Steel structure engineering is widely used in the field of large-span structures. At present, steel structure roof leakage is the most common quality problem. When it is serious, it will affect the use of the building and cause economic losses to the owner. The following mainly summarizes the main causes of steel structure roof leakage and common anti-leakage measures from the design and construction aspects for reference.
1. Reasons for leakage in design
(1) When designing the roof rainwater system, overflow measures were not set according to the specifications. Therefore, after the rainwater exceeds the system's discharge capacity, rainwater may overflow through the lap joints, resulting in leakage of the steel structure roof. Among them, the roof connected with concealed buckle and nailing board is very likely to have serious water leakage.
(2) The lack of detailed design drawings such as the edging of the upper and lower cornices of the windows, the flooding of the roof ridges, and the yin and yang corners have led to the inexperienced construction team unable to strictly carry out the construction, resulting in hidden leakage.
(3) The roof purlins have design defects that are too small in cross-section and too large in spacing. Therefore, under the wind load, the deformation of the purlins and the profiled plates is too large, and structural defects occur, which leads to water accumulation on the roof.
Design leakage prevention measures
(1) According to the characteristics of thermal expansion and contraction of the steel structure roof, the roof system is reasonably selected. Among them, the floating structure is selected as the roof structure, and the roof panel is locked by the bite type in the horizontal direction, that is, the vertical seam is locked, and the vertical direction is linked by sandwich extrusion At the same time, the lap length of the roof should not be less than 40mm, this structural system can slide, good sealing, good waterproof effect, strong wind resistance.
(2) When designing, the roof rainwater system should be designed strictly in accordance with the specifications, and overflow measures should be set. At the same time, the detailed drawings of the details such as the edging of the upper and lower cornices of the design window, the flooding plate of the roof ridge, and the yin and yang corners should be supplemented to prevent rainwater. Leakage phenomenon.
2. Causes of leakage in construction
(1) The welding quality of the gutter is not enough, the material anti-corrosion treatment is not in place, or the insulation measures under the gutter are not done, which causes the gutter to leak. At the same time, the temperature difference in summer is large, and condensation is easy to occur.
(2) Wall purlins are not straight, there is a gap between the same window frame, or there is a problem with the sealing between the lower opening of the window and the steel structure, and the same profile of the window glass, which leads to the seepage of the overflow edge trim of the upper window and the window Water appears under the eaves.
(3) The construction of key nodes is not carried out in accordance with the prescribed requirements or the treatment is not in place. For example, the short end of the coil is not tightly sealed, the fixing points are scarce, the upper iron sheet is deformed, the sealing material is not well sealed, and the female corners such as the daughter wall The arc is not made according to the regulations or the arc is too small, which leads to leakage of the roof.
Construction leakage prevention measures
(1) Before installing the roofing outer panel, the roofing outer panel should be flanged with professional color wrenches, and the height should be between 50 and 70 mm. During the installation process, the roofing between the roofing outer panels should be ensured The gap is 50 ~ 100mm, and it is strictly forbidden to hit the nail when fixing the outer panel.
(2) In addition to the choice of stainless steel for the gutter, a water-closing test must be carried out after welding. If leakage is found, repair welding must be performed in time. At the same time, an overflow device can be added at 150mm of the gutter to prevent rainwater from running along the edge of the gutter. Spilled into the room.
(3) At the connection between the brick wall and the light steel roof, in order to avoid temperature deformation, the edge trimming and connection treatment must be performed twice, and when connecting with the brick wall body, the edge trimming should be maintained at a certain angle, and then fully sealed, At the same time, sealant should be used to seal between the edges.