Dead leg in cold water feed

[Wibbs]

I have a first floor flat that I am doing a refit in . The current wc is plumbed using 10mm jg. The bath is being replaced with an electric shower . There were originally 2 drain offs on vertical’s for the bath and one drain off on the 10mm vertical for the wc. All other pipe work is 15mm speedfit. If I were to do away with the 10mm wc connection, I would be left with a dead leg in excess of 2m. I cannot start pulling the original ceiling down . Can I combine the old 10mm and new 15mm cold feeds to both shower and toilet with a single drain off to avoid this dead leg ? Unvented system boiler. All feeds drop down metsec stud walls from inaccessible ceiling void.

cheers
paul

 

[Madrab]

I would think that 10mm will struggle to supply suitable flow. Would never consider using 10mm to feed something like an electric shower, certainly not 2 outlets, if that's what you are saying.

 

[Wibbs]

the 10mm feeds the existing toilet. There are two existing 15mm feeds to the bath. I intend to use the 15mm bath cold feed to provide water for the new shower. I was hoping that a 15/15/10 tee near the toilet, combining the shower cold feed and existing 10mm toilet feed would prevent the dead leg in the existing 10mm.

 

[CBW]

I wouldn’t personally use 10 mm for much on plumbing side of stuff. Are you able to incorporate it into something else? What about changing the fitting where it branches from?

 

[Wibbs]

Perhaps this helps. Top sketch is existing. Bottom shows proposed using the tee by the toilet and position for drain off Also by the toilet. If I keep the toilet on the 10mm supply it would then mean two drain offs. All new pipe work will be in tiled boxing. Apologies for the drawing.

 

[Wibbs]

I would also not use 10mm. It is existing. It is not accessible.

 

[CBW]

Number of drain offs doesn’t really matter too much

 

[Wibbs]

They do to my customer when they’re exposed .