WC into understairs pantry - nightmare

[advisewelcome]

Hi, looking to do two projects:

PROJECT (A): Want to bring garage WC to below the stairs pantry
PROJECT (B): Then maybe turn the garage WC area into a shower room

Pic of the PROJECT (A) basic move:

Pic of the garage WC:

Pic of the pantry area:

Garage WC and Pantry on either side of the same wall with the Garage WC being a step down:

Further pics and details here:
https://photos.app.goo.gl/GtCgH2a9YbByReJy8


First step is PROJECT (A) and its a nightmare tyring to find one person/company to do this at this time.

So working out what I can do myself and the plumbing is the main issue so hence posting here. Can post elsewhere if needed:


I think the steps to do PROJECT (A) is:
1 Get the plumbing in for the new WC by extending waste through the wall
2 Plumb in the feeds for the WC and small sink
3 Fix a stud wall for the cistern and pan to sit against
4 Do the pantry floor
5 Plumb and bolt in the WC
6 Plumb and fix in the sink
7 Fix an ventilation fan
8 Make a door into the hallway
9 Stud wall where the current door is

These steps make sense?

Anything I am missing or anything else worth considering?

Welcome feedback, will have questions. Ta!

 

[Bonni]

Just add to your list - Altering the toilet waste pipe requires building regs.

 

[advisewelcome]

Thanks for the reply.

Do you think it will be a hassle extending that old waste into the pantry? I think its a 110mm pipe extender - the plumber scared the heck out of me by saying that pulling out the old Garage WC from the clay floor collar, could present all kinds of issues - e.g. if the clay waste pipe breaks they would have to dig up the garage floor and replace that part of the pipe?

... is that possible and does it happen often? Or does the old WC generally come out easily and new extension waste piping just plug in?

A shower that will sit over that waste plumbing in the future, so would want to avoid smells and leaks.

Appreciate any thoughts.

 

[denso13]

Do you think it will be a hassle extending that old waste into the pantry?

It depends.

A shower that will sit over that waste plumbing in the future, so would want to avoid smells and leaks.

You'll need to dig down and make a connection to keep everything below floor level. What type of connection depends on what you find.

 

[advisewelcome]

Oh, what am I getting myself into here...

From what I am reading, I guess the WC pan is cemented into the house clay soil pipe and can get thus broken when being removed?

There will a wooded raised floor put in about 2 bricks up to make the garage floor level with the rest of the house...

So, I think the new waste pipe connection to the clay collar will be mostly under the raised wooden floor...

The u bend bit will stick out above it and then go into the pantry WC, I think this is 110mm diameter.

The plan is to put a plinth for a shower tray there and that should cover the u bend bit in the garage room which is about 110mm high. I assume this will also be needed for the shower plumbing to feed into that waste and maybe a sink waste if its fitted in the garage shower room. Not sure how that plumbing will go together.

So if the connection to the house waste pipe will be under the raised wooden floor (if you get what I am saying) - would I still need to dig things up? - or can I just get the waste extension fitted to the collar sticking out of the current floor?

 

[denso13]

Would I still need to dig things up

Yes, you'll need a proper connection onto the clay pipe. Doesn't need to be deep.

 

[Hugh Jaleak]

Biggest risk will be removing the existing Pan without doing too much damage to the soil pipe, if you're lucky, it may break the collar off the clay pipe with the pan, leaving rest intact. Alternatively, you'll have to break the outlet of the pan away, piece by piece, (wear stout gloves, broken porcelain is razor sharp!), and once the pan is off its base, use a Dremel or suitable cutting tool to carefully cut around/through the pipe, under the collar/above the floor to remove the rest.

Then, if the pipe looks ok, (no sign of damage or cracking), use a suitable connector, to take you from the clay to 110mm plastic, go through the wall at a suitable height to meet outlet of new pan. McAlpine offer a version which also has a 40mm boss connection for your proposed shower and basin. https://mcalpineplumbing.com/plastic-chrome-fittings/drain-connectors/drain-connector-with-boss/ (Screwfix stock it , other suppliers are available. )

Digging the floor up is a last resort!

 

[cdbe]

Surely you'd be better knocking through and making a combined WC/shower room? No one wants to take a dump then run round the house to get to the shower.

 

[advisewelcome]

Surely you'd be better knocking through and making a combined WC/shower room? No one wants to take a dump then run round the house to get to the shower.

Hi, looked at that. Because of structural wall in the way - its not worth the hassle messing with that as well as levelling up the floor. Besides the WC/Bathroom would be half in the garage and half under the stairs, and its going to be a bit weird with different ceiling levels and it would be more chillier in the shower section. Also there is a benefit in having WC and Shower rooms seperate with the shower area opening up in the kitchen and the WC opening up in the hallway. Also can manage it as 2 seperate projects - as managing the workmen is major risk in this market. Let me know if in violent disagreement.

 

[advisewelcome]

Biggest risk will be removing the existing Pan without doing too much damage to the soil pipe, if you're lucky, it may break the collar off the clay pipe with the pan, leaving rest intact. Alternatively, you'll have to break the outlet of the pan away, piece by piece, (wear stout gloves, broken porcelain is razor sharp!), and once the pan is off its base, use a Dremel or suitable cutting tool to carefully cut around/through the pipe, under the collar/above the floor to remove the rest.

Then, if the pipe looks ok, (no sign of damage or cracking), use a suitable connector, to take you from the clay to 110mm plastic, go through the wall at a suitable height to meet outlet of new pan. McAlpine offer a version which also has a 40mm boss connection for your proposed shower and basin. https://mcalpineplumbing.com/plastic-chrome-fittings/drain-connectors/drain-connector-with-boss/ (Screwfix stock it , other suppliers are available. )

Digging the floor up is a last resort!

