Very slow draining of bath, how to cure?

[usenet]

I have a problem with improving the rate at which our newly installed bath drains. The old one was just as bad, the difficulty is the poor design of the original installation which I am rather stuck with.

The bath is in a flat and is positioned about two or three meters from the main service duct where the sewage downpipe is. The waste pipe from the bath runs essentially horizontally from the trap under the bath across to the downpipe. Not surprisingly, especially towards the end, it drains very slowly. It's impossible to get at the connection of the waste into the downpipe as it's inside a brick built service duct, all you can get at is a 40mm 'socket' where it pokes through a hole in the brickwork.

Can anyone suggest any clever ways to improve this? It'll be quite difficult to do anything much about the drop in the pipe although there is currently access from below (the kitchen) as the leaks from the old bath and drain have caused a bit of the kitchen ceiling to collapse. However even if we took the pipe down through the ceiling I can't see how it could then be routed to the service duct without major building work. I suppose it could join the waste pipe from the kitchen sink but how would you prevent water 'welling up' into the sink?

Is pumped waste possible? Are one-way valves for waste pipe available?

The washbasin waste pipe is even worse, it has a near horizontal run of four meters or so and the same difficulties of improving the drop apply. It could run into the bath waste and gain some drop that way but, again, how do you stop it coming up into the bath?

[Owain]

wrote | The bath is in a flat and is positioned about two or three meters | from the main service duct where the sewage downpipe is. The | waste pipe from the bath runs essentially horizontally from the | trap under the bath across to the downpipe. Not surprisingly, | especially towards the end, it drains very slowly. It's impossible | to get at the connection of the waste into the downpipe as it's | inside a brick built service duct, all you can get at is a 40mm | 'socket' where it pokes through a hole in the brickwork. | Can anyone suggest any clever ways to improve this?

It's not clear if the bath outlet runs within the floor void or if it *has* to, but if you could elevate the bath by a couple of inches (say by using a couple of floor joist -like bits of wood on their sides as planks under the bath feet) that might give you enough more fall on the pipe.

Even if the pipe has to stay within the floor void, elevating the bath a bit should give an increase in flow because of the increased 'head', thus encouraging most of the water out a bit quicker and reducing the amount that sediments/stagnates in the flat bit of pipe.

Owain

[BigWallop]

What size is the waste connection at the outlet for the kitchen system ? If you have a 50mm out flow from the kitchen, then you can combine both the bathroom and kitchen to the one outlet, and then cap the old bathroom waste at the service duct. But this can only be done if the kitchen out flow is

50mm at the outlet to the main stack.

[David W.E. Roberts]

The only thing that immediately occurs is to use a larger bore of pipe for as much of the run as possible. i.e. have large bore pipe from the sink and/or bath right up to the 40mm socket in the trunking. I think that this would ease the flow of the water by reducing the resistance along most of the pipe; having said that I don't think modern baths drain well at all. ISTR that baths in old houses (and old hotels) used to drain much faster. I have guessed that this is due to larger bore lead waste pipes in old installations.

Other option is to raise the bath with a step next to it to make getting in and out easy (opposite of a sunken bath). This would give you a better head of water/drop over the length of the pipe run. You could also raise the basin by putting it on a raised base - but this might look wierd :-) Think of it as a part raised floor in the bathroom.

Combine the two - have a large bore pipe under the raised bath.

Our main bath drains slowly, and the waste just runs the length of the bath (taps away from the outside wall) so I think you will be lucky to get reasonably fast draining with anything but the shortest run.

Having a rambling day today :-)

Dave R

[usenet]

Elevating the bath isn't a very practical solution from the appearance point of view though as the bath panels sort of fix the bath's height.

The existing waste pipe runs above floor level, it would be a real pig to get it into the void as it would have to go through several joists.

The real problem though is the impossibility of moving the position of the waste where it goes into the service duct. That's why I was thinking of taking the waste down to the kitchen below, that gives lots of gradient - much too much really - but that's an issue one can deal with isn't it?

[usenet]

Why exactly? Is that a building regulations thing? If do it's something I haven't spotted.

