What is the best drain type for a curbless shower in a Metro Vancouver home?

A linear drain (also called a channel drain or trench drain) is the best choice for most curbless showers in Metro Vancouver homes because it allows the entire shower floor to slope in one direction, making it easier to achieve the precise drainage slope that a barrier-free entry requires. Centre drains can work in curbless showers but require a four-way slope that is more difficult to execute and harder to waterproof at the transition to the bathroom floor.

A linear drain sits along one wall of the shower — typically the wall opposite the entry or along the back wall — and collects water across its full length through a narrow slot or grate. The shower floor slopes in a single plane from the entry toward the drain wall, at a minimum pitch of 1/4 inch per foot (about 2% grade). This single-direction slope is the key advantage for curbless showers because it creates a smooth, flat transition from the bathroom floor into the shower without a step or lip. The bathroom floor sits at the high point, and the shower floor slopes gradually down to the linear drain.

In Metro Vancouver, quality linear drain systems from manufacturers like Schluter Kerdi-Line, Infinity Drain, and ACO ShowerDrain are the most commonly specified by experienced bathroom contractors. A Schluter Kerdi-Line drain integrates directly with the Kerdi waterproofing membrane system, creating a continuous waterproof connection from the shower floor membrane through the drain body — this is a significant advantage in Vancouver's humid climate where any gap in the waterproofing system invites mould growth. Pricing for a linear drain body and grate runs $300–$800 depending on length (24-inch, 36-inch, and 48-inch are common sizes) and grate style (tile-insert grates that match the shower floor tile are the most popular). Installed cost including the drain body, waterproofing connections, and mortar bed slope work typically runs $1,500–$3,000 for the drain system alone.

A centre point drain (traditional round drain) can work in a curbless shower, but the floor must slope from all four sides toward the centre, creating a subtle pyramid shape. This four-way slope makes the barrier-free transition more challenging because the floor is not flat at the entry — it slopes downward from the bathroom floor level on all sides. Some installers solve this by recessing the entire shower area below the bathroom floor level and using a gentle ramp at the entry, but this adds complexity, cost, and requires more structural modification (especially on concrete slab foundations common in many Metro Vancouver homes). Centre drains cost less — $50–$200 for the drain body — but the increased complexity of the mortar bed work and waterproofing often erases the savings.

Tile-insert (invisible) grates are the most popular finish option for linear drains in Metro Vancouver bathroom renovations. The grate frame accepts a piece of the same tile used on the shower floor, making the drain nearly invisible and creating a clean, modern aesthetic. These grates cost $150–$400 more than standard stainless steel grates but deliver a significantly more polished look.

For curbless showers on wood-framed floors (typical in most Metro Vancouver houses), the floor structure must be modified to create the recessed slope toward the drain. This means lowering the floor joists or sistering modified joists in the shower area to create the necessary drop — typically 1.5 to 2 inches from entry to drain. This structural modification adds $1,000–$2,500 to the project and should be done by an experienced framer who understands the load and span requirements under BC Building Code.

For curbless showers on concrete slab foundations (common in Richmond, parts of Surrey, and many older Vancouver homes), the slab must be cut and recessed in the shower area to create the slope. This involves concrete sawing, removal, and patching — typically $2,000–$4,000 for the slab work.

Waterproofing at the drain connection is the most failure-prone point in any curbless shower. The membrane must bond continuously to the drain flange with no gaps, wrinkles, or lifted edges. In Metro Vancouver's climate, where humidity prevents any trapped moisture from drying, even a small gap at the drain-to-membrane connection will lead to water infiltration, subfloor damage, and mould within a year or two. This is why an integrated system like Schluter Kerdi-Line — where the drain and membrane are designed to work together — is strongly recommended over mixing components from different manufacturers.