Help and advice on toilet waste pipe location. Pics included

[Kristoff28]

Howdi all

Havent been on for a while but have a new project on the go and could do
with some plumbing advice from the pro's.

I'm fitting a new bathroom and want to plumb the toilet and sink waste pipes under the floor as i hate boxed in pipes etc. I like everything
hidden with nice clean lines.

I aslo want to swap the toilet and sink in opposite positions to maximise
space .

Some pics below that will explain a bit more detail

Bathroom stripped out. You can see where the toilet was originally looking
at the lines on the floor

Waste pipes going to outside wall

Outside view of the pipes

This is the new layout that i want

The toilet base and sink pedestal are flush fitting to the wall so there is no room for passing waste pipes etc hence why i want to sink everything into the floor and what i want to know is, is this DO able ???
Luckily the joists underneath run the same way as the toilet waste pipe
so there will be no joist cutting involved, just running along side them.

Also been scratching my head on cutting another hole in the outside wall
as i will need to drop everything down a foot or so but thought could i not
come back up to the original pipe under the bath using a flexi pipe or
u-bend but then thought this would cause blockage problems ???

Has anyone else done this ???

Any help and info would be greatly appreciated.

Got the tilers coming in next monday so need to get my skates on haha.

cheers

Kris

 

[JPC]

if you have the depth in the joist area then you could drop the pipes below and exit lower down, which will require a new joint on the outside soil pipe.

The fall required i seem to remeber is around 20mm per meter

the other option is to exit at the rear of the toilet and rear of the basin, connect the basin to the soil pipe outside, then come round the corner, having moved your rain water downpipe over by a foot or so and fitting a large water but with an overflow in the soil pipe

Does the rain water pipe go into the ground or shoe off on to the yard ?

 

[Kristoff28]

Hi Jamie

Many thanks for your reply

I will definatly have enough depth in the joist as its 300mm. Below is a
picture from underneath as we had a major leak, hence the new bathroom

The distance from the new toilet centre point to the outside wall is 1.9m
so a drop of 40mm will be fine i hope ??

Will i need a new outside waste joint or can i drop the whole thing down
and use the blocked off bath/sink outlet above the original outlet ???

cheers

Chris

 

[Kristoff28]

Can anyone help with some sound advice ????

 

[Bahco]

What is troubling you

 

[ajstoneservices]

Engineered joists should only be drilled in the center line or the "knock outs" provided used, most have a maximum hole that can be cut in them typically 38-40mm.

I've seen three storey flats in Kings Lynn with flues passing through the joists The agent wasn't aware you couldn't cut a 115mm hole in them.

 

[Richard C]

Download a copy of Part H of the regs.

http://www.planningportal.gov.uk/england/professionals/en/4000000000382.html

& then you can ensure what your doing will comply with the regs. You need a fall of 1:40 which over 2m (to the external stack) is 50mm.

Just a thought but you seem to be making things difficult for yourself by moving the toilet as far away from the stack as possible, is there any reason why you can’t reconfigure the layout of the room with the w/c over to the left so it’s adjacent to the stack; a short run is also less likely to block! That external boss looks to be solvent weld so you’re going to have to hack the stack at a suitable level; you could use a straight coupler & move the whole lot down & extend the vent back up to the original height but, personally, I would use new fittings as appropriate; the vent pipe above could easily be re-used.

 

[jameshayes]

change your basin for one that is wall mounted with brackets so a pedestal is not required.
check if wall mountable brackets are available for your existing basin.
for example this one. www.worldofbaths.co.uk/wobitem/490
ps if this was my house i woud if stuck with this basin and pedestal,this is what i would do,ok some will say its a bodge but.
box in your soil pipe with 22mm plywood so its very strong,measure distance from bottom of basin to boxed in section,cut with care using an angle grinder.glue base of pedestal to plywood then tile around base of pedestal to prevent movement,yes i know its a bodge but when its all done who will know.
thanks for good clear photos

 

[kirkgas]

it seems a lot of work just to swap the wc and whb, but if it is what you want it can be done, if you plan to run the soil stack under the floor you could fit 110 x 38mm (bath) and 110 x 32mm (whb) boss branch's (what the bath waste is currently connected to outside) into the 110 under the floor in line with the outlets this would keep everything neat and would save a connection/hole in wall outside

 

[blondini]

it seems a lot of work just to swap the wc and whb, but if it is what you want it can be done, if you plan to run the soil stack under the floor you could fit 110 x 38mm (bath) and 110 x 32mm (whb) boss branch's (what the bath waste is currently connected to outside) into the 110 under the floor in line with the outlets this would keep everything neat and would save a connection/hole in wall outside

That's what I would do, just drop the bath and basin wastes straight into the top of the wc branch.

The fall on the branch only needs to be 18mm per metre, in fact it can be as low as 9mm on a long run.

 

[Kristoff28]

Many thanks for all your replys

Kirkgas / Blondini.
Big thanks for your replys, thats the exact answer i was looking for and
the only real solution to get the job done.
I done a small diagram below, is this what you mean or do i drop both
the bath/whb into one outlet on the branch or do one each side of the
branch.
Can these type of branch's be bought, to suit 38mm and 32mm together??

In reply to Richard C,
Yeah its a lot of work but i have purchased a p-shape bath which sits
against the outer wall where the soil pipe goes through and if i had the
toilet and sink the other way round you catch your right knee on the
curved section of the bath when you sit on the toilet.
I tried pinching a few inches moving the sink a bit more but i still kept catching my knee.

I also have to sink the soil pipe underfloor anyway as the whole toilet
including base, sits tight against the wall so there is no gap for the pipe
to get past and there is no way im coring a hole in my new toilet LOL.

Also all the joists are running parallel to the soil pipe you see in the pics
above, so there will be NO cutting of the joists to be done. Thank god

cheeRS

Kris

 

[Goldspoon]

Why not put a false stud wall up? All pipes will then be behind stud wall.

 

[Kristoff28]

Why not put a false stud wall up? All pipes will then be behind stud wall.

Wish i could pal and would save a lot of hassle but my bathroom is small
enough as it is so need all the space i can get plus it will still look like
ive boxed all the pipes in and i hate boxing in. Looks like a bodge it and
scarper job.

Sinking the pipes are my only option or move house LOL

 

[blondini]

It's far better if the wastes connect into the top section of the soil branch rather than the sides. I would take the basin waste straight down behind the pedestal and directly into the soil pipe with a single solvent weld boss like Multiquick Easy Boss. Do the same with the bath waste in a convenient location.

Facilitating easy installation, Easy Boss requires no straps avoiding the need for all-round access to the soil pipe. It can simply be fitted into a 57mm hole and is ready to receive a 1¼ or 1½ inch push fit pipe. For 40mm solvent weld requirements the seal is simply removed and the pipe glued in place, and for 32mm versions an adaptor is supplied as standard.

http://www.multikwik.com/products.php?keywords=easy boss

 

[Richard C]

You'll almost certainly draw the traps every time you flush the loo unless you allow air to get in there somewhere; you need to look at either the BR's or manufacturers design guides or both.