Measured in square metres, wet rooms are the most expensive rooms in any house and defects can lead to serious secondary damage. Careful planning and control of both design and construction are therefore essential to minimise the risk of defects, failure, and damage. Project-specific checklists should be drawn up for use in the design, project review, and construction phases. The checklists should be adapted to specific projects, but at minimum should contain the following:
Does the wet room design meet the requirements stipulated in the Building Regulations, building permission, the norm for water supply systems, high-voltage power regulations, and other applicable regulations?
Has the anticipated usage (load class) of the wet room been assessed?
Is the wet room small or exposed to high loads? If so is this incorporated into the design?
Are measures in place to protect moisture-sensitive constructions such as doors and windows?
Are measures in place to secure the routing of installations?
Are the load class, planned constructions, and choice of materials compatible?
Has masonry movement between building parts been considered?
Does the project meet the building owner’s expectations of safety and robustness?
Does the wet room comply with applicable requirements for access in terms of layout, door-step height, and depth of recesses?
Does the wet room comply with acoustic insulation requirements (if applicable)?
Have adequate specifications of all constructions, materials, and work operations been drawn up?
Have adequate specifications of installations, routing of pipes, channels, and cables as well as floor and wall penetrations been prepared?
Have CE-marked/VA-approved fixtures and fittings been specified?
Have drawings of all required details (not merely references) been prepared?
Has a user manual (e.g., for maintenance and repair) been prepared?
Is the quality assurance system adapted to the solution’s sensitivity to defective constructions?
Has a quality assurance system been designed?
Has a start-up meeting been convened to coordinate workers and discuss and resolve any ambiguities?
Is there a plan for ongoing control of the work (i.e., in tandem with the work being done)?
Is an agreement in place for inspections and focus areas, such as difficult work processes?
Has a work plan been prepared to note down work progress and deviations from the plan?
Has a decision been made about how potential deviations in the progress plan should be handled?
Has a decision been made about how to arrange and document potential changes in construction and installations?
Has an agreement been made about who will prepare ‘as-built’ drawings and specifications?
Is the project material clear and meaningful?
Are all details specified and drawn?
Is the time schedule realistic?
Is the building site ready for the work to start?
Have requirements for moisture content, etc., in existing constructions and sheet materials been complied with?
Is there a specific plan for how to check the quality of work?
Do wall constructions comply with specifications?
Are adequate structures in place for fixing the toilet, washbasin, grab rails, and other bathroom fixtures?
Does the floor construction comply with the specifications?
Are joints between floor and walls watertight (e.g., are watertight flashings and a waterproofing membrane continued min. 100 mm up the wall)?
Are finishes around the door installed correctly (either with a 30 mm difference in height between the top of the waste outlet grid and the floor surface by the door, or with a 20 mm difference in height between the floor surface and the top of the doorstep)?
Are there slopes towards the floor gully (e.g., 1 % fall in the shower stall)?
Is the floor free from depressions? Pooling must max. be 250 mm long and/or max. 1 mm deep.
Is the waterproofing system applied according to the manufacturer’s instructions and the MK approval or ETAG, if applicable (e.g., with primer, min. 1.0 mm thick waterproofing membrane in the wet zone, tile adhesive, etc.)?
Are fixtures and fittings CE-marked or VA-approved?
Is the floor gully compatible with the chosen floor covering (e.g., documented by a VA approval)?
Has the gully been installed correctly and positioned with the edge of the gully base min. 150 mm away from the walls?
Has the gully been positioned correctly and spaced 60 mm away from joists (for concrete on timber joists)?
Has the floor gully been correctly and securely fixed to the floor?
If using a channel drain, does it have an MK approval documenting that it can form part of a watertight construction?
Has the waterproofing system or the watertight covering been coupled to the waste floor gully correctly?
Are pipe penetrations in the floor positioned outside the area expected to sustain regular water exposure?
Are pipe penetrations in the floor positioned with the correct spacing from the walls?
Are pipe penetrations installed correctly with a watertight joint against the floor and/or the walls?
Is there access to the waste outlet for cleaning purposes and can the trap be easily removed?
Has the concrete or lightweight concrete cured sufficiently before commencing the tiling? Dates for installation, concreting, and tiling should be updated.
Have resilient joints been made with the correct joint width and with a backstop?
Has everything been carried out as planned? If not, were changes agreed upon?