Surface preparation: The wall and floor base must be flat and firm, removing loose putty, dust, and oil stains. For uneven surfaces exceeding 3mm, leveling with mortar is necessary first. Wooden or light steel keel frames must be securely fixed, with a recommended spacing of 300-400mm. In damp areas, keels should ideally undergo anti-corrosion and rust-proofing treatment.
Materials and tools: Waterproof backing board, rust-proof self-tapping screws, waterproof caulking tape, polymer tile adhesive, utility knife/hand saw, measuring tape, level, sealant.
Boards can be cut on-site; cutting dust is minimal and requires only simple cleanup.
I. Board Fixing (Walls/Ceilings)
Arrange the boards, leaving a 3-5mm expansion joint between boards. Leave approximately 8mm gaps between boards and the ground, corners, and pipe locations to prevent warping and cracking due to thermal expansion and contraction.
Use galvanized, rust-proof self-tapping screws. The screws should be at least 15mm from the edge of the board, and the horizontal and vertical spacing between screws on the board should not exceed 250mm. The screws should be fully recessed into the board surface, but not pierce the surface waterproof mortar.
At corners, it is recommended to bend the entire board or use L-shaped splicing to avoid cross-shaped seams and reduce the risk of water seepage.
II. Waterproof Sealing of Gaps (The most crucial step, often overlooked during construction): For all board joints and corners, first apply a thin layer of tile adhesive to the gap, then press in waterproof fiberglass mesh tape, ensuring the tape completely covers the joint. Apply another layer of adhesive to completely smooth the tape, ensuring no exposed gaps.
For gaps where boards meet the floor, pipes, doors, and windows, after they are completely dry, apply a mildew-resistant, neutral, waterproof sealant to block moisture penetration.
III. Ground Installation Process
After the ground joists or cement mortar leveling layer has completely dried, lay the waterproof backing board, leaving gaps of 3-5mm;
Apply waterproof mesh with adhesive to all board joints;
For areas frequently submerged in water, such as bathrooms and swimming pools, apply an additional coat of waterproof emulsion to the board joints to enhance seepage prevention.
IV. Tile Laying
After all sealed joints have completely dried and cured (at room temperature, wait at least 24 hours) before tiling;
Use the thin-set tiling method directly, without needing additional waterproof membrane, as the waterproof backing board itself has a waterproof structure;
Use anti-mold grout to fill tile grout to further improve moisture resistance.
V. Post-Installation Precautions
Do not spray water heavily within 24 hours of completion, allowing the adhesive layer to fully cure;
Avoid impacts from sharp, heavy objects to the board surface to prevent damage to the surface mortar;
If minor damage occurs to the board surface, smooth it with the matching repair mortar to restore waterproof performance.
Simple tips to avoid common pitfalls:
**Do not use ordinary nails for fixing, as they are prone to rusting, expansion, and damage to the boards;**
**Do not directly join boards without leaving expansion joints, as this will cause bulging in high-temperature and humid environments;**
**Do not apply sealant to inside and outside corners without applying mesh tape, as this will easily lead to water seepage through the gaps over time;**
**Do not directly apply tiles to the joints of boards that are not completely dry, as this will cause hollow spots and detachment.**
