How to Choose a Linear Shower Drain for a Shower Niche

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How to choose a linear shower drain for a shower enclosure – complete guide

A linear shower drain has become almost a standard in modern bathrooms over the last ten years. Despite the fact that we see it on every second visualization image, practice shows something different: customers often decide only based on a photo, buy a drain of the wrong length or with the drain opening on the wrong side – and then the mistake is fixed either by the mason or by themselves. This article is here to help you make the right decision from the very beginning, including technical details that most sellers simply don't mention.

We will go through everything from the basics: what a linear drain actually is, why it is worth it (and when it is not), how to choose the right length, position, drain opening, surface finish, and how to integrate the whole selection into the project of a new build or bathroom renovation. At the end, you will also find an FAQ with answers to the most common questions from practice.

What is a linear shower drain and how does it differ from a point drain

A point drain is a round drain that we have known for decades – it is placed in the center of the floor and the floor slopes from all four sides towards it. A linear drain (sometimes also called a line drain or drain channel) is, on the other hand, a long, narrow element – usually 500 to 1200 mm – which is placed along one wall or at the transition between the bathroom and the shower. The floor then slopes in only one direction, which significantly simplifies tiling work: there is no need to cut into corners, tiles can go in one direction along the entire surface and the slope is visually unobtrusive.

If you are interested in a detailed comparison of both types of drains including hydraulics and installation cost, read the article Linear drain vs. point drain – which drain is better in our Knowledge Center. Here we will focus directly on the selection of a linear drain.

From a design perspective, a linear drain is a cleaner solution. The cover grid is part of the bathroom design line and can be made in the same surface as other elements – black, gray, gold, or even with the option to embed tile identical to the floor into it, making the drain almost invisible.

What is the right length of a linear drain for your shower enclosure

This is question number one that customers call with. And the answer is not as simple as "buy the longest one that fits" – it depends on several factors at once.

The basic rule says that the length of the drain should be the same or very close to the length of the wall where you install it. If you have a shower enclosure of 900 mm width and you place the drain along the full width of the wall, you take a 900 mm drain. If, however, the enclosure is 120 × 80 cm and you want the drain along the shorter wall, you need an 800 mm drain.

In practice, you will most often encounter these situations:

Masonry shower enclosure with dimensions 80 × 80 cm: 700–800 mm drain along one wall, slope towards that wall.
Shower enclosure 90 × 90 cm or 100 × 100 cm: 800–900 mm drain, or 1000 mm.
Walk-in without a bathtub, width 120 cm: 1000–1200 mm drain, ideally along the full width of the entrance.
Longer shower enclosure along the wall 160–180 cm: 1200–1500 mm drain.
Smaller shower enclosure or limited space: 500–600 mm drain, placed in the corner or along one wall; suitable also for renovations, where the whole floor cannot be removed.

If you plan a smaller installation or a limited shower enclosure, look at the Linear shower drain SLEEK 500 mm in black or the same model in the variant gun grey – both are suitable precisely for more compact enclosures, where a longer drain simply has no place.

A more detailed calculation method including tables with recommended lengths for different enclosure sizes can be found in the article What length of a shower drain is suitable for my shower enclosure.

Where to place a linear drain – along the wall, or in the center?

The majority of installations place the drain along one wall – typically the wall opposite the entrance, or at the entrance in a corner (which is suitable for walk-in solutions). However, there are also central installations in the middle of the floor, which are compositional and aesthetic, but more hydraulically demanding – the slope must go from both sides to the drain, which requires precise and symmetrical masonry work.

For regular home use, the most practical installation is along the wall. The drain outlet (110 mm) is easier to connect to a vertical waste pipe when the drain is along a wall or in a corner, where the plumbing usually runs. A central drain requires significant rerouting of the waste pipe and greater construction intervention – it is not always possible without breaking the ceiling soffit or the floor in the lower level.

A special situation is corner installation: the drain is placed in the corner of the shower at 45°, which is aesthetically interesting, but requires specific shaped tiles and careful processing of the corner joint. This solution is suitable only for an experienced tiler.

