A wet room is a bathroom where the shower area is open and the whole floor is designed to get wet. That makes it different from a bathroom with a bath or a shower tray. The real waterproofing is underneath, and the sealant on top is there to protect the joints where movement happens. This guide explains where sealant goes in a wet room, why the layer underneath matters more, and how to spot a seal that has failed.
Tanking comes first
A wet room should be tanked. That means a waterproof membrane or system is applied to the floor and walls before tiling, so water that gets through the tiles and grout can’t reach the structure. The floor is laid to a fall so water runs to the drain.
Tiles, grout and sealant are the visible surface. They shed most water, but they are not the main waterproof layer. If the tanking is missing or damaged, no amount of sealant on top will make the room watertight. That is a job for whoever installed the wet room or a specialist, not a sealant fix.
Where sealant goes in a wet room
- Floor-to-wall junctions, where the tiled floor meets the tiled walls, especially in the shower zone
- Internal wall corners in the shower area
- The base and sides of a glass screen, where it meets the floor and wall
- Around pipes and fittings that come through the tiles
- Junctions with other materials, such as a basin, WC or door threshold
- Movement joints in the floor tiling, where the design calls for them
These are the joints where the surfaces move slightly against each other, so a flexible sealant is used instead of grout. Our guide to regrouting or resealing explains the difference.
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Choosing the right sealant
Wet rooms need a sanitary silicone with an anti-fungal additive, suited to permanent wet areas. On the floor, it also needs to cope with foot traffic and cleaning. The joint must be clean and dry, with no soap or grease left on it before sealing. In a room that is used every day, getting it truly dry is the hardest part, so the room may need to be out of use for a while before and after sealing.
Signs a wet room seal has failed
- Black mould in the sealant at the floor-to-wall joint
- Sealant that has split or pulled away, especially at corners
- Staining or damp on the ceiling below, or on walls outside the room
- Damp skirting boards or flooring just outside the door
- Loose or hollow-sounding tiles, which can mean water has got behind them
- Water pooling instead of running to the drain
The first two are usually sealant problems. The others can point to failed grout, tanking or plumbing, and need investigating before anyone reseals. Our guide to leaking showers covers the basic checks.
Resealing a wet room properly
A wet room reseal follows the same rules as any other. All of the old sealant is cut out, the joint is cleaned and any mould treated, the joint is left to dry fully and a single bead of anti-fungal silicone is laid and tooled. The difference is that more joints are involved and drying takes longer.
We reseal wet rooms in homes, offices and care settings. At Manor Royal, an accessible wet room was resealed alongside staff shower rooms and a kitchen. See our bathroom resealing service for how we work.
Quick answers
Can sealant fix a leaking wet room?
Only if the leak is through a failed sealant joint. If the tanking underneath has failed, the floor needs a specialist repair.
How long before the wet room can be used?
Keep water off new sealant for the cure time given, usually around 24 hours.
Do wet rooms need resealing more often?
Joints that are wet every day and walked on can wear faster. Good cleaning and ventilation help them last.
Related services
More advice
- Leaking Shower? How to Tell if It’s the Sealant
- Regrouting or Resealing: Which Do You Need?
- Sealant in Commercial Washrooms
- All advice
This guide is general information about sealant work. It isn’t legal, fire-safety or structural advice; for those, speak to a qualified professional.