What is the cause of water leakage on the steel structure roof?
Hidden dangers of water leakage caused by house structural design or board shape defects
1. The color plate on the roof of the steel structure is too thin. After a period of use, the outer plate is corroded or deformed by temperature, and the gap between the plates increases, resulting in water leakage.
2. Improper selection of plate type. For the plate type directly connected with self-tapping screws, even if the site is well handled and the waterproof glue is in place, water leakage will occur due to the thermal expansion and contraction of the panel.
3. In the fierce market competition, the construction party blindly lowers the construction cost in order to undertake the task. In order to save raw materials, the slope of the house is reduced in the design of the steel structure roof structure, and some are even lower than 1/20, causing the roof rainwater to not be discharged to the gutter in time, causing the roof to accumulate water and causing the house to leak.
4. Due to the cost factor, most of the profiled panels used in light steel houses at present are panels with low slope heights, and the lap width is small. When water accumulates in the house, it is easy to overflow the overlapping parts of the plate type, resulting in water leakage.
5. Lack of node design, the construction unit randomly chooses the node method, the height of the parapet wall at the ridge of the steel structure roof is not enough, and the position or height of the pipes and exhaust ducts protruding from the roof is not appropriate or the height is not enough, so that the construction of the waterproof layer is difficult and water leakage occurs.
Water leakage hazard due to material properties
1. Special parts: due to the use of different materials for connection, such as the connection between the parapet and the steel plate, the roof lighting belt and other parts, the hidden danger of water leakage is caused by the asynchronous stress change.
2. In the steel structure system, because the structure itself is prone to elastic deformation under the action of external forces such as temperature changes, wind loads, and snow loads, displacements occur at the connection parts, resulting in hidden dangers of water leakage.
3. The thermal conductivity of the metal plate itself is large. When the external temperature changes greatly, due to the large change in the ambient temperature difference, the color steel plate shrinks and deforms due to the temperature change, resulting in a large displacement at the interface. Therefore, the hidden danger of water leakage is easy to occur at the interface of metal roof slabs on steel structure roof.
Potential water leakage caused by construction factors
1. During the construction process, the steel structure roof enclosure is not paid attention to protection, and the roof is stepped on at will, which destroys the flatness of the roof and even cracks.
2. The gutter is not anti-corrosion. The gutter anti-corrosion of some construction units is only painted with anti-rust paint or asphalt paint, and the gutter corrodes seriously after a period of use.
3. Due to the large span of the roof panel of the steel structure factory, in many cases, there is an overlapping process of the roof panel. Although polyurethane sealant and sewing nails are used at the overlapping joints, the installation is often difficult to meet the design theoretical standards, resulting in rain leakage .
4. There is no slope in the horizontal direction of the gutter. Leave a certain slope during production, at least 0.5.
5. The construction of key nodes is sloppy. The inner corner of the root of the wall is not made according to the regulations or the arc is too small, the short side of the coil is not tightly sealed, the upper white iron sheet is deformed, the fixing points are scarce, and the sealing material is not well sealed.