Which side should the drain outlet face

Every linear drain has a drain outlet – usually DN50 or DN75 – at one end or in the middle of the drain body. Before ordering, you must verify the location of your existing waste pipes, or where the mason can build new piping.

For most models in the SLEEK series, the outlet is at one of the ends. This means that a 700 mm drain with the outlet on the left is functionally different from the same drain with the outlet on the right – if you mix them up, the waste outlet will point away from the existing waste and the pipe will need to be extended or rerouted. Always verify the position of the existing vertical waste (sewer column) before ordering, and choose the orientation of the drain accordingly.

Practical tip: take photos of the floor before the concrete screed and mark on the plan the side where the waste is located. This number – the distance from the wall and the edge where the outlet is located – dictates the model selection. Many mistakes occur precisely here: the customer chooses the drain based on color, and only the mason on site realizes that the outlet is on the wrong side.

Hydraulic capacity: how much water must the drain discharge

A standard shower head produces 8–15 liters of water per minute. A rain shower head or a massage system can produce 20–30 l/min. Linear drains are dimensioned to handle this load without problems – with DN50 outlets, the capacity is usually 20–30 l/min, and with DN75 even more.

Drainage problems do not occur during normal showering, but with a clogged trap or with an installation with insufficient slope of the waste pipe. The slope of the pipe behind the outlet must be at least 2 %, ideally 3 % (3 cm drop per meter of length). If the mason does not meet this condition, the drain drains water slowly and after a long shower, water will start to accumulate on the tiles.

More about the correct preparation of the base, the required slope of the floor and masonry techniques can be found in the article Floor slope with a linear drain – how to properly build and tile.

Surface finish: black, gun grey and other options

The cover grid and visible parts of the drain frame are what the customer sees every day. Therefore, the surface finish is important not only aesthetically, but also in terms of durability and maintenance.

The SLEEK series offers two basic color variants: matte black and gun grey (dark steel-gray, with a slight metallic tint). Both surfaces are made using PVD technology (physical vapor deposition), which ensures significantly higher durability than standard powder coatings or galvanic surfaces.

Matte black is the most popular choice for modern minimalist bathrooms, where black also appears in fixtures, mirror frames and accessories. The matte surface has the advantage of being less visible to water stains and fingerprints. The disadvantage is that in insufficient ventilation, mineral deposits from hard water may be more visible on matte surfaces.

Gun grey (sometimes described as anthracite or dark slate grey) is a more versatile choice – it matches stainless steel elements, grey concrete, dark tiles and wooden drywall ceiling moldings. It appears less contrasting than black.

If you are considering the long-term durability of both surfaces and want to know which one lasts longer in harsh conditions (salt mist, acidic cleaning agents, mechanical wear), read the article Surface finish of a shower drain: black vs. gun grey – which lasts longer.

For the black surface, for example, there is the Linear shower drain SLEEK 600 mm in black or SLEEK 700 mm in black, for the gun grey variant SLEEK 600 mm in gun grey.

Material of the channel body: stainless steel as a basis

The channel body – the part embedded in the floor and holding the trap – should be made of stainless steel of class AISI 304 or higher. Some cheap alternatives use galvanized steel or plastic, which under permanent moisture and contact with cleaning agents causes rapid degradation. SLEEK channels are made of stainless steel, ensuring durability without corrosion under normal usage conditions.

The trap is also a key component. Most linear channels use a water-sealed trap (water seal), which prevents the entry of sewer odors from the waste pipe into the room. Some models also have a mechanical flap, which continues to seal against odor entry in case of neglect and evaporation of the water seal (e.g., after a long vacation). Before purchase, check what type of trap is in the channel: the minimum height of the water seal should be 50 mm.

Embedment depth and requirements for the building subfloor

This is a technical detail that customers often forget when choosing, and then the entire installation is ruined because of it. Each linear channel has a certain minimum depth required from the top edge of the cover grid to the top edge of the concrete slab (or expanded clay underlayment). For most standard models, this is 90–115 mm including the body, trap, and tile height.

