How to build a wet room

A wet room shower area has design & floor levels similar to the remaining bathroom floors.

Building a wet room can be time consuming & difficult. Your wet room project is unique & our job is to match up your bathroom project with the most suitable wetroom kits. With so much conflicting advice, confusing wet room products, & jargon to consider, you’ll appreciate Riverbed™ helping you make informed decisions about the best wet room kits for you.

Whenever you need advice on the most suitable Wet Room Kits, or Waterproof Tanking, CALL Riverbed™ on 01761 241133

RISK

Wet Room Product choice can be summed up in this single word. RISK

Imagine putting your thumb over the end of a hose pipe with the tap on full. It is the same, speed, pressure & force of water you could have in your wetroom shower. Therefore, the primary objective when fitting a wet room is to reduce the risk of damage from water leaks.

The best way to achieve this is understanding methods of wet room floor construction, the building materials involved, & the waterproofing issues you will face. Additionally, wetroom design & layout can effect successful wetroom installations.

This page will explain some principles of wet room floor construction in more detail.

How to Build a Wet Room –Research, Preparation & Simple Plan

To successfully build a wet room, research, prepare & plan your shower project patiently.

Wet Rooms are about RISK, so reduce this as much as possible. Research & preparation will help in planning your wet room project, so take your time. Your wet room plan must :

• Decide on the end result & how you want to finish your wet room build. Consider Aesthetics, Functionality, & Style among dominant bathroom features & how they are achieved.
• Highlight areas of risk in the wet room, identify solutions, & allow for flexibility within the wet room design & budget.
• Set a realistic Budget for this bathroom project. Use our Calculator to help.
• Consider who will build the wetroom, & why? This affects budget & bathroom product selection.
• Set a Time, Responsibility & Cost for each action during your wet room build.
• Measure & draw up a bathroom plan. Ensure you include all the priority elements you want in your wet room & how to get the end result. Use the plan below.
• Research & refine your wet room product selection by visiting our Shop.
• If you get stuck, call Riverbed™ for FREE WET ROOM ADVICE on 01761 241133

How to Build a Wet Room – PLAN for WET ROOM DESIGN & LAYOUT

Most wet room design issues are common sense, so when you want to plan a wet room, ensure you include:

• Dimensions (preferably in mm) of the wetroom, & each item
• Bathroom Doors & Windows
• Note the wetroom floor structure. Concrete or Wood over Joist.
• Locate floor joists & directions they run in the bathroom
• Decide where & how big you want the shower floor structure within the wetroom. See Below
• Mark down locations for all bathroom Furniture e.g. – WC, Basin, etc
• Layout & Location of the INCOMING & OUT-GOING Pipes.

Most wet room design issues are logical, so consider:

• Doors. Avoid placing the wet room shower area alongside a door, unless you’re sure water will not travel along the wet room floor & underneath it
• The wet room floor is about collecting waste water, & getting it out of the bathroom as quickly as possible. Obstructions slow the water down, so consider wall hung WC’s & Basins.
• Screens, Enclosures, Curtains, & Walls are used in bathroom & wet room designs. They control & confine airborne water, as soggy damp towels, soap, or toilet rolls are unpleasant. Design the wetroom layout with airborne water spray in mind, as it gets everywhere within the bathroom.
• Big Waste Pipes allow more water through, so use 2” (50mm) pipes when building a wet room. Blockages are less likely, reducing the risk of water backing up, & overflowing onto the bathroom floor.

During your Wet Room planning, research options, & make your wet room product selections quickly. With so many variables in building a wet room, establish some basics early. Generally, we’ll assume:

1. the wet room floor finish will be tiles.
   If you want a Vinyl wet room floor finish, click here for more information
2. the wet room floor type will be either
   • wood over floor joists
   • concrete floor of some kind
3. you are a Professional trade fitter, builder, or a competent DIY installer with a basic range of tools, & reasonable levels of knowledge, skill, and experience.

