removed it drains OK. If anything has to
>be changed under the floor it can't be done, it's all sealed up :-(
>
>I wasn't aware that these shower wastes were such a complicated affair
>with concentric cups and sleaves. Exactly what it is all supposed to
>do defeats me.  Anybody come across anything like this before P.S.E. ?
>
>DG



I suspect that the fall on the waste pipe is inadequate for the length
and diameter, given the waste fitting.  

I remember reading somewhere (but can't find the reference now) that
some types of "mushroom" shower drain can capture a bubble of air but
that this goes through to the drain if the flow is fast enough.
Otherwise, the bubble causes the flow to remain restricted.   Lifting
off the cap effectively removes this and allows full flow through the
trap.

The only two components that can be involved are the waste fitting and
the pipe, but as you say, they are sealed down.

Did the installer do the whole job?   If so, or anyway, I would get
him back to fix it.   If it does involve ripping the lot up, then I
would expect him to take the cost.   He should have done the job
properly in the first place.




-- 

..andy

To email, substitute .nospam with .gl

We have a similar experience. As Andy has said it seems to be related 
to the design of the drain and apart from regularly dehairing it, there 
seems to be no satisfactory answer. I've considered drilling a hole in 
the top to see what this does, but I too would like to understand it. In 
our case, the run to the main drain is <1M of 40mm pipe, so it's not the 
drain blocking. The problem does seem to come and go, but keeping the 
trap clear does help.

	Regards
	Capitol

In message , Derek ^ 
 writes

>
>New professionally installed walk in shower. After being left unused
>for a period on running the shower the shower tray fills up with
>scummy bubbly water and gets practically to the point of escaping over
>the ledge where you walk in. At that point we chicken out and pull out
>the big chrome insert that covers the shower drain, and all the water
>dissappears in a trice. Putting the chrome cover back in/on and the
>water thereafter flows away freely untill the shower has been stopped
>for a period (an hour or two?).
>


If you run the shower without the chrome insert when the area is empty, 
does the water drain away OK - if so, the problem is with the chrome 
thing, so I would probably replace it with a normal one.

If not, it's in the pipes. It's possible that the water drains when you 
take the chrome thing out, because the reduced resistance allows the 
pressure of the water to create a syphon effect, (a bit like a toilet). 
I have to do this with my shower because the drain pipes do not have 
enough fall, (It's a long story, and will be fixed in the near future).



>I can't find the exact shower waste fitting on the web but it's a
>shallow chriomium plated plastic dome about 5" across with what looks
>like a 3 sausage-segment air vent holes in the top, about 2cms P.C.D.,
>waste shower water is intended to drain away under & around it's
>perimeter. 'Cept it doesn't without that bit of persuasion. It seems
>it might be at least similar to something called a "Fastflow" waste.
>
>The walk in shower replaced the existing standard bath, but the waste
>is perversely at the walk in end and the pipe had to be extended I'd
>say the run to the soil stack is a bit over 3 metres and the fall is
>less than the depth of the joists with one right angle bend.


> However
>with the domed chrome insert removed it drains OK.


If this is the case, I would just dump it and not worry how it works <g>


> If anything has to
>be changed under the floor it can't be done, it's all sealed up :-(
>
>I wasn't aware that these shower wastes were such a complicated affair
>with concentric cups and sleaves. Exactly what it is all supposed to
>do defeats me.  Anybody come across anything like this before P.S.E. ?
>
>DG
>


-- 
Richard Faulkner

Capitol wrote:


> 
>     We have a similar experience. As Andy has said it seems to be 
> related to the design of the drain and apart from regularly dehairing 
> it, there seems to be no satisfactory answer. I've considered drilling a 
> hole in the top to see what this does, but I too would like to 
> understand it. In our case, the run to the main drain is <1M of 40mm 
> pipe, so it's not the drain blocking. The problem does seem to come and 
> go, but keeping the trap clear does help.


The chrome thing in my one has a screw height adjustment on its 
underside. Hence you can tweak the height above the surrounding tray. I 
found my one need raising a mm or two to get suitable flow through it. 
Might be worth investigating if yours has the same.

-- 
Cheers,

John.