In practice, this means: if you are doing a renovation and have only 70 mm available from the top edge of the existing screed, a standard channel will not fit there. You either need a thinner special model (so-called "slim") or you have to grind the entire floor and start from scratch. In new construction, this is planned – the architect or construction engineer should consider this when designing the floor construction.

Another factor is the strength of the subfloor. The channel must be embedded in a solid concrete bed. If the subfloor is too soft or not properly compacted, the channel will shift over time or the seal between the frame and the tiles will be damaged, causing water to leak out of the channel.

Grate: types, selection and maintenance

The grate is the most visually striking element of the channel. There are basically three basic concepts:

Grate with straight bars (linear pattern): most common, clean, neutral design. Available in several surface finishes.
Grate with perforated holes (dotted): less common, suitable for certain design styles.
Tile-in surface: a piece of the same tile as on the floor is inserted into the grate – the channel is then almost invisible. Requires precise tile cutting and greater care during installation.

From a cleaning perspective, the classic linear grate is the simplest: it can be lifted, the trap removed, cleaned and returned. Tile-in variants are more aesthetic, but cleaning is more complicated – the grate must be carefully inserted to avoid damaging the tile. A detailed cleaning procedure and recommended products can be found in the article Cleaning and maintenance of the SLEEK linear shower channel.

Integrating the channel into a walk-in shower without a bathtub

Walk-in shower enclosures without a bathtub – with a floor level the same as the rest of the bathroom or with barely noticeable transition – are extremely popular today. A linear channel is almost essential for this type of solution: only it allows the elimination of any step or depression at the entrance. Water drains through a channel placed at the entrance or at the end of the shower area, and if the slope is well done, water never reaches the main floor of the bathroom.

Implementing such a solution, however, requires more precise preparation than a standard shower with a bathtub. The floor in the shower zone must be hermetically sealed – waterproofing (e.g., polyurethane coating or a membrane system) must be applied to the entire area including at least 20 cm on the walls. The junction of the channel grate and the tiles must be sealed with flexible sanitary silicone. Any leaks in this area lead to water penetration into the structure, which is very costly damage in the long run.

Further inspiration and specific project tips can be found in the article Integrating a linear channel into a walk-in shower without a bathtub.

Certification and standards: what to look for when choosing

A linear shower channel comes into direct contact with wastewater and must meet hygiene requirements. In Europe, the relevant standard is EN 1253, which defines hydraulic, mechanical and hygiene requirements for floor drains. The channel should have a certificate or a declaration of conformity with this standard. Furthermore, it is important that the trap meets EN 274 in terms of sealing and prevention of odor entry.

If you are buying a channel for a building where inspection or commissioning is required, inspectors may ask for documents on embedded components. Having a certified product will save you problems.

Common mistakes when selecting and installing a linear channel

From practice, we know that most complaints and problems do not come from a faulty product, but from incorrect preparation or choice. Here are the most common ones:

Wrong channel length: the customer buys a 600 mm channel for a 90 cm corner – the channel does not cover the entire width of the wall, resulting in "blind" corner areas from which water drains slowly.
Neck on the wrong side: installation requires extending the waste pipe, which reduces the slope and worsens drainage.
Insufficient floor slope: the minimum slope prescribed by the standard is 1.5–2 %, in practice 2 % is recommended. Less means that water stagnates on the tiles.
Use of rigid sealant when embedding the channel: the channel body moves slightly with temperature changes – it is necessary to use flexible sealant and flexible joint material around the frame.
Forgetting waterproofing under the channel: waterproofing must be extended under the channel body and outlet, not just around it.
Choosing a cheap channel with a plastic trap: plastics degrade, seals age and after a few years problems with odors or water leakage arise.

If you have encountered any of these issues, the article Common faults of linear shower drains and how to eliminate them will help you. The step-by-step installation process can be found in Step-by-step installation of a linear shower drain.

