How to Add a Basement Bathroom

Basement bathrooms live or die on the height of the existing sewer lateral and the location of the main stack.

Common causes

• Existing lateral above or below the basement slab
• Rough-in already in the slab or not
• Available vent path
• Access to the main stack

Step-by-step

1. 01Confirm slab rough-in — 3" toilet, 2" shower, 1.5" sink
2. 02If no rough-in, cut and trench the slab or install a sewage ejector
3. 03Route vent to an existing stack or through the roof
4. 04Waterproof and slope shower pan before tile

When to call Northbridge

• No rough-in and slab needs cutting
• Sewage ejector required (lateral above slab)
• Waterproofing and shower pan liner
• Full permit and inspection needed