Underfloor plumbing problem

[horseshoes]

Last year we had our ground floor bathroom revamped and had a quadrant shower put in and the bath removed. When the plumber was laying the pipes I actually asked him if there was enough tilt for the water to run away freely from the shower. He assured me that there was. It is evident that is not the case. I have had to use Mr Muscle pipe unblocker (and tried the foaming one too) fairly regularly, but this time it doesnt seem to have worked. There's a really unpleasant smell as you can imagine. Digging the floor up is obviously not an option! Please, please tell me there's something I can do.

[Mosaic]

have you done the usual tricks with a plunger...then there's bleach followed by boiling water from the kettle - 20 mins then more plunger?

[The Builder]

In practice, Horse, the "run" (gradient) on a shower waste is not that critical. Obviously it should have some, but, it's more important that the water gets away easily at the other end.
Good practice dictates that there should be an access point where the pipework meets the soil stack/gulley/drain, or whatever. It's usually a screwed cap that can be taken off to allow you to poke back to the shower trap. That trap should be full of water (permanently) to stop smells getting back into the room.
Where exactly does the waste pipe terminate?

[NazNomad]

As usual with plumbers, I suspect there aren't enough pipe supports on an already too-shallow pipe fall. The weight of water in the pipe is sagging it, probably, causing water to remain in the pipe where it should really drain away.

Maybe ...

[horseshoes]

Mosaic - yes done all that. Naz, it's more or less lying directly on to the ground which is why I questioned the slope or lack of it. The Builder, husband is going to look at that tomorrow. If you imagine the bathroom as being square the pipes comes under the floor from the shower in top right corner and go out somewhere in bottom left corner - I hope that makes sense. It's not a huge room. Thanks to all of you. I'll pop back tomorrow and let you know how we get on.

[AlBags]

Many just connect them up and leave them because there is not enough room to get a fall on the pipe. Or they do not want to start making another exit through masonaery, and connect/seal onto stack. Assuming it (the tray) is using a standard shallow trap assembly, check hair is not blocking the trap (the insert/grid should pull out for cleaning) With it out, check the flow away.

[horseshoes]

AlBags, that bit gets pulled out and cleaned regularly so I know it's not that bit.

[horseshoes]

All sorted...... we just have a pipe that goes right to the drain - no trap - no screw top and the water runs out on to the top of the little drain cover, which had got covered in fluff and hair etc.. I'm certain that pipe should extend to beneath the little grid thing. Oh well at least the smell's gone for the time being. thanks for all your help.