The installation of extruded polystyrene boards is a critical step in cold storage insulation projects, directly impacting the facility's thermal performance and energy consumption. Strict procedures and specifications must be followed during installation to ensure tight joints, secure fastening, and effective moisture-proof sealing. Below are detailed installation steps and key considerations:
I. Preparatory Work Before Installation
Substrate Preparation
Ensure the substrate of cold storage floors, walls, or roofs is level, dry, and free of debris (such as dust, oil stains, protrusions, etc.). If the substrate is uneven, level it with cement mortar and cure until dry (moisture content ≤8%).
Fill cracks in walls with repair materials to achieve a smooth surface. For concrete floors, ensure strength meets standards (C20 or higher) and apply moisture-proof treatment (e.g., waterproof coating or vapor barrier membrane).
Material Preparation
Extruded Polystyrene Board (XPS): Select appropriate thickness based on cold storage design temperature (-10°C to 0°C: 50–80mm; below -10°C: 80–150mm), meeting flame-retardant requirements (Class B1 or higher).
Adhesive: Use cold storage-specific polyurethane adhesive or polymer mortar to ensure non-brittleness at low temperatures and high bonding strength.
Supporting Materials: Utility knife, tape measure, chalk line, notched trowel, expansion bolts (for fixing), sealant (for joint sealing), mesh fabric (for wall crack prevention), etc.
II. Installation Methods for Different Areas
1. Floor Installation
Step 1: Marking Layout Lines
Mark installation control lines on the floor according to the XPS board dimensions to ensure neat panel arrangement, minimize cutting, and avoid small-sized panels at edges (adjust panels with width <100mm).
Step 2: Apply Adhesive
Apply adhesive evenly across the back of the XPS board (approx. 3–5mm thick), leaving a 50mm border uncoated (to prevent overflow). Alternatively, use the dot-and-frame method (perimeter coating with central dots), ensuring ≥40% adhesive coverage.
Step 3: Laying Panels
Lay the XPS panels flat on the substrate along the control lines. Tap lightly with a rubber mallet to ensure tight contact with the substrate, keeping gaps between panels ≤2mm. Adjacent panels must be laid with staggered joints (similar to brickwork, with a stagger distance ≥1/2 panel length) to avoid continuous seams.
Step 4: Fixing and Joint Treatment
For high-load areas (e.g., forklift traffic), secure panels at all four corners and centrally with expansion bolts (spacing ≤600mm). Bolt heads must be 2–3mm below panel surface and sealed with caulk.
Fill panel joints with specialized sealant or embed matching XPS strips, then sand smooth to eliminate gaps (preventing cold air leakage).
Step 5: Protective Layer Installation
After floor installation, pour a 50–100mm thick fine aggregate concrete protective layer (reinforced with steel mesh) over the XPS boards. Cure until strength requirements are met to prevent panel damage from pressure during subsequent use.
2. Wall Installation
Step 1: Substrate Preparation and Layout Marking
Prepare the wall substrate as for the floor. Mark grid lines to determine panel orientation (horizontal or vertical), reserving expansion joints at top and bottom (10–20mm wide, to be filled with sealant later).
Step 2: Bonding XPS Boards
Begin installation from the bottom of the wall. Apply adhesive to the back of each board, install with staggered joints, and check flatness using a straightedge (tolerance ≤3mm). Remove and reposition any uneven boards to prevent voids.
Step 3: Mechanical Fixing
For walls exceeding 3m in height, secure each panel with 6–8 expansion anchors (≥50mm from panel edge, ≤300mm spacing). Ensure anchors penetrate ≥50mm into the substrate to prevent loosening at low temperatures.
Step 4: Joint Sealing and Crack Prevention
Fill joints with sealant. Apply alkali-resistant mesh fabric across the entire wall surface (lap width ≥100mm), then cover with skim coat mortar (3–5mm thick) to prevent cracking.
3. Roof Installation
Roof installation follows similar procedures to ground applications, but requires attention to drainage slope (≥2%). Panels should be laid in the direction of water flow to prevent pooling.
If the roof has load-bearing requirements, additional support battens must be added or high-strength extruded polystyrene boards (compressive strength ≥200kPa) should be selected. Ensure proper waterproofing is implemented (lay waterproofing membrane over the extruded polystyrene boards).
III. Key Considerations
Moisture-Proof Sealing
Although XPS boards have low water absorption (≤1%), joints must be strictly sealed. All gaps, screw holes, and pipe penetrations must be filled with fire-resistant sealant to prevent moisture ingress that could degrade thermal performance.
At inside and outside corners where walls meet floors or roofs, install corner mesh fabric or additional XPS strips to enhance sealing and crack resistance.
Low-Temperature Adaptability
Adhesives and sealants must be low-temperature-specific products (capable of withstanding temperatures below -30°C) to prevent brittleness and detachment in cold conditions.
After XPS board installation, avoid freezing for 24 hours (ambient temperature ≥5°C) to ensure adhesive curing.
Safety Standards
Operators must wear gloves and masks to prevent inhalation of XPS board dust. Keep away from open flames during cutting (XPS boards are flammable and require fire-retardant treatment).
Wear safety harnesses during elevated work (walls, roofs) to prevent falls.
Following these steps ensures secure and airtight XPS board installation in cold storage facilities, effectively reducing cold loss and lowering operational energy consumption. After installation, conduct thermal performance testing (e.g., using a heat flow meter) to verify compliance with design specifications.
