Fiberglass mesh is an important anti-crack and reinforcement material in construction projects, and its installation quality directly affects the anti-crack effect and durability of the project. Many construction problems, such as wall cracking and mesh exposure, are caused by incorrect installation. In 2026, with the popularization of fiberglass mesh in building insulation and renovation projects, mastering the correct installation method is essential for contractors and DIY enthusiasts. This article provides a detailed step-by-step guide, including precautions for different scenarios.
Step 1: Pre-installation Preparation. First, clean the base surface, remove floating ash, oil stains, and debris, and repair hollowing and holes to ensure the base surface is flat (flatness ≤4mm checked by 2m straightedge) and free of loose substances. Then, prepare materials: select fiberglass mesh of appropriate specifications (≥160g/m² for external wall insulation, 80-120g/m² for internal wall anti-crack), polymer mortar, and tools such as trowels and scissors.
Step 2: Prepare Polymer Mortar. Configure polymer mortar by a special person to ensure mixing quality. The mixing ratio is: KL binder: 425# sulphoaluminate cement: sand (screened with 18-mesh sieve) = 1:1.88:3.25 (weight ratio). Mix cement and sand evenly first, then add the binder and stir until it is porridge-like. The prepared mortar should be used up within 1 hour to avoid deterioration.
Step 3: Cut Fiberglass Mesh. Cut the fiberglass mesh into the required length and width according to the construction needs, leaving a necessary lap length (not less than 70mm for external walls and not less than 50mm for internal walls). Cut it on a clean and flat surface, and roll up the cut mesh to avoid folding or stepping on it.
Step 4: Lay Mesh and Apply Mortar. For external wall insulation: After the insulation board is pasted for 72 hours, apply the first layer of polymer mortar with a thickness of about 2mm, then press the mesh into the mortar, ensuring the mesh is flat and free of wrinkles, with the curved surface facing the wall. After the surface is dry, apply the second layer of mortar with a thickness of 1mm, ensuring the mesh is not exposed.
For internal wall anti-crack: After filling the joint with polymer mortar, paste the mesh on the joint, press it tightly, and then apply a thin layer of mortar to cover the mesh. For gypsum board joints, use self-adhesive mesh, paste it directly on the joint, and then apply putty after drying.
Step 5: Handle Special Parts. For external corners of buildings, add a reinforcement layer, with each side of the mesh extending 150mm. For door and window openings, paste a 200mm×300mm mesh at a 90-degree angle to the corner bisector to enhance the anti-impact performance. For the first floor window sill, lay the reinforced mesh first, then the standard mesh, and the reinforced mesh should be butted.
Step 6: Maintenance and Acceptance. The protective layer cannot be rained on within 4 hours after construction. After the protective layer is set, spray water for maintenance: not less than 48 hours when the average daily temperature is higher than 15℃, and not less than 72 hours when it is lower than 15℃. Check the flatness of the mesh, lap width, and mortar thickness to ensure they meet the standard requirements.
Key Precautions: Do not use ordinary fiberglass mesh in alkaline environments; the mesh must be pressed into the mortar before initial setting to avoid hollowing; avoid rain冲刷 and impact during construction, and take protective measures for easy-to-collide parts.