Wet Room

A wet room is any interior space in a building that is designed to withstand regular water exposure and is equipped with waterproofing, floor drains, and moisture-resistant finishes. Common wet rooms include bathrooms, shower rooms, laundry rooms, saunas, and technical utility rooms. Finnish building regulations classify wet rooms separately due to their elevated moisture management requirements.

The construction of a wet room requires careful attention to waterproofing, ventilation, and drainage. The floor must slope toward the floor drain at a minimum gradient (typically 1:100 in the general area and 1:50 near the drain), and the waterproofing membrane must cover the entire floor and extend up the walls to a specified height. All material choices — tiles, adhesives, grout, and sealants — must be approved for wet room use.

Adequate ventilation is essential in wet rooms to prevent excessive humidity from damaging structures and finishes. Exhaust ventilation must be sufficient to remove moisture generated during showers, baths, and laundry. Without proper ventilation, moisture condenses on cool surfaces, promoting mold growth and deteriorating grout and sealants.

Wet room renovations are among the most technically demanding home improvement projects. The work must comply with building codes, and waterproofing must be performed by a certified professional whose work is covered by liability insurance. Cutting corners on wet room construction is the single most common cause of costly moisture damage in Finnish homes.