Jiangmen steel Leakage Cause Analysis
1 design reasons: ① roof rainwater system failure to regulate an overflow measures when rainstorm intensity discharge capacity exceeds stormwater system will take over the seams, even Man on the roof, causing the accident; ② insufficient number of downspouts, rain gutter along the flow distance far away, a long time, resulting in backwater; external wall board did not receive additional L-shaped side member, causing the inside of the gutter leakage risks; ③ Color flashing accessories design is unreasonable, reach waterproof effect. ④ specification member deformation control value, purlin deflection L / 180, roof beam deflection L / 180 (where L is that span flexural members), roof purlins section design is too small, the pitch is too large, under wind loads purlins and pressure plate deformation becomes too large; ⑤ not fully consider the structural deformation, temperature deformation, shrinkage deformation, vibration, deformation fortification does not meet the needs of the grassroots. ⑥ portal frame light house roof slope should take 1/8 to 1/20, more rain in the area should take one of the larger value [4], the south roof slope should not be less than 5%. In the actual design project, many of the works of roof slope is too small, can not be routed to the roof rainwater gutters.
2 improper selection of materials: ① rainwater pipe with plastic pipe, poor strength, steel plant from installation to put into operation, easily damaged. ② relatively thin steel plates for gutter weld prone to problems. ③ not choose the right lighting panel according to the roof slope and roof color plate plate plate, smaller peak, side lap too, is not conducive to drainage. ④ color plates envelope portion is too thin, after a period of use, the outer plate corrosion or affected by temperature increases the gap between the deformed plate. ⑤ pressure plate substrate of poor quality zinc coating, the coating is too thin, causing the pressure plate life is short, easy to rust damage; ⑥ self-tapping screw pads poor quality prone to cracking, glass sealant is easy to aging. ⑦ pinch significant deformation, two adjacent plates plate high pitch are different; pinch pull nails should be used to waterproof rivets.
3 structural measures: ① plug due to leakage caused by the seam is action, should not be overlooked, such as guaranteeing color steel roof cover and plug in place between the plate and the roof covering plate lighting plug silicone sealant applied to play plastic, color steel roof opening at the peak end portion steel plug; ② when lapped joints easily affected by temperature increases should be sufficient enough to stay lap length; ③ water should not be blocked sparse, usually mounted inside the plate when playing sealant, the more the better; ④ must pay sufficient attention to the adverse effects of thermal expansion and contraction of the steel roofing envelope system, reasonable construction measures.
4 during use: ① on roof purlins be increased load, causing roof deformation. ② rain grate more contamination, the presence of water-blocking. ③ waterproof glue, sealant aging, lack of necessary maintenance during use.