Hux

Nick & Peter - thank you for taking the time to input on this. @Nickfromwales, does the above sketch correctly represent your suggestion? Cheers Huxley

Is this what you mean? With the addition of a long radius 90 bend, access point and then another 45 bend. The stack will rise straight in the corner. Tis he Y branch vertically aligned to the pipe running off to the WC. Keeping the stack in the corner really helps with its location as it rises through all floors.

Peter. Bringing the stack 550 back into the room adjacent to the wall would be possible. How does that help with the two changes in direction?

Unfortunately I can't go through the wall at the point shown in the bottom drawing. I need to retain the current entry point to the building as shown in the top drawing. What would be the best way to separate the rest bend from the pipe that serves the WC. Is it possible to branch them in the section external to the wall? With the branch being vertically aligned and not horizontally. So two pipes enter the building, one on top of the other?

To the left of the wall - a light-well at the front of the house. The ground level of the light well is 500mm above the bottom of the soil pipe (as seen). As the waste pipe passes the exterior of the wall, it bends left 90degrees then straight for 1200 then 90degrees right into the inspection chamber where is joins (perpendicular) the the main sewer. If I branch in the light well. Can the pipe to the rest bend drop down into the existing pipe from above it. So two pipes would pass through the wall, one above the other. With the one for the rest bend on top?

Seriously no input from anyone!

Looking for guidance please as I believe I have some challenges in considering the following (please see image) - 1) SVP to rise (vertical arrow) from the basement invert, internally through the ground and first floors into the attic, terminated with an air admittance valve. First floor will branch to family bathroom; toilet, bath, shower and basin. Attic floor will branch to toilet, shower and basin. 2) SVP to branch (horizontal arrow) within the basement floor, 100mm above the finished floor (with appropriate fall) to serve kitchen sink (2m) and small enclosed WC (3.5m). Current Issues: 1.A) Radius of the bend at the base of the main stack - The bend shown in the image is not appropriate as it is less than 200mm radius at the base of what would be the SVP. 2.A) Ignoring the second bend (temporary). The 110 branch would be within 450mm of the invert of the SVP base bend and as such would not be appropriate. 3.A) Where the 110 soil pipe passes through the 9" solid wall, the cavity surrounding the pipe needs to be filled with compressible sealant. What is a compressible sealant? Doing anything with the main stack to make it serve any appliance in the basement is not viable? Options: 1.AA) Provide a slower bend at the base of the SVP. 2.AA) Create a new stub stack, entering the building at the same level of the SVP base. Running from external foul drain to the WC, incorporating a ventilated stub stack. This would serve the basement kitchen sink, Basement WC's basin and WC's toilet, as the toilet is not higher that 1.3m above the drain invert. I cannot conjoin the new stub stack to the main stack? It will need to connect directly to the foul drain? The foul drain serving the an additional stub stack could possibly (low) be subject to surcharging, combined with the sanitary appliance in the basement WC, the addition of an anti-flooding (one-way) valve on the pipe to the stub stack and toilet would be appropriate? Or have I grossly misinterpreted approved document H. Looking for some smart ideas here or means of simplifying the options above so that I do not have to run an additional 110 to the exterior foul drain to serve the Basement WC.