I would like to fit a shower in a corner of an extended bathroom - the waste would have to go across the joists to connect with basin / bath waste - don't see how I can sensibly/ practically do this with a 40mm waste pipe. If I run waste along joists to external wall and then through/out to main soil stack, the pipe run will be about 14metres long with a right angled bend- Is this practical /allowable? Its about 11metres from potential shower to external wall - with 8" joists will I even get sufficient fall ?
Shower Waste run
- Thread starter whodareswins
- Start date
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Sorry to confuse - the bathroom is in a Dormer Style Part of the Roof - the waste would need to go through a roof void to reach the external wall and get access to the soil pipe .
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I will try to explain more clearly.
The bathroom sits within a "Dormer" type section of the roof - the bathroom floor is directly above a kitchen below. The bathroom is approx 11ft wide x 15ftlong. I would like to place a shower /tray /surround on the opposite side of the bathroom to the existing waste run which serves a bidet, wc, washandbasin and bath - this waste run then connects to the main(and only) soil pipe external to the property. -The existing waste run is constructed between and parallel to the 8" floor joists - to connect the proposed shower waste into this waste run would seem impossible ? can't notch deep enough to accomodate 40mm pipe and necessary fall nor can you run a 40mm pipe through joist as holes can only be drilled dead centre of joist - again no fall etc. Alternative is to run shower waste also parallel to joists along length of bathroom through "Dormer" wall Into a roof void (also above Kitchen / utility room below), through roof void (parallel to joists) to external gable end then left turn to run to the soil stack on exterior of building - the total pipe run for the waste would therefore be about 11m from shower point to exit point then c 3m from exit point to soil stack. The main question is : Is it permissable to have a waste run of this length (14m) in 40mm pipe? I have read on another site that the maximum run of 40mm pipe to a soil stack should be 3metres. I am also doubtful I will get sufficient fall over this length. - Any professional or practical input appreciated
The bathroom sits within a "Dormer" type section of the roof - the bathroom floor is directly above a kitchen below. The bathroom is approx 11ft wide x 15ftlong. I would like to place a shower /tray /surround on the opposite side of the bathroom to the existing waste run which serves a bidet, wc, washandbasin and bath - this waste run then connects to the main(and only) soil pipe external to the property. -The existing waste run is constructed between and parallel to the 8" floor joists - to connect the proposed shower waste into this waste run would seem impossible ? can't notch deep enough to accomodate 40mm pipe and necessary fall nor can you run a 40mm pipe through joist as holes can only be drilled dead centre of joist - again no fall etc. Alternative is to run shower waste also parallel to joists along length of bathroom through "Dormer" wall Into a roof void (also above Kitchen / utility room below), through roof void (parallel to joists) to external gable end then left turn to run to the soil stack on exterior of building - the total pipe run for the waste would therefore be about 11m from shower point to exit point then c 3m from exit point to soil stack. The main question is : Is it permissable to have a waste run of this length (14m) in 40mm pipe? I have read on another site that the maximum run of 40mm pipe to a soil stack should be 3metres. I am also doubtful I will get sufficient fall over this length. - Any professional or practical input appreciated
You are correct in saying that 3 metres is the maximum recommended length for 40mm discharge pipe from your shower. In practice you will get away with more than this but from the description you have given it sounds like you are asking the waste pipe to do two 90 deg. bends to get to the soil stack over a distance of 11 mtrs. If rate of fall is sufficient you might still get away with it but I would use swept tees at the bends rather than knuckle elbows.
If you have insufficient fall I would raise the shower tray on a plinth or on legs then you can run the waste pipe out via the shortest route above floor level.
If you have insufficient fall I would raise the shower tray on a plinth or on legs then you can run the waste pipe out via the shortest route above floor level.
Thanks for the advice - the idea of swept tees at bends makes good sense.
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