Roof waterproof
The general principle of roof waterproofing treatment is that it should be guided and not blocked, that is, to ensure that the nodes can smoothly drain water during stormwater accumulation and ensure that the roof is not leaking. Therefore, when designing, the support base should not be arranged perpendicular to the drainage direction first, so as not to hinder the drainage of rainwater on the roof. In addition, when the photovoltaic system is installed on the existing roof by directly placing the support base, the base does not have a relationship with the structural layer of the original roof. Therefore, to ensure the safety of the structure, the base must be placed smoothly and neatly. , And need to take measures to fix, to avoid overturning, slipping and other phenomena. Since there is no relationship between the base and the structural layer, it is difficult to install an additional waterproof layer. The original waterproof layer should be kept as far as possible to prevent leakage.
For the case where it is necessary to punch holes to destroy the original roof, we must adapt to local conditions and deal with it differently according to different situations.
1. Waterproof concrete flat roof or concrete slope roof of the villa
For new construction of concrete flat roof or villa concrete sloped roof (overlay tile), usually, bolts should be embedded in the design, and roof waterproofing should be done in accordance with conventional practices.
For existing buildings with flat concrete roofs or concrete slope roofs (overlay tiles) for villas, the roof structure should be confirmed first. When the photovoltaic module base is connected to the structural layer, the periphery of the metal embedded part on the top of the base is a weak link for waterproofing. If it is not handled properly, rainwater will easily infiltrate from around the bolts of the embedded part to the structural layer, which will cause corrosion of the structural steel's stress reinforcement, Forming hidden dangers. Therefore, when setting the photovoltaic module base, the waterproof layer should be laid on the base and the upper part of the metal embedded parts, and sealed around the anchor bolts. The waterproof layer should be filled with a waterproof sealant to prevent the water from seeping in the rain. Outside the path, an additional waterproof layer should be added to the lower part of the base. Even if the top of the base leaks, rainwater will not reach the structural layer.
2. Waterproofing of metal roof
For the metal roof, the steel structure of the photovoltaic system needs to penetrate the original waterproof layer and the profiled steel plate and be fixed to the main steel structure of the building; and then refer to the metal roof waterproof practice for steam insulation, heat insulation, and waterproof treatment. The focus of the construction is to remove rust, seal, and apply waterproof coatings to the base layer and the periphery.
For local leaks on metal roofs, high-quality neutral weather-resistant sealants should be used for plugging. For locally corroded color steel plates, they need to be replaced before installing photovoltaic modules.
1) For the case where the cross-section of the color steel plate is trapezoidal: The photovoltaic bracket is usually connected to the color steel plate from the side of the top surface by self-tapping bolts. Self-tapping bolts must be equipped with matching weatherproof sealing and waterproof gaskets. After the self-tapping bolts are fixed, the screws must be coated with a high-quality neutral weather-resistant sealant.
2) For the case where there is a cable bushing through the roof panel: all methods are available on the existing national standard atlas. Design and construction can be selected according to the actual situation of the actual project.
3) For the case where the cable passes through the roof panel: Detail cover sheet can be used for waterproofing. Detail cover sheet is a roof waterproof structure, which is often used in colored profiled steel sheet roof. It has good physical properties and chemical resistance and can overcome the problems of water leakage of rigid waterproof materials.
3.Waterproof treatment of roof punch
For existing buildings with concrete flat roofs or concrete slope roofs of villas, if the brackets are fixed with chemical anchor bolts, the thickness of the protective layer or surface layer should be confirmed first. For a prefabricated floor roof with a large unit load, a concrete layer of a certain thickness can be cast on the roof, and the bracket can be fixed by chemical anchor bolts after curing. For sloped roofs covered with tiles, the drilling depth should be confirmed. After the chemical anchor bolts are fixed, the position where the bolts pass through the tiles should be well treated with a waterproof sealant. Due to the large load-bearing capacity, chemical anchor bolts are resistant to fatigue and aging, and some models can withstand dynamic and impact loads; they have no expansion force on the substrate and no compressive stress, so they will not adversely affect roof waterproofing.
Conclusion
During the construction of the distributed photovoltaic power generation system, there may be a risk of rain leakage from the roof, which should be paid attention to. From the project site survey stage to the deepening design stage, it is necessary to make a full estimation and justification of the possible leakage risks of the roof in the future, and to conduct detailed inspections of any points where rainwater may leak, and try to use simple and effective technical methods Carry out waterproof technical treatment; during the construction phase of the project, it is necessary to avoid secondary risks to roof waterproofing.