Threshold-Free Shower: Installation, Benefits and Technical Considerations

A curbless shower is a modern and practical option that provides a seamless transition between the shower and the rest of the bathroom. It is ideal for a clean aesthetic, improved accessibility and easier maintenance . However, its installation requires specific structural adjustments, particularly to ensure proper water drainage and a level floor .

In this article, we will look at the benefits of a curbless shower, how to prepare the floor structure, drainage requirements, and the essential steps for a successful installation .

Why Choose a Threshold-Free Shower?

A curbless shower is becoming increasingly popular in bathroom renovations. Here are some of the main reasons:

• Increased accessibility : No ledge to step over, making it ideal for the elderly or those with reduced mobility.

• Modern and minimalist design : Creates an effect of grandeur and fluidity in the bathroom.

• Ease of maintenance : Fewer joints and obstacles reduce the accumulation of dirt and mold.

• Adaptable to small and large bathrooms : Suitable for both compact spaces and high-end designs.

💡 Tip: Combining a thresholdless shower with large format tiles and a glass wall visually enlarges the space.

Preparing the Floor: Adapting the Structure for a Shower Without a Threshold

One of the major challenges of installing a curbless shower is lowering the shower base so that the bathroom floor and shower floor are level .

1. Cutting and Adjusting the Joists

In a classic construction, the shower is installed above the floor with a built-in tray. For a shower without a threshold, you must:

• Cut out the floor joists to lower the shower area.

• Reduce the height by at least 2 ½ inches below the plywood to allow for installation of the receiver and the discharge slope.

• Reinforce the structure with spacers to ensure the solidity of the floor.

💡 Please note: This type of modification must be done with care so as not to compromise the integrity of the floor.

2. Creating the Slope Towards the Drain

A shower without a threshold requires a gentle slope to avoid water accumulation. Here are the points to respect:

• The slope should be approximately 1 to 2% for effective drainage.

• It is recommended to use a linear drain rather than a central drain, as it provides faster drainage.

• A waterproof coating should be applied over the entire area to prevent water infiltration.

💡 Good to know: Poor drainage can lead to moisture and mold problems. Make sure the drain complies with current standards.

Drainage Requirements: Avoiding Overflows

With an open shower, water can easily spread throughout the bathroom if the drainage system is not suitable.

1. A Drain Designed for Higher Water Flow

A curbless shower receives more water than a conventional shower, so it is essential to choose a drain that can handle a high water flow rate .

• Standards to follow : Check that the drain complies with local plumbing codes.

• Drain Size : A larger drain allows for faster drainage.

• Linear or central drain : A linear drain, placed across the entire width of the shower, is often more efficient than a central drain.

💡 If the water flow is too low, the bathroom may end up flooded after each shower.

Steps to Install a Shower Door Without a Threshold

1️⃣ Preparation of the floor structure : Lowering the ground and installing reinforcements.

2️⃣ Setting up the receiver or slope system : Creating a slope towards the drain.

3️⃣ Installation of the waterproof coating : Waterproofing membrane over the entire surface.

4️⃣ Laying tiles : Choosing a water-resistant covering.

5️⃣ Installation of finishes : Glass wall, accessories and faucets.

💡 Hiring a professional is recommended to ensure a compliant and durable installation.

Recommended Materials for a Thresholdless Shower

• Large format tiles : Fewer joints, uniform appearance.

• Polished concrete : Modern, waterproof and maintenance-free.

• Natural stone : Elegant but requires regular maintenance.

• Waterproof resin : Ideal for a perfectly waterproof shower.

💡 Tip: Combine your threshold-free shower with an underfloor heating system for optimal comfort.

Cost of Installing a Shower Without a Threshold

Element	Estimated price
Lowering the floor	$2,000 – $5,000
Linear drain	$500 – $1,500
Floor coverings and tiling	$2,500 – $6,000
Professional installation	$2,500 – $7,000

💡 Average total price: $7,500 – $18,000 , depending on the complexity of the project.

Conclusion: A Shower Without Threshold for an Elegant and Functional Design

The threshold-free shower is an excellent choice for a modern, accessible and easy-to-maintain bathroom. However, its installation requires good floor preparation, an efficient drainage system and suitable materials .

At BonBain Construction , we support you in the design and installation of your thresholdless shower in Montreal and on the South Shore .

👉 Need an expert? Contact us for a free quote!