Thanks for this - yes that is the risk I am worried about. Job can turn into nightmare with the Garage WC not usable, no way to connect to a new WC waiting in the pantry - and may be stuck with a workman or plumber that isn't up to the job with no contingency plan. Thus welcome input on the below plan:


PLAN of ACTION
-Use a diamond blade rotary cutting tool to cut around WC (angle grinder maybe)
-Take out the WC
-Put a bag down soil to avoid fragment downs pipe
-Gently hammer inwards the remaining WC fragments if possible without breaking collar
-Possibly fashion tool with rotary diamond blade to remove fragments (read about one somewhere?)
-Put in 4"-to-110mm U-bend connector to go from garage floor through pantry wall (with waste connector for garage sink)

If Clay Soil Pipe Collar breaks:
-Suggested that ARC MS-11 Rapid Seal curing sealant could be useful?
-Mentioned something about a multi-quick collar?
-Can I make the collar flush with the floor or use a deep reach connector if things break?
-Anything else can do if collar breaks?

If Clay Soil Pipe breaks:
-Dig down and replace that section?

...sound like a plan? Missing anything obvs?

 

[denso13]

Put in 4"-to-110mm U-bend connector

What is that?

 

[advisewelcome]

What is that?

I understand soil pipes are 4" (101mm) bore and modern pan connectors are 110mm bore.

Below pic of new raised garage floor (in red) and u-bend connector (in blue):

So something which goes from 4" soil pipe through to pantry wall, offering a 110mm connection to the new pantry WC - and also a waste connection for a future garage sink and shower.

But I assume am not going to get that in one fitting?

Thus do I need a 4" to 110mm connector - then U bend with a waste connection so can t-off to the future garage shower and sink waste.

1) Would it make sense to have this as base connection and then a 110mm u-bend that goes into the pantry WC. The connection to the garage new sink and shower traps would be under the new floor (2 bricks high) and the shower tray directly ontop of the new raised floor.

2) Or would it better to have this as the base connection and then the garage sink and shower waste connection on the top of the u-bend so its above the new raised garage floor - and then plonk a plinth above it and affix the shower tray on top?

Just thinking what is best for maintenance, easy of fitting, access and if there are any additional things needed to prevent soil pipe smells coming out of the new garage sink or shower wastes.

Any of this making sense?

 

[advisewelcome]

... save me from smelling my armpits and wonder why the crickets. Is everyone on holidays or busy doing gigs at this time of year?

 

[Hugh Jaleak]

Is everyone on holidays or busy doing gigs at this time of year?

Yes, actually. Got home and promptly tested positive for Covid, actually feeling more Human again today, thankfully.

If you can get a clean break between the existing pan and drain, then that's the hardest part done I would think. You'll need a selection of fittings to get to where you want to be, but provided drain is ok, (no cracks or other damage), then use the McAlpine DC1-BL-BO (top link in your post), as it'll give you more flexibility on fall with your waste(s). Take off from that with 110mm to meet the new pan outlet position.

 

[advisewelcome]

Thanks for reply.
Yes, the clay collar connection looks like the tricky bit. Once sorted general plan is below...

(A) This is the new raised wooden floor that will be level with the pantry floor on the other side of the wall. This floor will also be level with the kitchen floor and provide easy access to the new garage shower room from the kitchen. On this raised floor will be the new shower tray - probably on a plinth as the new pantry WC 110mm waste pipe (B) will have to go above that new floor and then go through to the pantry new WC (save anyone having to dig up the pantry floor).

(B) This is the soil waste pipe plumbing. Probs consist of a 4" to 110m fitting from the current floor collar - a 90 degree bend - a waste connection for the garage sink and shower - and then an extension to go through to the new pantry WC.

(C) This is the waste connection to the sink and waste. The connection for the garage sink and shower could either be before the bend using this connection or after the bend using this connection first and then this type for the elbow. The 110mm pipe will have to have a plinth above and then shower tray above that. The plughole for the shower could be on the furthest side from the pantry wall which would make it easy to access for any maintenance. I understand that the shower tray plumbing pipe needs a certain min fall. The new pantry WC room may also need a sink and this waste will probs be neatest if coming through the pantry wall and into this garage waste connection.


I guess my questions are:

1) Does this design make sense - or any major issues with it? I am thinking maintenance and access for issues in the future as well?

2) If I dug up the pantry floor I could run the new WC waste pipe extension under the new garage floor (A) and thus avoid having to put the shower on raised plinth by using the before the bend waste connection - but I don't want the hassle of digging up the pantry floor - is this a bad move?

3) Dose it make sense to have the garage new shower plug hole on the furthest side from the pantry wall, rather next to the pantry wall where its close to the waste but impossible to access if there is problem? If so would it make sense to put in a floor trap door access on the new garage floor before the shower tray to get maintenance access to the shower piping?

4) If the (C) waste connection has to be after the bend (for any reason) - are the falls from a shower tray not going to be possible under a shower plinth unless it is a very high plinth and short shower tray (as the shower hole will be other side of the tray for maintenance access).

5) I should thus defo try and have the (C) waste connection before the bend to ensure enough fall gradient for the piping from the shower tray waste?

6) Will the shower tray and sink connections stop any chance of fouls smells from the new pantry WC piping coming up from the sink or shower wastes? Nothing else to be done in the plumbing?

7) I assume it make sense to feed the waste from the pantry WC room sink into the garage waste pipe rather than connecting to the WC pantry pipe.

Welcome any replies.

Am probs overthinking this - but failing to plan is... etc, etc