Basement Bathroom Rough-In in North York

Start by finding the sewer depth

A basement toilet drains by gravity only if the sewer line leaves the house below the bathroom floor. In many North York homes it does, because the main drain runs under the basement slab. In others, the sewer exits higher in the wall and the bathroom needs a sewage ejector pump. A camera and a level answer that question.

• Main drain under the floor: gravity drains are likely possible
• Main drain exits through the wall: plan for an ejector
• Existing rough-in capped in the floor: check its size, slope and venting

The rough-in steps

1. Lay out fixtures and mark cuts on the slab.
2. Cut and remove concrete along drain routes.
3. Install drains with correct slope, traps and cleanouts.
4. Run vents to tie into the existing system or a new vent through the roof.
5. Run water supply lines and install valves.
6. Inspect where a permit applies, then patch the concrete.

Backwater protection

A basement bathroom is the lowest place in the house for sewage to come back. Adding a backwater valve is strongly recommended in flood-prone areas, and fixtures may need to be arranged so they are protected.

Local notes

Many basements here have low ceilings and floor drains near the front. Bathrooms near the stack keep vents short. Read the basement bathroom planning guide and see bathroom renovation plumbing.