Is it possible to add an in-floor drain to a condo bathroom that currently only has a tub drain?

Adding an in-floor drain to a condo bathroom is technically possible but involves significant challenges and costs that make it impractical in most GTA condo situations. The biggest obstacle is that condo bathrooms have shared plumbing stacks with carefully engineered drain connections, and adding a new floor drain requires tying into the existing drainage system below your unit's floor slab.

The technical requirements for a new floor drain are substantial. The drain must connect to your unit's existing waste line or the building's main stack, which typically means breaking through the concrete floor slab to access the plumbing below. In most GTA condos built after 1990, the bathroom floor is a concrete slab with the plumbing rough-in cast in place during construction. Adding a new drain connection requires core drilling through this slab and connecting to the waste line that serves your toilet and tub — a complex job requiring professional assessment of the existing plumbing layout.

Condo corporation approval is mandatory for this type of work and often the biggest hurdle. Most condo boards require engineering drawings, structural assessments, and detailed plans before approving any work that affects the building's plumbing infrastructure or structural elements. The approval process alone can take 6-12 weeks and cost $2,000-$5,000 in engineering fees, architectural drawings, and application costs before any actual work begins. Some condo corporations have blanket policies against floor penetrations or modifications to shared plumbing systems.

The waterproofing implications are critical in a condo setting. Adding a floor drain means creating a sloped floor that directs water to the drain location — this typically requires building up the floor with a lightweight concrete or mortar bed, then applying a complete waterproof membrane system over the entire bathroom floor. Any waterproofing failure in a condo affects the unit below, creating liability issues and potentially expensive damage claims. The waterproofing must extend up the walls to create a "bathtub" effect that contains any water within your unit.

Cost considerations make floor drain additions expensive in condo bathrooms. Expect $8,000-$15,000 for the complete project including engineering approval, core drilling, plumbing connections, floor slope creation, waterproofing, and tile installation. This doesn't include potential costs for repairing the unit below if water damage occurs during construction, or the logistics costs of working in a condo (elevator booking, material delivery restrictions, noise bylaw compliance).

Alternative solutions are often more practical for condo bathrooms. If you're concerned about water containment during shower use, consider a curbless shower with a linear drain integrated into the shower area itself rather than a separate floor drain. Linear drains like Schluter Kerdi-Line or similar systems can be installed during a shower renovation without affecting the main bathroom floor or requiring building approvals. A shower niche with bench seating can also improve water management while staying within the existing plumbing footprint.

When floor drains make sense in condos is primarily during complete gut renovations where you're already breaking through the floor slab for other plumbing modifications, or in luxury buildings where the original construction included rough-in provisions for optional floor drains. Some high-end GTA condos built after 2010 have capped floor drain rough-ins that can be activated during renovation.

Professional assessment is essential before pursuing this project. A licensed plumber familiar with condo plumbing systems needs to evaluate your specific unit's drainage layout, determine connection feasibility, and provide cost estimates. The plumber should also coordinate with your condo management to understand the approval requirements and any building-specific restrictions on plumbing modifications.

For most GTA condo bathroom renovations, focusing on proper shower waterproofing, adequate ventilation, and quality tile installation provides better water management results at a fraction of the cost and complexity of adding a floor drain.