Linear Drain Installation in Warsaw — Floor-Level Shower Drainage

A linear drain means a shower with no tray and no step: water flows straight into the floor through a long slot drain. It looks sleek, works well for people with limited mobility and is easy to clean. But fitting one is nothing like installing a regular shower tray. You need a properly graded screed, reliable waterproofing and a precise connection to the waste pipe. In new builds on Wilanow, flats on Mokotow, houses in Zoliborz — every building has its own floor conditions and screed depth. If you are planning a tray-free shower, call a professional for a site survey. We install linear drains regularly and know where mistakes are most commonly made.

How much does installation cost

The price depends on the drain length, construction type (tile-insert, grated or slot), the existing screed thickness, whether it needs rebuilding and the extent of waterproofing. If the screed is thin you may need to raise the entire floor level or chase a channel for the waste pipe. Installing a drain in a finished bathroom is harder than during a full renovation. Current prices for all bathroom work are in the table below. Fixings and sealant are included; the drain unit and waterproofing materials are supplied by the client.

How the installation works

1. Survey and planning: we determine the drain position, check screed depth, locate the waste outlet and calculate the gradient (at least 1–2 % towards the drain).
2. Base preparation: if the screed is too thin we build it up. We chase a channel from the drain location to the waste stack for the pipe.
3. Laying the waste pipe: we install the pipe at the correct gradient (at least 2 cm per metre) and connect it to the stack.
4. Setting the drain body: we fix it in the screed at the right height, allowing for future tile and adhesive thickness, and connect it to the waste pipe.
5. Waterproofing: we apply liquid membrane to the floor and walls (at least 15–20 cm up), paying special attention to the joint between the drain and the screed. Waterproofing tape is used at corners and junctions.
6. Forming the gradient: we pour a screed that falls towards the drain from every direction and check with a spirit level.
7. Testing: we flood the area with water, check the flow rate and inspect every joint for leaks.

Common mistakes

• Insufficient screed gradient — water pools on the floor instead of flowing to the drain. The only fix is to redo the screed.
• Poor waterproofing — water seeps through the screed and reaches the flat below. The most expensive mistake possible.
• Wrong drain height — after tiling, the grate sits above the floor or is recessed too deep.
• Screed too thin — not enough depth for the pipe and gradient, forcing the entire bathroom floor to be raised.
• Waste pipe with no gradient — water drains slowly, debris collects and the bathroom starts to smell.
• No waterproofing tape at junctions — this is where leaks most commonly begin.
• Drain installed without a trap with a water seal — sewer odour comes straight into the room.

Important: a linear drain involves floor waterproofing and drainage. A fitting error means a leak to the flat below and an expensive repair. If you have no experience with this type of work, we strongly recommend calling a professional.

What to prepare before the visit

• Buy a linear drain of the right length (50, 60, 70, 80 or 100 cm) — confirm the model with the technician beforehand.
• Find out the screed thickness in your bathroom — this determines whether the floor needs raising.
• Locate the waste stack and outlet — take a photo for discussion.
• Buy waterproofing supplies (liquid membrane and tape) — the technician will advise on brand and quantity.
• Clear the bathroom completely — the work is dusty and messy, and the entire floor must be accessible.
• If the bathroom is already tiled, let us know — the floor tiles in the shower zone will need to come up.
• Ensure access to the waste stack and shut-off valves.
• Check whether your downstairs neighbour has a sensitive ceiling — this matters for waterproofing.
• Keep in mind: after fitting the drain, the screed needs 1–3 days to cure before tiles can be laid.

A real case from Warsaw

We were called to a new-build flat on Wilanow. The owners wanted a tray-free shower zone with a 70 cm linear drain along the wall. The floor screed was 8 cm thick and the waste outlet was 1.5 m from the intended drain position. We chased a channel for the pipe and laid it at a 2.5 cm-per-metre gradient. The drain body was set at the correct height, allowing 10 mm for tile and 5 mm for adhesive. Liquid waterproofing was applied in two coats across the entire shower floor and 20 cm up the walls. Waterproofing tape went on every junction. We poured a graded screed and checked the fall from four sides with a spirit level. Two days later we ran a flood test — water drained evenly, not a single puddle, every joint bone dry. The tiler then laid tiles flush with the drain grate. The result: a flat, step-free shower with flawless drainage.

Frequently asked questions

Can a linear drain be installed in an older flat?
Yes, but the floor level often needs raising to provide enough depth for the pipe and gradient. In older buildings the screed can be thin — the technician will assess during the survey.

What length should the drain be?
It depends on the width of the shower zone. A general rule: the drain should be at least 60 % of the zone width, otherwise water cannot drain fast enough under a strong flow.

Is waterproofing necessary if the tiles and grout are waterproof?
Absolutely. Tiles and grout are not waterproofing. Water penetrates through micro-cracks and joints. Without a membrane beneath the tiles, a leak to the flat below is only a matter of time.

Can the drain go in the centre of the floor?
Yes, but then the screed must slope from all four sides, which is harder to execute and more expensive. A wall-mounted drain is simpler and more reliable.

How long does installation take?
Fitting the drain with connection and waterproofing takes 1–2 days. Add 1–3 days for the screed to cure before tiling. From survey to a finished shower — about a week.

Grated drain or tile-insert — which is better?
A tile-insert looks more minimal — only a thin slot is visible. A grated drain is easier to service and clean. Both work identically; the choice is yours.

Book the installation

We install linear drains across Warsaw — in new builds and older properties, during renovations and in finished bathrooms. We visit for a survey, calculate the gradient and height, and fit the drain with full waterproofing. Get in touch — we will discuss your project and arrange a date.