Small Bathroom - how to re-route the plumbing?!

ST1991

Hi All - we are FINALLY looking at getting our bathroom done, and have looked at the suite and furniture we we want and drafted up a basic plan in roomstyler.
Before we get a few quotes for fitting/plumbing, i wanted to check something.

It's a small bathroom, so to make the most of the floorspace we are hoping to move the toilet away from the external wall, to an internal wall.

Does anyone have any guidance on moving the toilet in regards to plumbing?
It will be moved less than 2 metres in distance - but the soil pipe comes directly through the exterior wall and straight into the toilet at the moment, so when moved it will have to run straight.

Is it OK to run it straight for 2 metres before it falls at the front of our house?

I've included a rough picture below of where it will be moved to, if this helps. Red is where it is at the moment, and blue is where we will be hopefully moving it to.
For reference the room is 2.9M long x 1.7M wide. The 'top' wall which is longest and straight is a party wall as we are mid-terrace. Other walls are internal, and the 'bottom' wall is a stud wall.



P.S our soil stack joins on with next door and then runs down the front of our house (and our walls are over a foot thick) so we don't want to move where it runs into the house if possible!

Doozergirl

It only needs a slight fall so it is possible to put it where you want where it will ostensibly look straight. However, you are going to have 2m of 4 inch pipe to look at, box in or hide. Do you have anything else planned for that wall between the loo and where the soil pipe exits? it will need to be designed to sit over the pipe.

EssexExile

What's the other side of the wall where the new loo will go? Would it be easier to put the pipe through the wall & hide the 2m run in that room?

ST1991

Doozergirl wrote: »

It only needs a slight fall so it is possible to put it where you want where it will ostensibly look straight. However, you are going to have 2m of 4 inch pipe to look at, box in or hide. Do you have anything else planned for that wall between the loo and where the soil pipe exits? it will need to be designed to sit over the pipe.

Thanks for the quick reply!
The plan is the have a sink/wc vanity unti along that wall. There will then be a short (1500) L shaped bath along the exterior wall to leave some room for the pipe to run along the bottom of the vanity units, under the clearance from the bath and out the wall.
Happy to lose some cupboard space at the bottom of the vanity units to fit the pipe - i just worried about somehow having a fall when it will run completely horizontally to the current exit in the wall?
Unless i build the toilet up on a pedestal? lol

ST1991

EssexExile wrote: »

What's the other side of the wall where the new loo will go? Would it be easier to put the pipe through the wall & hide the 2m run in that room?

That wall is a stud, so we could potentially actually run it 'inside' the wall.
The other room is a bedroom - so would rather not have it running through there!

I'm not too worried about concealing the pipe - I just don't want to run it horizontally if it will cause issues for flushing/blocking.

Doozergirl

It won’t be running horizontally. It will look it, but it only needs a few degrees of fall and gravity will do the job. The connection outside onto the main soil pipe can be altered, if necessary.

If you put a back-to-wall loo with a concealed cistern into a cabinet as well you could entirely conceal the whole run to the external wall.

ST1991

Doozergirl wrote: »

It won’t be running horizontally. It will look it, but it only needs a few degrees of fall and gravity will do the job. The connection outside onto the main soil pipe can be altered, if necessary.

If you put a back-to-wall loo with a concealed cistern into a cabinet as well you could entirely conceal the whole run to the external wall.

That really helps clear it up, thank-you
I had visions of spending £3K + on a bathroom suite and it just flooding the bathroom one day because i'd overlooked something!
We are planning on a back to wall toilet with concealed cistern exactly like you have said - built into the vanity/cabinet unit. They have some really nice ones on those websites with the 2 suspiciously similar sounding names (VP) that we've got our eye on.

Woohoo! Thanks for all your help

martinsurrey

Doozergirl wrote: »

If you put a back-to-wall loo with a concealed cistern into a cabinet as well you could entirely conceal the whole run to the external wall.

I've done something simlar

something like this

(not endorsing the supplier, but the style!)

Then the bath would be about 2.2m long, which is what OP is looking for.

OP you need about a 1 in 40 drop on the soil pipe so over 2m you need 5 cm, sit the toilet on floorboards + tiles + the natural height the soil pipe exits the WC and you'll have enough space for the drop one way or the other (drop the floor boards under the bath if you need too).

ST1991

martinsurrey wrote: »

I've done something simlar

something like this

(not endorsing the supplier, but the style!)

Then the bath would be about 2.2m long, which is what OP is looking for.

OP you need about a 1 in 40 drop on the soil pipe so over 2m you need 5 cm, sit the toilet on floorboards + tiles + the natural height the soil pipe exits the WC and you'll have enough space for the drop one way or the other (drop the floor boards under the bath if you need too).

Yep, this is the kind of thing we are looking at - with the toilet and sink the other way around.

Thanks again. I had drawn up my dream bathroom (well... about as dreamy as it can get for its size) but then fell short when i actually stopped and thought about plumbing - so i am really pleased that i can still stick with the design we want!

The bath will be going long-ways along the wall with the window, but should be short enough to leave space at that end for the soil pipe. As our bathroom is narrow (roughly 1.6M wide) we're not really losing much space between a 1500 and 1600 long bath - just a bit more 'breathing space'.

Now just to find out how much the plumbing/fitting will cost...! (Husband can tile, thank god!)

EachPenny

You need to check carefully that the new toilet pan has the outlet as high, if not higher, than the existing one. The height of the outlet above the floor is not something which has been consistent through the years so you might find yourself dealing with a difference in outlet level as well as needing to find some 'fall' over the 2m run.

The other (potentially major) issue is that the hole through the outside wall is probably aligned with the centreline of the toilet (as indicated by the red lines on your plan). The new 2m pipe should be attached as close as possible to the internal wall.

That means if you do not want to create a new hole through the external wall then you'll need to use a pair of 90 degree bends with a short length of pipe between them to make up for the difference in alignment between the internal wall and the hole outside.

Two bends and a flat fall is asking for trouble with blockages.

Personally I'd look at either making a new hole through the external wall, or else opening the existing hole downwards (if possible) in order to give you more fall to play with.

Failing that, you should have some kind of access point on the pipe (located behind an easy to remove section of boxing-in) so it is possible to clear any blockages without having to take everything apart.