Moved drains still fall the right way
Why — act while you have leverage
A relocated drain with too little fall does not fail immediately — it blocks slowly, months later, behind a finished wall or under a new floor.
What to look at
- Fall measured along the full length of the new run
- No flat sections or back-falls where the pipe turns
- The connection into the existing stack checked, not assumed
How to check it yourself
A waste line needs a continuous fall to the stack, and moving a WC or a sink often eats the fall that was there. Check the fall along the whole new run with a level before it is covered, and confirm the connection point can still take it. This is the single most expensive interior mistake to correct.
Where this comes from: NBC 2016 Part 9 (Plumbing Services); IS 1742 — Code of practice for building drainage (indian standard or building code)
More plumbing relocation checks
- Photograph before this is covered
- New pipework pressure-tested before it is covered