Replacing Leaking Kitchen Waste & Downpipe Run

[VoidVoyager]

Hi all

I need to replace my leaking waste pipe setup (see photo). The plan is to remove the horizontal clay/cast-iron run and replace it with 110 mm PVC, tying into the existing 110 mm plastic pipe on the left.

I’d really appreciate advice on the best way to connect everything back up, and whether I should be using any bottle gullies and/or an inspection chamber for rodding rather than just copying what’s there.

Existing layout (left to right):

• 110 mm plastic (uPVC) drain pipe
• Old black 2” cast iron waste pipe (approx. 59 mm OD) carrying the kitchen sink waste
• The kitchen waste inside is 40 mm (1½”) ABS solvent-weld, which joins onto the cast iron just before it exits the wall
• Modern 68 mm round uPVC downpipe from the gutters

My proposed plan:

1. Kitchen waste
   • Cut the cast iron kitchen waste pipe near the bottom
   • Connect it to 50 mm PVC using a Fernco Drain Coupling 50–65 mm.
   • Take that 50 mm PVC into the top of the 110 mm drain via a McAlpine Mechanical Soil Pipe Boss Connector 2” on the new 110 mm pipe.
2. Downpipe
   • Fit a FloPlast D96 universal rainwater adaptor (65/68 mm to 110 mm) at the bottom of the downpipe.
   • This will sit in a 110 mm underground 87.5° double-socket bend, which then connects into the new 110 mm drain run.

Does this sound like a sensible way to redo it, or would you recommend a different way of connecting the cast iron kitchen waste pipe, using a trapped/bottle gully for the kitchen waste or downpipe, or adding a section for easier rodding access?

Much appreciated

 

[Hugh Jaleak]

As you suggest, other than I'd connect the Kitchen waste in using a Junction and 110mm-50mm Reducer, rather than a Strap Boss, and I'd probably replace that cast section outside, and run 40mm Pipework though the wall and down, using a 110mm - 40mm reducer.