How to Build a Wet Room – PRINCIPLES

This guide to principles of wet room floor construction will help you plan. Essentially all wetroom projects have the same two phases in the build process:

1-Wet Room FLOOR STRUCTURE The Structure of most wet room floors can be broken down into 3 key areas.

i. Gradient This is vital & is where the wet room floor is flat (preferably), but not horizontal. It is used to direct water, by the force of gravity, across the wet room floor to the outlet hole. Without it, water stands or pools, leading to leaks, smells, cold, wet and slippery wet room floor surfaces. The gradient does NOT need to cover the whole wet room floor, but must be within the shower zone & preferably in the ‘drying off’ area too.

ii. Outlet Hole Its location within the wet room floor is important, & the construction must be so it exactly matches the waste & trap (or gully / shower channel). If not a perfectly matched pair, (or the join relies on an additional seal. e.g. Silicone), the wet room floor structure may not be secure. This increases the risk of water leaking through the outlet hole, instead of travelling down the waste & trap. The Outlet Hole must also be at the LOWEST point in the wet room floor.

iii. The Waste & Trap A device to join the outlet hole in the wetroom floor to the drains. With a defined specification to meet building regulations, the wet room waste & trap stops smells & should be a simple & secure method of joining to pipes. Some are more complex to assemble, & thus less suitable for DIY installers. Ask Riverbed™ about the most suitable wet room products for your installer. Wet Room shower channels, & wet room gully’s are specialist forms of Waste & Trap requiring separate fabrication of both wet room floor gradient & outlet hole. Waste & Trap flow rates must exceed incoming shower water volume, otherwise water will back up, flooding the wet room floor

2-Wet Room WATERPROOFING (TANKING) Ideally, you’ll build multiple layers, each one acting as a defence against water leaks through the wet room floor. Combined, the sum of layers offers a greater defence than the individual layers alone. There are many different methods of waterproofing or Tanking a wet room, so with such low costs, why risk leaks by cutting corners?

Call Riverbed™ on 01761 241133 to get FREE ADVICE about the different tanking systems.

i. Wet Room Floor Covering (Primary Defence) Wet room floor & wall coverings are not just decorative, but are also the 1st. Line of Defence against leaking wet rooms. Decide early about having a Tiled or Vinyl wet room floor finish, as this is the most important thing when planning the wet room waterproofing.

• TILES - Tile grout is generally porous so the more holes, or gaps between tiles, the weaker the wet room defence. Large floor tiles have fewer gaps, so offer better wet room defences (& thus lower risks) than smaller tiles. Small mosaic tiles have some anti-slip properties & are easier to fit on curved surfaces, but have many gaps & offer a higher risk.
• VINYL - Alleged health advantages encourage regular use in Commercial, Industrial or Institutional buildings. Perceived as having a lower quality finish, Vinyl offers less flexibility & fewer wet room design options. A specialist installation, the aesthetics are an acquired taste and long term bathroom durability is questioned as it can be punctured, & damaged more easily than tiles.

ii. Waterproof Wet Room Tanking (Secondary Defence) Used below the floor covering to seal the wet room stopping water leaks causing damage. Available separately from wet room shower bases and included with many ‘All-Inclusive’ wet room kits. With so many wet room tanking systems, each offering different benefits, one usually becomes the best solution for a particular wetroom project, ahead of the others. Competing systems offer huge differences in

• Material Quality
• Tooling Required
• Wet Room Tanking Installation Time
• Installer Skill & Patience needed
• Simplicity & Ease of Assembly
• Knowledge & Experience of wet room Fitter
• Wet Room Waterproofing Costs
• Compatibility Issues with other wet room products like Under Tile Heating

Call Riverbed™ on 01761 241133 to get FREE ADVICE about the different wet room tanking systems.

iii. The Floor Structure (Final Defence) Should the first two lines of wet room defence fail, it is sensible having a final line of defence (the original structure or shower base) that is also waterproof. Ideally, not wooden, a well designed, built & waterproof wet room structure helps reduce the overall risk

BEWARE. Some wet room shower bases (offered elsewhere) are a structural solution ONLY, & are NOT made from Waterproof material. Therefore, we cannot recommend any wet room product made from such materials (e.g. plywood) when it forms the primary wet floor area.

IMPORTANT

Leaking Wet Rooms are caused by trying to save time, energy, effort or money. We’ve had examples where experienced plumbers, builders, or other tradesmen have during the wet room build fitted either

i) The Structure ONLY
or
ii) The Waterproof Tanking ONLY

YOU MUST DO BOTH WET ROOM STRUCTURE & WATERPROOF WET ROOM TANKING !

YOU CANNOT JUST CONSIDER THE WET ROOM FLOOR STRUCTURE, OR THE WATERPROOF WET ROOM TANKING ALONE.

When asked for solutions to solve leaks in these wetrooms, without doubt, the best (but the most expensive, time consuming & stressful) solution was to rip everything out and re-build the wet room fro