I. Pre-construction Substrate Preparation
Before construction, clean the original wall and floor substrates, removing loose dust, hollow mortar, and oil stains from the walls. Grind any protruding cement lumps smooth. If the walls have large areas of powdering or looseness, apply a bonding agent first. If the floor has obvious water accumulation or pits, level it with quick-drying mortar to ensure the substrate is solid, dry, and free of looseness. The flatness error of the substrate should be controlled within 3mm. Damp walls should be ventilated and dried in advance. Any seepage points need to be sealed and waterproofed first to prevent continuous backflow from the substrate and affecting the performance of the panels.
II. Panel Cutting and On-site Pre-treatment
Based on the site dimensions and markings, use a utility knife and marble cutter to cut the waterproof backing substrate. Grind the cut edges smooth to prevent sharp corners from scratching the sealing material. Use a hole saw for drains and pipe openings, leaving a hole diameter approximately 5mm larger than the pipe's outer diameter to allow for expansion and contraction. Cut boards should be laid flat indoors and allowed to stand for 24 hours beforehand to acclimatize to the temperature and humidity of the construction site, reducing deformation due to thermal expansion and contraction later. No waterproof coating is needed on the back of the boards, as they have a built-in waterproof structure and require no additional waterproofing.
III. Board Fixing and Installation (Wall/Floor Suitable)
Wall Installation: Use dedicated waterproof self-tapping screws with anti-corrosion washers to fix the boards. Screw spacing should be 30cm horizontally and 35cm vertically. Screws must be driven into the board within 15cm of the edge on all four sides. Screws should be recessed 0.5mm into the board surface, without piercing the internal core layer. Leave a 3-5mm expansion joint at board joints; boards must not be tightly fitted without gaps. For inside and outside corners of the wall, use a single board bent or two boards joined at a 45-degree angle.
Floor Installation: Lay the floor substrate flat, leaving expansion joints between the boards. Apply a thin layer of dry-mixed cement mortar to the bottom of the floor panels to level them, or apply a full coat of waterproof adhesive to the base layer. Do not apply adhesive only in spots, as this can cause the panels to become hollow later. At doorways and shower areas, the floor panels should extend at least 15cm beyond the shower boundary to prevent moisture seepage.
After drilling holes in the floor panels around pipes and drains, do not fill the gaps immediately; leave room for later sealing.
IV. Sealing of Joints, Corners, and Pipes (Core Waterproofing Step)
This step is crucial to preventing leaks and cannot be omitted: Clean all expansion joints and seams of the panels thoroughly, apply the matching waterproof mortar evenly, embed the special fiberglass waterproof sealing tape, and then cover with another layer of mortar, smoothing it out to ensure the sealing tape is completely embedded without any exposed gaps.
For wall corners and the inside corner where the wall meets the floor, use a rounded transition method. First, apply waterproof mortar to create a rounded corner, then apply a widened waterproof sealing tape to enhance the waterproofing performance at stress concentration points.
Fill the gaps around floor drains and water pipes with flexible waterproof sealant, and apply a thicker layer of sealant around the pipe roots to prevent water from seeping into the bottom of the slabs through the gaps.
Allow the entire sealant layer to dry completely naturally, allowing it to stand at room temperature for at least 24 hours before proceeding to the next step.
V. Finishing Installation
After the sealant layer is completely dry, there is no need to apply a large-area waterproof membrane. Tiles and stone can be laid directly: Use flexible waterproof tile adhesive specifically for tiles, applying it using the thin-layer method, with the adhesive layer thickness controlled at 3-6mm. Do not use pure cement mortar, as its rigidity can easily cause tiles to become hollow and fall off due to slight deformation of the slabs.
Fill the tile gaps with anti-mold grout. In shower areas, swimming pools, and other areas with long-term water accumulation, prioritize epoxy-based anti-mold grout materials to further enhance moisture and mold resistance.
VI. Water Retention Test Upon Completion
72 hours after all finishing work is completed, conduct a water retention test to check the waterproofing effect: Fill the shower area with water to a height of 2-3cm, let it stand for 24-48 hours, and check the ceiling, back of the walls, and joints of the panels below. If there is no water seepage or watermarks, the construction is considered合格 (qualified). If leakage occurs, disassemble the corresponding area and redo the sealing process.
Supplementary Construction Precautions
In high-humidity environments such as outdoor areas and basements, stainless steel anti-corrosion screws must be used to fix the panels to prevent long-term moisture, rust, expansion, and damage to the panel surface;
The panels should not be directly exposed to sunlight for extended periods. After completion, they must be covered with a protective layer such as tiles or finishes;
Extremely deep grooves or large-area cuts are prohibited on the panel surface, as this will damage the overall waterproof structure;
Construction is not recommended in environments below 5℃, as the curing speed of sealant and tile adhesive will be significantly slowed, easily leading to sealant failure.