[Andrew Mawson]

Chris, are you absolutely sure that the entry into the foul downpipe is truly clear? I had a similar problem in one of my flats that I eventually traced to 'rusticles' on the inside of the cast iron down pipe catching a hairball. Nothing was visable in the branch pipe until it was stripped out to a bare socket when with a torch the problem was obvious and easily cured.

Another possibility is something I found in my own house. Basin waste pipe joins main pipe from bath to downpipe at a 'Tee' which had been installed with the 'swept' branch flowing towards the basin rather than towards the outlet (yes >I< must have done it many years ago when I changed the bath -

1985 I think!). Turning the Tee made a vast difference.

Andrew Mawson

[gaz]

I had a similar problem after changing my bath. After looking at the 'plug hole' I noticed that the old one had a sort of cast grid while the new one was just drilled holes. By the time I noticed this I had already thrown the old one out, and could not find the same type in my local suppliers. I eased it slightly by cleaning up the holes and putting a sort of 'countersink' on them but it is still not as good as the old one.

While on the subject, my new toilet does not flush a s well as the old one either. And if I turn the taps on too quickly on the hand basin the water streams out of the other side. I have decided that the older ones looked so functional because they were. The newer ones look pretty because they are not so functional.

>

[usenet]

Pretty sure as the loo works perfectly and other peoples' waste goes down the same downpipe quite successfully.

No tees involved. It's *possible* that the point at which the 40mm waste goes into the downpipe isn't perfect but there's little I can do about that as it's very inaccessible.

[Mike P]

Get rid of the bath & install a shower cubicle on a stand with an extra step if needed to elevate it, I did this about 15 yrs ago and we have never missed the bath. A shower is healthier than wallowing in your own soapy water and it's cheaper. What about when you break you leg you ask, 'bin bag'.

Mike P.

[Mike P]

Get rid of the bath & install a shower cubicle on a stand with an extra step if needed to elevate it, I did this about 15 yrs ago and we have never missed the bath since. A shower is healthier than wallowing in your own soapy water and it's cheaper. What about when you break you leg you ask, 'bin bag'.

Mike P.

[BigWallop]

The 50mm would be the minimum you'd need to take two or three appliances emptying at the same time. If the bath and hand wash basin are both being evacuated at once, and from that raised position, you'd need at least 50mm pipework to take the flow required, or you're back in the same boat with a slow running waste system.

I was always told that anyone can bring water in, but it takes a good plumber to take it all away again safely and fast enough.

[N. Thornton]

If the old one was as bad, you might have grease in the pipework making it worse (causetic soda and caution) or a mchanical partial block (bendy springy thing)

I didnt follow the setup entirely, but can you parallel your 2 waste pipes? If you can that would speed it up to some extent.

Finally pumped waste is simple enough, but AFAIK you'd have to either make the sensor and control circuit yourself, or else just use a manually operated switch for the pump, preferably a push switch with built in timer, as used in communal hallways etc.

Regards, NT

[usenet]

I think it's more down to the simple lack of gradient.

Not really much use as the washbasin one is much higher than the bath so won't help the bath wast at all. There's no way to add extra waste pipes because the downpipe is inaccessible in the service duct.

That could be the way to go, where does one get pumps, the only ones I've seen are Saniflow ones which are too big for what I want, I want a 40mm only pump.

[usenet]

My daughter just did exactly the opposite, she always showered until recently but then discovered the luxury of a decent bath and wanted the bath in the flat improved. That's why we now have a new bath there.

... another danger of showers! :-)

[dmc]

Ah, but you can't fall asleep in the shower while reading the screwfix catalogue can you?

Darren - or is that just me?

[Owain]

"Mike P" wrote | A shower is healthier than wallowing in your own soapy | water and it's cheaper.

But it's so difficult to hear the radio above the noise of the water, and the spray splashes all over the place, gets the chocolate and library-book wet, and dilutes the alcohol.

Owain

[Mike P]

Ah, but you can't fall asleep in the shower while reading the screwfix

You won't be able to turn the pages if you do fall asleep, cos there stuck together. Nor can you order when you've drowned! Mike P.

[Tony Williams]

Could you solve the gradient problem by lifting the bath onto blocks, and put skirting panels around it?

[usenet]

That was suggested right at the beginning of this thread! :-)