Walk-in (wet room) shower

What is a walk-in wet-room shower?

A walk-in wet-room shower is a fully waterproofed bathroom space where the entire floor and walls form a single waterproof enclosure (called tanking) with a consistent slope toward a drainage point. Unlike traditional shower cabinets or tubs, a wet room eliminates the need for an enclosure frame or shower curtain. The entire bathroom becomes a unified wet space with level-access entry, making it ideal for families wanting flexible, modern bathrooms and for aging-in-place renovations where barriers must be removed. The shower area flows seamlessly into the rest of the bathroom on a single plane, supported by professional waterproofing and engineered floor gradients.

How does floor gradient ensure proper drainage?

The bathroom floor must slope consistently toward the drain at a minimum fall of 12mm per metre (a 1:80 ratio, with 1:60 preferred for faster drainage). This gradient is not left to chance; it is built into the floor structure itself through either pre-manufactured floor formers (shower bases with moulded slopes) or carefully applied cement screeds. A consistent gradient is critical because any low spots allow water to pool, creating standing water that breeds mold and can eventually seep through the waterproofing membrane. Skilled tradecraft is required to verify the gradient with a level throughout the floor before the waterproofing and tiles are installed. The gradient must be formed into the base structure, not improvised on the finished surface.

What is tanking and why is it the foundation of a wet room?

Tanking is the continuous waterproofing membrane applied across the entire floor and up the walls (typically 100mm or more from floor level) to create an impermeable barrier protecting the porous concrete or timber substrate beneath. Two methods are common: sheet membranes (flexible rubber sheets with sealed, overlapping seams that are walked on and tiled immediately) and liquid membranes (rubberized compounds applied in multiple layers, requiring longer drying times). The membrane must extend up all walls in the shower area and surround all pipe penetrations and drain outlets with sealed details. Without continuous tanking, water will eventually seep behind tiles, rot timber framing, and damage the structural floor beneath. The membrane is the invisible guarantee that water stays on top of the floor, not trapped within it.

Why must floor build-up decisions be made before screed is poured?

The floor build-up in a wet room comprises multiple layers in a specific sequence: the structural substrate (concrete slab or timber joists), plywood reinforcement (if needed), drainage channels or point-drain units, the waterproofing membrane, and finally the cement screed that creates the final gradient. Each layer's thickness and placement affects the final floor level and the slope toward the drain. Once the screed is poured and cured (24-48 hours), repositioning drains or adjusting the substrate becomes extraordinarily difficult and expensive. Therefore, the entire layer stack must be designed, approved, and detailed on drawings before any wet work begins. This is why architects and builders collaborate on floor plans early in design; a last-minute drain relocation can delay the project by weeks.

How do point drains and linear channel drains compare?

The drain strategy is foundational to the wet room's success. A point drain (also called a centre or square drain) is a single opening, typically 50-100mm square, positioned in the centre or a corner of the shower floor. Water slopes from all directions toward this single point. A linear channel drain (or shower channel drain) is a continuous slot running along one wall or the centre line of the room; water slopes in one direction toward the channel. Point drains cost 30-50% less to install and are quick to locate. However, they demand a four-way slope (more complex to build correctly), have a smaller opening that can clog or struggle with high-volume water, and create the risk of pooled water in corners if the gradient is imperfect. Linear drains require a single-directional slope (simpler to achieve and maintain), allow continuous high-volume flow, and are strongly preferred for accessibility and aging-in-place bathrooms because the single slope eliminates dead zones where mobility aids or wheelchairs might trap water. They cost more but save on re-work and frustration.

Why are wet rooms popular for aging in place and accessible design?

Wet rooms eliminate the step-over barrier of traditional showers and bathtubs. A curbless entry with a flush threshold or smooth slope allows anyone with mobility challenges, walkers, canes, or wheelchairs to enter without assistance or adaptive equipment. The single-plane floor reduces trip hazards and the psychological barrier of stepping up and over a ledge. For families caring for ageing relatives at home, wet rooms preserve dignity and independence by removing the need for grab handles (though these can still be installed) or mechanical lifts. The minimum accessible shower size is 36" x 36" (roughly 1.1m x 1.1m), and slip-resistant flooring with a coefficient of friction of 0.60 or higher ensures safe footing even when wet. In Slovakia and Central Europe, where multi-generational housing is common and renovation budgets favour lasting solutions, wet rooms are increasingly specified for family homes because they adapt to changing needs over time without requiring major reconstruction.

How do wet rooms in existing homes differ from new construction?

In new builds, the architect and structural engineer plan the floor build-up together, and drainage is installed in the concrete slab or timber framing before the screed is poured. In retrofit projects, the existing bathroom screed must be removed from the wet-room zone, which creates temporary disruption and reveals the structural substrate. Existing pipe routes may need rerouting, and the plumbing connection for the new drain must be carefully coordinated with the building's main stack. Timber-framed existing homes require additional plywood and waterproofing because timber is not naturally water-resistant; the plywood acts as a rigid base to support the waterproofing layer and prevent deflection that could crack the grout or damage the membrane. Retrofits are more expensive and require more planning, but wet rooms still deliver lasting value because once tanked, the space becomes a low-maintenance, flexible bathroom serving multiple family needs.