/=================================================================\
|          Internode Ltd -  http://www.internode.co.uk            |
|-----------------------------------------------------------------|
|        John Rumm - john(at)internode(dot)co(dot)uk              |
\=================================================================/

On Tue, 30 Aug 2005 20:30:07 +0100, Andy Hall <andyh@hall.nospam>
wrote:


>
>I suspect that the fall on the waste pipe is inadequate for the length
>and diameter, given the waste fitting.  
>
>I remember reading somewhere (but can't find the reference now) that
>some types of "mushroom" shower drain can capture a bubble of air but
>that this goes through to the drain if the flow is fast enough.
>Otherwise, the bubble causes the flow to remain restricted.   Lifting
>off the cap effectively removes this and allows full flow through the
>trap.
>
>The only two components that can be involved are the waste fitting and
>the pipe, but as you say, they are sealed down.


Spoken to the fitter, he tells me there is a HepVo valve under the
floor close to the shower. Given that the fall is not great I'm
wondering if the "head", which may only be 4-5 cms, is enough to open
the valve fully until there's a surge caused by lifting the chrome
dome. If left to it's own devices with the shower shut off the water
does run away eventuallty.

I'm homing in on this as an explanation.

On the HepVo website the examples all illustrate a substantial head ,
even with a horizontal installation. 

http://www.hepworthplumbing.co.uk/hepv2.htm

Unfortunately I can't seem to open their PDF design guide. :(

Do these things have a correct and incorrect orientation the fitter
could have got wrong? I've never seen/handled one myself..


>
>Did the installer do the whole job?


Yes. 18 years in the bathroom business.


> If so, or anyway, I would get him back to fix it. 


Absolutely. SWMBO *doesn't like* paddling in a whole load of scummy
water when she's showering.  :((


>If it does involve ripping the lot up, then I would expect him to take the cost.
>He should have done the job properly in the first place.


DG

On Wed, 31 Aug 2005 13:13:33 +0100, Derek ^
 wrote:


>On Tue, 30 Aug 2005 20:30:07 +0100, Andy Hall <andyh@hall.nospam>
>wrote:
>
>>
>>I suspect that the fall on the waste pipe is inadequate for the length
>>and diameter, given the waste fitting.  
>>
>>I remember reading somewhere (but can't find the reference now) that
>>some types of "mushroom" shower drain can capture a bubble of air but
>>that this goes through to the drain if the flow is fast enough.
>>Otherwise, the bubble causes the flow to remain restricted.   Lifting
>>off the cap effectively removes this and allows full flow through the
>>trap.
>>
>>The only two components that can be involved are the waste fitting and
>>the pipe, but as you say, they are sealed down.
>
>Spoken to the fitter, he tells me there is a HepVo valve under the
>floor close to the shower. Given that the fall is not great I'm
>wondering if the "head", which may only be 4-5 cms, is enough to open
>the valve fully until there's a surge caused by lifting the chrome
>dome. If left to it's own devices with the shower shut off the water
>does run away eventuallty.
>
>I'm homing in on this as an explanation.
>
>On the HepVo website the examples all illustrate a substantial head ,
>even with a horizontal installation. 
>
>http://www.hepworthplumbing.co.uk/hepv2.htm
>
>Unfortunately I can't seem to open their PDF design guide. :(


It was OK for me, but most of it is on the web pages anyway by
clicking through the tabs.    They make one version intended for
horizontal use that has a fitment to go straight onto the waste
fitting, and is then angled at 87.5 degrees (normal slope).



>
>Do these things have a correct and incorrect orientation the fitter
>could have got wrong? I've never seen/handled one myself..


Yes they do.  If he had it the wrong way round it wouldn't work at all
in normal use but will eventually open at 500mm head.   If the trap
weren't working properly, you wouldn't be able to get correct results
by removing the cap of the waste.


>
>>
>>Did the installer do the whole job?
>
>Yes. 18 years in the bathroom business.
>


Then he ought to know what works I would have thought.   Is it the
first time he has fitted this waste type I wonder.....


>> If so, or anyway, I would get him back to fix it. 
>
>Absolutely. SWMBO *doesn't like* paddling in a whole load of scummy
>water when she's showering.  :((
>
>>If it does involve ripping the lot up, then I would expect him to take the cost.
>>He should have done the job properly in the first place.
>
>DG




-- 

..andy

To email, substitute .nospam with .gl

On this drainage problem, I noticed in a shower today that the 
large(100mm?) chrome drain cover had a couple of holes in it, 3mm and 
7mm diameter, about 25mm or so in from the edge.

	Regards
	Capitol