Price category and what you get for it

Linear drains range in price from about 30 € (cheapest imports) up to 400–600 € and more (design premium models). Where is the line for reasonable quality?

Be cautious with drains under 50 €: the body may be made of alloys or plastic, the trap from a simple degrading material, and the surface finish may wear off after a year. In the 80–150 € range, you will find solid stainless steel drains with good surfaces and standard traps – this includes models from the SLEEK series. Above 200 €, you will mostly find design premium models with exclusive surfaces (gold, brass), tile-in grilles, and special shapes.

For family bathrooms and standard commercial projects, the mid-price category (80–150 €) is optimal – you get a product that will last 15–20 years without problems under normal maintenance.

Most frequently asked questions (FAQ)

Can I install a linear drain in an existing shower area with a bathtub?

Not directly, since the bathtub has its own integrated drain and structure. A linear drain is installed into a masonry or concrete base. If you want to replace the bathtub with a drain, you must remove the bathtub, rebuild the entire area, do waterproofing, slope, tiling, and only then install the drain. It is a renovation, not a simple replacement of one component for another.

What is the difference between DN50 and DN75 necks, and what should I consider when choosing?

DN50 (internal diameter 50 mm) is the standard connection for regular home showers. DN75 is used for higher flow – larger shower systems, wellness facilities, or where the waste pipe is far away and the slope cannot be ideal. For a regular home shower, DN50 is completely sufficient. Before purchase, check the diameter of your existing floor drain.

Can I install a drain in a low-energy house with underfloor heating?

Yes, but you need to consider a few things. Underfloor heating will be interrupted under the drain body – this is not a problem, as the area is small. More importantly, the thermal expansion of the cement screed in underfloor heating is higher, so you must use flexible jointing material and flexible sealant around the drain frame. Otherwise, cracking of the joint and leakage is possible.

How long will a PVD surface on the drain last with regular use?

With proper maintenance (avoiding aggressive acidic cleaners and abrasive sponges), a PVD surface will last 10–20 years without visible degradation. The main enemies are chlorine in cleaning products and mechanical damage from sharp objects. Use a soft cloth and neutral or slightly alkaline cleaning agent for cleaning. More in the article Cleaning and maintenance of the SLEEK linear shower drain.

Is the installation of a linear drain a job for a DIY enthusiast, or should a professional be hired?

Mounting the drain body into fresh concrete can be done by a skilled DIYer. However, there are two critical phases: waterproofing and connection to the sewer system. Waterproofing must be done professionally and without gaps – any defect will show up as a leak into the floor below, which is a very expensive repair. Connecting to the sewer system requires knowledge of regulations and laws (in some regions, it must be done by a licensed plumber). We recommend at least consulting with a professional before starting the work.

Can I install any cover grid on a linear drain, or must I buy an original one?

The drain body and cover grid are dimensioned for each other – the spacing, securing, and depth of seating are specific to each model. If you buy a SLEEK drain, we recommend using original grids. Some manufacturers offer different grid designs for the same drain body – this is fine and allows you to customize the design. Grids from another manufacturer with different dimensions will not fit and may cause instability or leakage around the edge.

Conclusion: How to choose the right linear drain

Selecting a linear shower drain is not rocket science, but it does require answering a few questions before you click "add to cart":

What are the dimensions of your shower area and where exactly do you want to place the drain?
Where is the floor drain located and on which side must the drain outlet be?
How much vertical space do you have – what is the thickness of the floor construction?
Which surface matches the other bathroom elements – black or gun grey?
Will you install underfloor heating, and if so, have you considered it in the materials?

Once you have these answers, selecting a model from the SLEEK linear shower drain range is straightforward. You only need to check availability and possibly consult with installers on specific details of your project.

Further answers to specific questions can be found in the article Frequently asked questions about SLEEK linear shower drains, where we also cover less common situations – extremely small shower areas, historic buildings with limited construction options, or combinations of drains with special types of flooring.

Do you have a question on this topic?

Still unsure or dealing with a specific situation in your home? Write to us – we are happy to help.