Smelly shower in brand new bathroom!

Miss.Twizz

It is essentially a completely new installation. The new shower is the opposite side of the bathroom to the old one and the waste pipework for it is new.

I know the low profile showers seem like a trendy fad, we actually would have had a good ol' fashioned step up if we could but the step of our old shower was becoming dangerous for me. I have mobility problems so we needed a more level, easily accessible shower for me. I did check with easy bathrooms and the flow rate for that waste is supposed to be 33l per minute which is double the maximum possible output of the shower. Our shower output is going to be less than the maximum stated because our input pressure is the lower end of the required input range, so it should be well below half the flow rate that waste is supposed to handle.

Jeepers_Creepers said:

How far has the work proceeded? Is the floor down? Would it be destructive to lift part of it up again?

And how far is the shower from the wall the waste goes out?

Yup, the floor is down and siliconed. It could probably come back up if needed but I really hope that won't be necessary 🙈

The fitter is going to replace the 'torica caucho' part of the waste and put some drain rods down incase there are more bits in there from the build. I have everything crossed that that does the trick 🤞🏻🤞🏻

The shower is against the external wall that the waste goes out of, the shower drain is literally about half a metre inside the external wall. It pops straight out then diagonally into the soil stack. I was actually wrong thinking it drops into the horizontal waste pipe, it actually comes out below that and joins the soil stack separately....

The shower waste pipe appears to be as low as it can go before coming outside without ending up below the downstairs ceiling and then it runs parallel to the toilet waste. Looking at this I'm not surprised it smells, the toilet waste has to run right past it 😷 This isn't avoidable though is it? Especially if the shower waste needs a good "drop" then it's going to have to connect below it like that...

(Yes, they're coming back to paint the patches in  the render). 

Jeepers_Creepers

That looks all good, Twizz.

If that exiting shower pipe is as low as it can be, and just above the ceiling below, and it's only a half-metre from that wall, almost certainly it's going to have a good fall on it. So, chances are it's debris (which would be careless and silly, but easily sorted).

Yes, the 33lpm capability of the shower waste is moooore than good enough, but this wouldn't have been the issue anyway. It still relies on the waste pipe having a steady fall, and - if it does - it should work fine.

The smell isn't coming from the, er, contents flying down that 4" soil pipe, but from normal sewage smells wafting up from the sewer in the ground. There, I'm sure that makes you feel a lot better.

The reason (I suspect) that the smells are coming through is that the plumber removed what is the effective part of the trap, and he did this in order to increase the draining speed. The way the pipes have been joined there looks fine.

Fingers crossed the slow draining/pooling is down to debris in the pipe, so when that's removed the full trap can be reinstated.

princeofpounds

Agree with (some of) the others - this is very likely to be a problem with the trap not sealing because the water is not sitting properly within the trap after the shower has finished. We've even had people on this board thinking these kind of traps weren't meant to have water sitting in them, and drying them out, then wondering where the smell came from.

As to why that would happen - a missing part would certainly explain it. The vacuum effect in the pipes mentioned earlier is a possibility.

I've also seen it happen when debris has stopped proper movement of the 'cup' in the trap (on a system where the cup was designed to lower to open the trap when it filled with water) - but that's not your issue.

Missing part - your trap will probably be very similar to this one below in the way it functions. Look at the cut-away diagram on the right hand side (you may have to zoom in), where it says 'water seal 25mm'. Water falls in the waste hole (your 'torica caucho'), is pushed up the sides of the 'sediment' cup below (your second polipropeleno arrow down), then overflows from that cup into the underbody (the bigger cup that the whole unit is contained in, which should be fairly evident in yours), where it then flows out down the pipe. It's easier to see from a diagram like this how it acts like a u-bend, but in a doughnut shape. 

Lift up your cover and see if you have the sediment cup and if it has water in it at various times, as suggested. There are no parts of your assembly that should be taken out.

https://mcalpineplumbing.com/sites/default/files/uploads/installation-instructions/l-st90cp.pdf


Good video on vacuum effect (and many related ways a trap can lose water!) - https://www.youtube.com/watch?v=Y2o8upCxcqA

Miss.Twizz

Thank you Jeepers and Prince! I'm sorry to have gone quiet, I was waiting for the plumber to replace the caucho thingy and have another look at it. Thanks for all your help and the information! It ment I could quite confidently talk about the issue with some semblance of knowledge 😊 

Good news!! It's sorted!! 🥂 The torica caucho cup is back in place and after 48 hours the smell is no more!! YAY! The plumber ended up taking the pipe apart outside trying to find out what was causing the slow draining... Turns out the inner part of the shower waste pipe had apparently slid into the vertical soil pipe causing a partial blockage. Toilet paper (erm etc..) was getting caught up on it, causing slow moving waste water and probably really not helping with the smell! 

Now that's been sorted out the shower smells lovely and it's draining like a dream! Phew!!

Thanks again for all your help and advice. I'm so relieved! I was worried I was going to have a fight on my hands to get this properly resolved and potentially a lot more disruption so I can't tell you how relieved I am that it seems to have been something simple. 

Jeepers_Creepers

Brilliant!

princeofpounds

That's fantastic - thanks for following up, it's great to hear we've been able to help. Also great that you've identified the real underlying problem - have to say it's not one I've heard of before, but makes sense.

Honestly you will not be the last to face this issue!