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Postby darrylh » Sun Jan 31, 2010 10:34 pm

hello all!
This is my first post about poor shower drainage and I would welcome any advice.
After moving into a new house, we found the shower drains away very slowly and the tray overflows on full valve (we have to turn the valve down to midway). We wanted to do a bathroom makeover and I took up the floor boards to see if I could improve the waste pipe incline......and found the pipe had been curved over the joists like a banana!! and ffectively waste water was battling uphill before it reached the soil pipe.

I wonder if a sanishower pump would solve the problem or does anyone know of maybe a smaller solution (I need it to fit beneath the shower within the underfloor void) and as space is restricted I'm looking for something that will fit the existing solvent weld pipe (I have already rejected all the caravan and boat shower solutions as they are 3/4 inch outlets). One of my concerns is that the pump would be quite powerfull and would I get any blow back on the other services connected to the soil pipe (bath, toilet and basin)???? Thank you!
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Postby stoneyboy » Mon Feb 01, 2010 9:09 pm

The more complicated you make the drainage system the more problems you will have.
Would it be possible to use the space under the floor to fit a new waste pipe (with the correct falls) and connect into the soil pipe lower down.
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Postby darrylh » Tue Feb 02, 2010 9:56 pm

Hi, thanks for the input.

The property is a barn conversion and the waste pipe runs ACROSS half a dozen joists, where only a couple of inches have been notched out. The soil pipe lies beyond the floor joists. I have had the boards up and don't want to weaken the joists by notching more out, and the soil pipe is where it is .........not much I can do about its location as it is a listed building. I don't necessarily agree with the logic of some aspects of the conversion but unfortunately the conversion has been done.
In terms of a sanishower, I feel there is enough room in the floor void but wondered if the blast from it would create blow back on the other services.
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Postby Zecis » Sun Feb 14, 2010 5:27 pm

Using a Sanishower or something like that is another thing to get blocked/go wrong, and you have to get the right electrics to it, you would be better to work out a way of getting the water out of the barn another way - can't you go out the exterior wall then take the waste around the outside of the building. The other way would not to use 1.5: waste pipe, use a splitter and do a number of runs using thiner pipe, coming together into one pipe again before the soil pipe.
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Postby htg engineer » Sun Feb 14, 2010 6:48 pm

What distance is there between the bottom of the joists and the ground level ?

If there's a void under the floor joists and the soil pipe is under the floor, Why can't you drop the waste to below the joists (no need to notch anymore) and connect into the soil pipe lower down ? (as stoneyboy said)

Or you could build a plinth/base for the shower tray to sit on, even if you have to run the waste pipe as skirting board level - boxed in.

Is this the only shower ? what happens when the pump packs in ? how quick can you buy/change it ? will it be easily accessible.

Also it may be worth looking into notching joists and find out if you can make them abit deeper, without compromising the strength - if it does drain, even though it's slow, it shouldn't need much more taking out to get the fall. Google notching joists - you'll need the dimensions of the floor joists.

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