Low level shower tray - will I regret this?

[chrisjmet]

Hi all,

Would welcome your thoughts on this.

I'm installing a low level shower tray, over a timber floor. Cast iron soil stack only about a metre away. So far so good. The problem is that the existing 1 1/2 copper connection into the stack (previously serving bath) enters the stack at a low level and comes up out of the floor at a steep angle, somewhere between 45° and vertical. I haven't been able to find a way to connect to this without introducing a brief uphill section (compression elbow) just before the drop. I realise that this will result in a large portion of the waste run from the shower being filled with water, permanently. Other than raising the shower off the floor, I can't find a way to avoid this. Customer has paid a lot of money for a super thin tray ao hoping it won't come to this. But I suppose it's preferable to having big issues down the line. Any help appreciated, pictures attached.

I didn't mention that the elbow making the connection into the stack is boxed in tight on both sides, by kitchen boxing below. So I can't swivel it without giving myself problems in their brand new kitchen !

Kind regards,

Chris

 

[PETE 123]

If it dont work or keeps blocking up or goes away slow yes you will regret.

 

[gpbeck]

If that 11/2 copper elbow frees up to turn a touch in the stack it would be possible to cut through it leaving just the nut to unscrew? Then you’d just need to work out a connection to the threaded socket.
Or, the part you’ve connected to seems to sit on a thread on the elbow will that free off?

 

[fowlerboi]

Yeah that's rubbish don't do that.

If it was me I would rotate that first compression elbow so that its running parallel to the joists then use some 45's to straighten it up. I can't tell through the picture how that would work drilling new holes on that trimmed joist but you would have to be careful of that too.

Realistically you need to undo those iron fittings on the stack but be prepared to replace the stack if it goes Tete Tong. Time to call a plumber me thinks

 

[king of pipes]

Tricky one that in all honesty it needs stripping back to the cast stack and it's threaded connection, you cannot have a rise however slight you will experience blockages, slow drainage and water will back up into the tray . Kop

 

[chrisjmet]

Thanks all for your replies. I have settled for a lesser-of-two evils option.

I cut the copper coming from the stack elbow back a bit further, and have glued (desperate times) a solvent weld elbow onto the copper using a large quantity of quick setting glue. The rest I have managed to get level enough using fittings. I will wait for the glue to dry and thoroughly test. If the one potentially weak point works then I'm out of trouble, if not it'll be back to the drawing board.

 

[gpbeck]

Would have been better to pass a plastic pipe (even using a reducer) INSIDE that elbow and sealed that because it wouldn't then leak externally. Don't think you've done this. It will be subject to movement because of expansion/contraction and pipework is not fixed, so may leak over time.

 

[chrisjmet]

Would have been better to pass a plastic pipe (even using a reducer) INSIDE that elbow and sealed that because it wouldn't then leak externally. Don't think you've done this. It will be subject to movement because of expansion/contraction and pipework is not fixed, so may leak over time.

Good thinking. I wonder what I could have used that would fit inside 1 1/2 copper and then adapt back to 1 1/2 solvent weld?

 

[gpbeck]

Short length of 32 in the copper elbow?

then

FloPlast WS50W Solvent Weld Waste Level Invert Reducer - White 40mm x 32mm which has a useful offset.​

Or perhaps

FLOPLAST WF07 FLEXI WASTE STRAIGHT COUPLING GREY 30-38MM​

 

[Basher]

or this (takes the place of the copper pipe)

McAlpine Solvent Weld Adaptor White 38mm x 42mm

An essential plumbing tool, this solvent weld adaptor by McAlpine is useful to convert chrome plated brass compression fittings to plastic solvent weld waste pipe. It comes with the ease of installation and is an effective plumbing solution.

www.cityplumbing.co.uk

But you really want that with an integrated elbow! (Edit - as per Fowlerboi's next post!)

 

[fowlerboi]

https://www.NoLinkingToThis/p/mcalp...JnArC0SlrX_IDTIubv8aAqSFEALw_wcB&gclsrc=aw.ds

I appreciate you're putting it on the wrong way round but that sounds infinitely better than bodge you are doing.

Its the same size as a solvent elbow but with a compression end on it. They are brilliant for doing exposed chrome basin wastes

 

[king of pipes]

I can't believe some of this advice whats been achieved is at best a bodge and will inevitably fail over time ,strip the damed thing out out back to the thread yes its a bit tricky but plumbing is don't use fittings which are not intended for that purpose you can get a 1 1/2" bsp x 42mm or 2"bsp x 50 mmm solvent weld adaptor I cant really see what the problem is the only way you would struggle is if you lack the tools to cut the elbow off and extra large grips or stilsons to remove the bush with a bit of heat it's doable . Kop