Any plumbers around - quick question

Location
Rammy
further to my topic asking about removing and fitting a toilet, I was wanting to fit a sink for hand washing into the downstairs toilet that I'm looking at replacing, however the only drainage from the area is the waste pipe from the downstairs loo, and this is concreted in (concrete floor etc)

there is no method of running the waste pipe from the sink out to join the kitchen drain that I can see, it would need to cross the room completely, this room forms a corridor.

I had thought, since it's only a small sink for hand washing that it might be possible to just drain the sink into the pipe connecting cistern and toilet pan, as such the small amount of water used to wash hands drains through the pipes into the toilet itself by connecting it in using a wye joint similar to this:
234727943.jpg


so, to my question:

is it ok to do this (I know it's possible as the pipes will physically fit together) what I don't know is any detrimental effects this will have on the toilet's flushing ability or what effect flushing the toilet may have on the sink.

Thanks.
 

subaqua

What’s the point
Location
Leytonstone
its possible ( but unlikley) that flushing the toilet will empty the water out of the trap under the sink from the vacuum effect. one soultion is to fit a dry trap " Fanny trap" or put an Air admittance valve ( durgo) on a tee between the sink trap and the entry into the stack.
 
I'm not a plumber; but, I've done a lot of D.I.Y.

If you can fit on of these between the pan and the soil pipe in the ground you can solvent weld the sink drain into one of the spigots, remembering to cut out the spigot first; if you don't do that the water doesn't run away form the sink. :whistle:

It should have no effect on the toilet flushing and it's extremely unlikely to have an effect on the sink waste. The only thing that could happen is siphoning the sink waste trap out, which if it happens, you should be able to cure by making a deeper trap than normal from fittings rather than using the normal per-formed purchased trap.
 
OP
Black Sheep
Location
Rammy
I'm not plumbing the sink drain to the stack as that's underground, embedded in concrete and made from either ceramic or cast metal.

would an AAV between U bend and joining the pipe from the cistern work?
 
further to my topic asking about removing and fitting a toilet, I was wanting to fit a sink for hand washing into the downstairs toilet that I'm looking at replacing, however the only drainage from the area is the waste pipe from the downstairs loo, and this is concreted in (concrete floor etc)

there is no method of running the waste pipe from the sink out to join the kitchen drain that I can see, it would need to cross the room completely, this room forms a corridor.

I had thought, since it's only a small sink for hand washing that it might be possible to just drain the sink into the pipe connecting cistern and toilet pan, as such the small amount of water used to wash hands drains through the pipes into the toilet itself by connecting it in using a wye joint similar to this:
234727943.jpg


so, to my question:

is it ok to do this (I know it's possible as the pipes will physically fit together) what I don't know is any detrimental effects this will have on the toilet's flushing ability or what effect flushing the toilet may have on the sink.

Thanks.
Basin, you mean basin. :rollseyes:

Where does the lavvy waste go after the concrete floor? Can we presume it runs into a stack/stench pipe on the outside of the building?

The trouble with running it into the cistern/pan connector pipe is that the flush channels within the pan will - sooner or later - clog up with hair, toothpaste sludge and all the rest that usually disappears down the plughole. With no way of cleaning it out. It'll deffo be in contravention of the building regs - though I couldn't tell you which paragraph/section.
 
OP
Black Sheep
Location
Rammy
I've no idea where the lavvy waste goes, the entire back garden turns out to be concrete when you take the skim of earth and pebbles away!

there is no stack on the outside of the building, I believe this toilet to be the original outdoor toilet that has now been enclosed by extending the house / attaching the out buildings to the main house.

it will be a downstairs extra toilet so the basin will be just a small one for hand-rinsing, the main bathroom will remain upstairs so only water and soap to be going down the drain.

just thinking for future use a downstairs / extra toilet might come in handy when we have a family / can't be bothered to go upstairs from the garden etc - if I can't fit a sink then the wife wants it removed (although the next room has a sink in it, just the opposite side of the room)
 
Sorry I misunderstood your original post I had no idea you meant the connect the basin drain into the down pipe from the cistern to the pan, as Mickle points out this is a big no no and will eventually lead to blocking flush channels.

from reading your previous post - the Waste Soil Pipe is set directly in the floor. Most toilet now have a connection directly out the back and you need to buy one of these to get it from out the back to the floor. You may be able to get one with a solvent weld connection for the basin drain or get a strap-on connection like this or you may be able to fit a manifold arrangement like this.

The connection needs to be made to the 110mm Soil pipe.
 
OP
Black Sheep
Location
Rammy
As I said before, as I'll only be putting water and a bit of liquid soap (the wife is a nurse and has a thing against traditional soap) will it actually block the flush channels any quicker than the toilet on its own?
 
Hello Black Sheep, I believe that you would live to regret the decision to connect into the pipe between cistern and pan, especially if you plan to live there for a while.

The connection to the basin drain should be via soil waste pipe. As I mentioned above the new pan you buy will have the waste straight out the back so you need to fit a plastic adapter pipe anyway and you can make the basin connection to it, using the fittings I had the links to.
 

subaqua

What’s the point
Location
Leytonstone
I mis read the OP . big no no connecting into the cistern to bowl pipe. i thought you meant connecting into the stack.

it will clog up remarkably quick- soap loves a little crevice and will collect there blocking the pan flush.
 
OP
Black Sheep
Location
Rammy

I mis read the OP . big no no connecting into the cistern to bowl pipe. i thought you meant connecting into the stack.

it will clog up remarkably quick- soap loves a little crevice and will collect there blocking the pan flush.

Thanks for being specific about the soap residue,

and thank you to all who've posted, I really appreciate it.

Hello Black Sheep, I believe that you would live to regret the decision to connect into the pipe between cistern and pan, especially if you plan to live there for a while.

The connection to the basin drain should be via soil waste pipe. As I mentioned above the new pan you buy will have the waste straight out the back so you need to fit a plastic adapter pipe anyway and you can make the basin connection to it, using the fittings I had the links to.

where would you say was the best position to join into the plastic adapter?
might be best to use the manifold that was suggested earlier, could this go straight into the the soil pipe with the adaptor pipe into that?
 

Mark Grant

Acting Captain of The St Annes Jombulance.
Location
Hanworth, Middx.
Assuming you have removed your S trap WC and are replacincing it with a P trap wc, you will be using a 90 degree quick fit adapter. These are available with a boss on the top which could possibly take your waste pipe.
This one is a Mc Alpine.
WC-CON8V_5.jpg
 
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