I'm thinking of having an en suite built upstairs. It's probably going to need a second soil stack installed which will have to link into the existing sewer. The current one runs from a soil stack in the centre of the house and reappears about 250mm from the side of the porch. There there's a vertical pipe with a bend at the bottom about 1200mm deep. The main soil pipe joins into this horisontally abour 950mm down. This pipe runs off to the inspection chamber approx 1400 deep.
Option A: Through a cavity wall and trench about 4m across a garage. The floor is concrete of unknown thickness and hope to intercept the current sewer at some point. I don't think the current pipe is overly deep.
Option B: Trench down the side of the house and round the corner for about 7m to join in the existing drop pipe. The surface here is just earth with paving slabs on top. Also down the side runs the existing rainwater runoff piping from the rear of the house and the electricity supply. At some point the new sewer pipe would have to cross the rainwater runoff pipe from the front which may be an issue.
Option C: Through a cavity wall and trench about 6m diagonally across the garage and out the door to the existing drop pipe. This would bypass all the existing pipes and cables running down the side.
What are the pros and cons of each? What are the potential gotchas that would rack up the cost?
Option A: Through a cavity wall and trench about 4m across a garage. The floor is concrete of unknown thickness and hope to intercept the current sewer at some point. I don't think the current pipe is overly deep.
Option B: Trench down the side of the house and round the corner for about 7m to join in the existing drop pipe. The surface here is just earth with paving slabs on top. Also down the side runs the existing rainwater runoff piping from the rear of the house and the electricity supply. At some point the new sewer pipe would have to cross the rainwater runoff pipe from the front which may be an issue.
Option C: Through a cavity wall and trench about 6m diagonally across the garage and out the door to the existing drop pipe. This would bypass all the existing pipes and cables running down the side.
What are the pros and cons of each? What are the potential gotchas that would rack up the cost?