Wet Room Conversion Cost: What You'll Pay

Converting a bathroom into a genuine wet room — a level-access, fully tanked, waterproofed shower space with no separate cubicle — typically costs £5,000-£10,000 or more in the UK, noticeably higher than a standard shower installation because of the floor structural work, drainage and waterproofing (tanking) involved.

Why wet rooms cost more

• Floor structural work: a true level-access wet room usually needs the floor built down or a linear drain installed to create fall towards the drain, which on a timber joist floor can mean cutting and reinforcing joists — this is genuinely structural work, not just tiling.
• Tanking (waterproofing membrane): the entire floor and lower walls need a properly applied waterproof membrane system before tiling — this is a specialist skill and a critical step; a poorly tanked wet room will leak, sometimes not obviously until real damage has been done below.
• Drainage: wet rooms typically need either a point drain or a linear (channel) drain, both of which need correct falls calculated and installed precisely — get this wrong and water pools instead of draining.
• Ventilation: because a wet room has no shower enclosure to contain steam, extraction needs to work harder — see our extractor fan regulations guide.

Is it worth it?

Wet rooms are popular for their clean, minimal look and level-access practicality — genuinely useful for anyone with mobility considerations, and often desirable in premium ensuite conversions. But they're a bigger commitment than a standard shower, both in cost and in getting the waterproofing right, so it's worth being honest about whether the aesthetic and accessibility benefits are worth the premium for your situation.

DIY or professional?

This is not a realistic DIY project for most homeowners. Incorrect tanking or drainage falls are one of the most common and expensive-to-fix mistakes in bathroom renovation — water finding its way into a floor or ceiling void below can cause extensive, hidden damage before it's noticed. Use an installer with genuine, demonstrable wet room experience, not just general bathroom fitting experience.

Common mistakes

• Choosing an installer without specific wet room/tanking experience — ask to see previous wet room work specifically, not just general bathroom fitting.
• Underestimating the floor build-up needed for correct falls, which can affect ceiling height below in some properties.
• Skimping on the tanking system to save cost — this is the one area of a wet room where cutting corners has the most serious consequences.

Underfloor heating and wet rooms

Because a wet room floor is already being built up for correct drainage falls, it's a natural point to add electric underfloor heating at the same time — the labour to lift and relay the floor is happening anyway, so the marginal cost of adding heating is lower than retrofitting it separately later. Worth discussing with your installer at the planning stage, even if it adds a little to the initial budget, since undoing a finished wet room floor later to add heating is far more disruptive.

What to check before committing

Ask any prospective installer specifically about their tanking system (a named, established product range is a good sign), how they calculate and check drainage falls, and whether they offer a workmanship guarantee that covers leaks specifically — a genuine guarantee on a wet room installation reflects real confidence in the work, and gives you recourse if something does go wrong down the line.

For a comparison with a standard shower conversion, see our bath-to-shower conversion cost guide, and for the wider bathroom cost picture, see our bathroom renovation cost guide.

Use our bathroom cost calculator for a personalised estimate.