Wet-room kits from China: installer checks
Ask your installer to approve the exact kit against your room: substrates, membrane and drain connection, junction drawings, installation instructions and a testing plan before tiling. Resolve missing details before paying a deposit. Give the approved component list and drawings to Cambridge China Bridge.
Approve the kit against the actual substrate
Give your installer the room plan, floor build-up, wall materials, shower layout and any underfloor heating. Ask them to identify each substrate, including screed, timber, plasterboard, tile backer board or existing tiles. Request written manufacturer confirmation of suitability for those surfaces, with preparation, primer and moisture conditions. Have the installer approve the waterproofed area and assess floor rigidity, board support, falls and finished threshold height.
Ask the installer to approve the membrane, primer, bonding adhesive, tapes, collars and tile adhesive as a compatible assembly. Request a sample trial where adhesion or surface preparation is uncertain. Use our tiler approval guide for tile selection and layout, and our construction materials guide for the separate product documentation checks.
Approve the membrane-to-drain connection
Obtain a section drawing showing how the exact membrane joins the exact drain. Ask whether the connection uses a bonding flange, clamping ring or dedicated collar, and which sealant or adhesive belongs there. Have the installer check flange material, bonding surface, membrane termination and assembly sequence. A drain that fits the waste pipe still needs an approved waterproof connection.
Trial the actual drain and membrane sample together. Check access beneath the floor, waste outlet position, trap cleaning access and grate adjustment for the proposed tile build-up. Ask the installer to compare drainage capacity with the intended shower output. If the drain comes from another supplier, obtain written compatibility confirmation before ordering; do not accept a generic claim that it suits any membrane.
Approve drawings for junctions and penetrations
Ask for drawings covering wall-to-floor junctions, internal and external corners, board joints, niches, pipe penetrations, thresholds and transitions to adjoining surfaces. Mark the extent of waterproofing on the room plan. Have the installer specify the matching tapes, corner pieces and collars, including how overlaps and terminations are formed.
Agree how movement joints continue through the assembly and how later screen fixings or other penetrations will be sealed. Resolve awkward corners with an installer-approved mock-up rather than a sketch supplied after delivery. Put the accepted details and component list in the product specification, with substitutions subject to written review.
Approve usable installation instructions
Request English instructions for the exact kit, with illustrated details and identifiable component names. For liquid membranes, ask for mixing, coat sequence, coverage and wet or dry film thickness checks. For sheet membranes, ask for bonding, overlaps, seam sealing and air-pocket checks. Both need substrate preparation, application conditions, curing stages, repair methods and compatible tiling materials. Have the installer confirm they can follow the instructions on your site.
Request storage conditions, shelf life, batch identification and safety data sheets for chemical components. HSE explains that a safety data sheet does not replace a risk assessment; ask the installer to assess the actual work. Match supporting test reports to the proposed membrane and assembly using our test report verification guide. Settle unclear translations and missing details before placing the order.
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Agree a hold point before tiling
Before purchase, agree who inspects the installed waterproofing and authorises tiling. Record checks for coverage, seams, corners, collars, drain seals and damage. Ask the manufacturer and installer to agree whether a flood test is suitable, the curing conditions, water depth, duration, acceptance criteria and safe containment. Agree the plug position so the test includes the membrane-to-drain seal. Avoid a generic test duration borrowed from another kit.
Keep photographs before covering, component and batch records, test observations and the installer's release to tile. Agree how defects will be repaired and retested. A drainage flow check and a waterproofing test examine different things, so specify both where appropriate. Cambridge China Bridge's staff in China can use the approved brief to request factory documents and check supplied components; site installation and testing remain with your installer.
Frequently asked questions
Can I mix a Chinese membrane with a UK drain?
Ask for written compatibility confirmation for the exact combination and trial the connection. Check the flange, collar, adhesive and assembly detail before ordering.
Will a wet-room kit work on timber or plasterboard?
Have your installer identify the exact substrate and obtain manufacturer confirmation of suitability, preparation and support requirements. A general claim of suitability for bathrooms is insufficient.
How long should I flood test before tiling?
Use a procedure agreed by the kit manufacturer and installer for your assembly. Confirm curing, depth, duration, containment and acceptance criteria before purchase.
What should my installer sign off before I buy?
The substrates, component list, drain connection, junction drawings, installation instructions and testing plan. Resolve missing details and agree that substitutions need review.