Precautions for metal solar roofs mainly include the following aspects:
Waterproofing: Waterproofing of metal solar roofs is the core link. The drilling position must avoid the original joints. After drilling, apply weather-resistant sealant immediately and cover with a stainless steel rainproof base. Rubber gaskets are installed at the connection between the photovoltaic panel bracket and the roof, and the bolt tightening force is moderate to prevent excessive extrusion and deformation of the metal plate. Sufficient maintenance space is reserved in the drainage ditch and gutter area, and it is prohibited to install equipment above the drainage path. Load calculation: Load calculation needs to consider comprehensive factors such as the weight of photovoltaic modules, bracket system, snow accumulation, and wind pressure. The wind load coefficient in coastal areas is designed at least according to the local 50-year standard. The snow load in northern areas is calculated according to the maximum snow thickness. The bracket inclination angle needs to be adjusted in combination with the latitude to avoid snow accumulation from crushing the roof. Bracket material selection: The bracket material is preferably aluminum alloy or hot-dip galvanized steel, which has strong corrosion resistance. The bracket spacing is customized according to the size of the photovoltaic panel, and the horizontal and longitudinal errors are controlled within 3 mm. Leave a ventilation gap of more than 20 cm between double-row components to prevent heat accumulation from affecting power generation efficiency.
Electrical construction: Separate the DC and AC lines, and install a leakage protection device on the AC side. Use waterproof threading pipes when cables pass through metal roofs, and the pipe mouths should be cut-resistant. Ensure good ventilation at the inverter installation location to avoid direct sunlight. The grounding resistance of all electrical equipment is less than 4 ohms, and the lightning protection grounding system must be reliably connected to the original lightning protection belt of the building.
Construction safety: Take good safety protection during construction, workers wear five-point safety belts, and set up temporary guardrails on the edge of the roof. Avoid construction at noon in hot weather, and suspend operations when the surface temperature of the metal roof exceeds 60℃. When heavy equipment is hoisted, install a temporary support frame under the stress point of the roof.
Regular maintenance: Clean the photovoltaic panels, check the bracket fasteners, and test the insulation resistance every quarter. After a storm, focus on checking whether the waterproof seal has failed, and polish and repaint the rust points in time. Check the line connection and inverter working condition when the power generation drops abnormally.
Policy requirements: Pay attention to local policy requirements. Some cities have height restrictions on rooftop photovoltaics, and industrial and commercial buildings require construction permits.
