Putting in a ground floor loo. Plumbing advice please.

[mike os]

This is covered by building regulations

Minimum fall for 110mm pipe is 1:40 or 40mm per m run
So about 250mm from the drain to the toilet , and sufficient depth for a gulley for the wet room , you will find it difficult to connect the shower drain to a stack/fitting low enough and comply with connection requirements near a toilet

At that length you will need to vent it,, stub stack and air admittance valve should be acceptable but you need to clear with building control

You will need a manhole where the drains connect

 

[gaz1]

as i would do it



false floor in purple 5" or 6" is prefered but 4" raised floor is ample as long as boss strap fitted to the lowest point, the 2 lowest pipe are shower tray and the wet room trap a boss strap can be fitted below the floor space with an access panel built in the floor
the sink drain runs on its own pipe and is inserted higher up the soil pipe on its own boss strap
antivac traps must be used on all 3

a ventcap can be fitted within the bathroom as long as access can be gained to the vent cap also acts as a rodding point or you can vent through the roof
the toilet can be turned if wanted and sink can be moved much closer to the toilet

 

[barracuda816]

Please excuse my ignorance, but when rodding are they rigid? is there any reason you cant rod through a u bend?

Also could i use a trap boss and take 32, 40 or even 50mm pipe from the soil pipe by the toilet to run to the sink shower and wetroom drains (and vertical vent as below; (all red = either 32, 40 or 50mm)

Will that work properly, and do i run a real risk of the toilet backing up and running through any of the drains? Also can i put an access in the red vertical vent for rodding?

I hadn't even considered rodding until mentioned here.

I have had a look at part H, Thanks for the info on that.

Thanks again, Luke

 

[mike os]

Running under a floor will near enough double the cost, and must be encased in concrete

 

[barracuda816]

Sorry i didnt see the last too posts whilst i was posting.

Thanks, Im trying not to run a 110mm stack up the wall as its a small room, but i could loose the smalller bore in the wall by the shower.

 

[barracuda816]

Running under a floor will near enough double the cost, and must be encased in concrete

Thats fine, as we are digging the concrete up in the living room to go to the outside drain (thats already there with a man hole cover).

 

[gaz1]

rodding rods are flexiable enough to go round pot ones but some have got them stuck in there before now

with a sharp radius bend in plastic no the rod wont go round using along radius bend will do it

running it up the wall in the corner wont affect the room not forgetting toilets can be moved or repositioned better

 

[barracuda816]

Ok im nearly there, promise . One more question if i vent the soil pipe just before the toilet is it still a good idea to vent the small bore waste (i.e at the sink?)

 

[mike os]

Ok im nearly there, promise . One more question if i vent the soil pipe just before the toilet is it still a good idea to vent the small bore waste (i.e at the sink?)

No need, as this and the floor require building regulations infections just contact your local authority and discus with yhem

 

[barracuda816]

^ I will do, just want to know what is the best way of doing it before hand (and sound like i atleast kind of know what im doing).

 

[julianf]

If youve not downloaded the relevant building regs document, do so.

Im not a builder, but installed a couple of woodburners a while back. (woodburner, and rayburn with back boiler, etc, along with all the flues)

Document J is the one for that kind of stuff - its very clear, and tells you exactly what's what.

I felt a bit hard done by having to pay £180 for a chap to come round just to say "yep, that's as it should be"

 

[normspanners]

Minimum fall for 110mm pipe is 1:40 or 40mm per m run

Minimum is 1:18 so 18 mm over 1M min and max 6M length for one toilet with 4" I believe

 

[barracuda816]

Am i right in saying according to the regs a length of approx 7m of 110mm soil pipe doesn't require a vent?

 

[normspanners]

is there any reason you cant rod through a u bend?

I would never get my drain rods round a toilet u bend, wouldnt even try bad enough with a bendy spring wire.
I have been very glad I fitted my roding eye, only used it a couple of times, but well worth the effort because my connection is not into a manhole it's 15M then a slow rad 90 then 13M to manhole, and much easier to push it with nothing on the rods than trying to screw a spiral head into 'it' ( missed the SH out!) and drag it out.

 

[normspanners]

Actually You can get a bottle gully drain in red underground with a removable section to facilitate rodding, that has a trap, but might not look that good in a wet room.

found this, that would look better.

http://www.ebay.co.uk/itm/McALPINE-...ILED-FLOOR-STAINLESS-STEEL-GRID-/221442356536

 

[barracuda816]

Thanks, That second one looks pretty good.

Do you know if i have interpreted that part of the regs right? inf i need a vent as its only 7ish metres?

Thanks for all the help guys.

 

[Kayos]

Getting fall on the pipe is easy, 2 foot level with a bit of 15mm copper under the end you want to fall, level it up and there's your fall

 

[normspanners]

It is swings and roundabouts really, the more water from all of the shower/ wet room/handbasin/ toilet the less the soil pipe is likely to block, but if it does block as gaz said it could be possible to get YOUR toilet waste coming out of the wetroom drain because the toilet level is higher than the wetroom drain, unless that waste pipe has a seperate direct run to the sewer manhole. That is what I have done in my bathroom hand basin and bedet to one outlet pipe, shower and bath to another pipe on the other side of the bathroom each outletting to their own combined drain gully trap outside, then there is no poss of toilet waste coming up in the shower or bath and no chance of asmell from the drains because the system is open to free air outside BUT as said I do still get a little glugging in the shower if a full bath is let out as the bath is down stream of the shower and it does tend to pull a little but only when the shower u bend is ready for a clean so lessoning the depth and weight of water in the shower trap. But your only mass of water will be the hand basin and that is probably not enough to pull enough vacuum to empty the other traps IMO especially if you use a vented u bend on the handbasin

 

[mike os]

Minimum is 1:18 so 18 mm over 1M min and max 6M length for one toilet with 4" I believe

That is for branches on a stack, not a sewer, generally building control will want this or close

 

[mike os]

If you are fitting a floor trap you need to be careful setting out your gulley heights or you can end up with issues....

Imo you will need a vent as you have a long run, toilet and other outlets into the same drain... If the outlets go into a gulley you may not need one, but ultimately it will be down to what the inspector wants to see, personally I would have vented anyway