Installing a bathtub is one of those jobs where errors cost real money. A slope of just a few millimetres — and water ends up on the floor instead of going into the drain. A trap that is not sealed properly — and after a month, damp shows up at the neighbour below. We fit bathtubs in flats all over Warsaw: acrylic, steel, cast iron — and each one needs the right support and the right connection method. If you are planning a replacement or a completely new installation, here is how we handle it properly and what needs special attention.

Safety note: any job involving water supply and drainage comes with a leak risk. One trap not tightened enough, one joint sealed badly — and water gets under the bathtub, into the floor, and down to your neighbours. If you do not have hands-on experience — call a professional. We deal with plumbing every day and know where people most often go wrong.

How much does bathtub installation cost

The cost depends on the bathtub type, the state of the existing pipework, and how much prep work is needed. An acrylic bath on legs is one thing. A cast-iron tub on the third floor in a building with no lift is another story — it can weigh 120 kg, and carrying it upstairs is priced separately. Taking out the old bathtub is billed as a separate item. Current prices for all bathroom services are listed in the table below. Fixings and consumables are included in the price; the bathtub, trap and mixer tap are provided by the client. Waste removal costs extra.

How the installation works

1. Inspection and measurement: we inspect the installation area, the location of the waste outlet and the water supply points. We measure the recess and make sure the bathtub will pass through the doorways and corridor — especially important in older buildings in Zoliborz and Praga.
2. Preparing the base: the floor has to be level and solid. If the screed is damaged or uneven, we level it out. For a cast-iron bath we sometimes strengthen the subfloor so the structure can handle the weight.
3. Fitting legs or the support frame: an acrylic bath sits on its factory cradle (frame) — without it the base bends. A steel bath is set on adjustable legs. Cast iron often comes with built-in feet that are adjusted to level.
4. Levelling: the bath must sit dead level or with a very slight fall toward the drain. We check with a spirit level along the rim in both directions. Wrong tilt is the main reason water ends up pooling on the floor.
5. Connecting the trap and overflow: we install the waste assembly — drain hole, overflow, trap. All joints sit on gaskets and are tightened carefully — too much force on acrylic and the body can crack. We check that the trap runs into the waste pipe at the right gradient.
6. Connecting the water supply: we fit the mixer (wall-mounted or deck-mounted), connect flexible hoses to the hot and cold supply. We test the pressure and inspect every joint for leaks.
7. Sealing the wall joint: we seal the gap between the bath rim and the wall with sanitary silicone. If the gap is more than 5 mm, we first install a trim strip or sealing tape. Without proper sealing, water gets behind the bath and mould starts to grow.
8. Final check: we fill the bath fully and inspect all connections under load. Then we drain the water and check the flow speed and that the surrounding floor stays dry. Only after that do we sign the job off.

Common mistakes

• Bath not levelled — water collects at one end and the drain works badly.
• Acrylic bath installed without a support frame — the base flexes and cracks after a year or two.
• Plastic waste assembly tightened too much — the body cracks or the gasket gets crushed, which causes drips.
• No waterproofing at the wall joint — water gets behind the bath, under the tiles, and mould appears.
• Wrong trap height — the outlet sits lower than the waste pipe entry, so water drains slowly or does not drain properly at all.
• Steel bath with no sound insulation — filling it can be heard through two rooms, and the sides lose heat fast.
• Acrylic bath base not insulated with expanding foam — the water cools down quickly and condensation builds underneath.
• No service access to the trap — everything gets tiled over, and when the trap blocks, the panel has to be broken open.

What to prepare before the visit

• Buy the bathtub and check what comes in the set: legs or frame, fixings, trap with overflow — these are often sold separately.
• Make sure the bathtub will fit through the doorways and the corridor — measure beforehand.
• Remove furniture and loose items from the bathroom — the installer needs clear access to the walls and pipework.
• Check that the isolation valves on both hot and cold supplies work — they will have to be shut off.
• If the old bath needs to be removed — tell us in advance, as it is a separate job with separate waste disposal.
• Check the condition of the waste outlet: if the pipe is old cast iron, an adapter to plastic may be required.
• Choose the mixer type (wall-mounted or deck-mounted) — this decides what holes and connections are needed.
• If you plan to install a bath panel — buy it in advance so the installer can allow for the dimensions during setup.
• Make sure there is clear access to the building entrance and lift — especially if the bath is heavy (cast iron, engineered stone).

A real case from Warsaw

We were called to a flat in Zoliborz — a 1960s building with an old bathroom and a cast-iron bathtub. The owners wanted to swap it for a new 170 cm acrylic model. The first issue was getting the old cast-iron tub out through a narrow corridor. We managed it with two people by standing it upright. The waste pipe was cast iron with a dried-out socket. We installed a reducer to 50 mm plastic and set the drain with the correct fall. The acrylic bath was placed on its factory frame and levelled. We sprayed expanding foam underneath for insulation — the water stays warm longer. We connected the waste assembly, installed a wall-mounted mixer and sealed the rim to the wall with sanitary silicone. We filled the bath right up — every joint stayed dry, and the drain ran quickly. The owners later added a panel and tiled around it. The whole job took about four hours (compatible with Grohe, Hansgrohe, Geberit and similar).

Frequently asked questions

Book your bathtub installation

A bathtub installed properly means no puddles on the floor, quick drainage and no leaks reaching the neighbours. We work across Warsaw and come with all tools and consumables. Acrylic, steel, cast iron — we have fitted every kind. Get in touch — we will set a convenient time and do the job cleanly and properly.