(1) design of roof rainwater system did not set the relief measures in accordance with the specification requirements, therefore rainwater discharge capacity beyond system may appear after the rain over lap seam phenomenon, resulting in steel structure roofing leakage phenomenon.In this case, there is a possibility of serious leakage in the roof of the roof connected by the use of the buckle and the nail plate.
(2) the window up and down the eaves of the roof of the water board and side Angle of Yin and Yang details such as the lack of detailed design drawings, lead to lack of experience of construction group cannot be strict construction, resulting in leakage hidden trouble.
(3) roof purlin section is too small and too much spacing design flaws, so that under wind load, purlin and deformation of the pressure plate is too large, structural defects, resulting in roof water is produced.
(1) cullis welding quality closes nevertheless, anticorrosion material handling does not reach the designated position, or not be installed under the heat preservation measures, resulting in leakage of roof gutter, at the same time, the summer temperature difference is bigger, is easy to produce condensation phenomenon.
Purlin is not straight, (2) the metope with window frame between the gap, or between mouth and steel structure under the Windows, Windows with profile between the sealing problems, leading to window head flashing as pieces appear ooze water, a water window under the eaves.
(3) construction key nodes not carried out in accordance with the specified requirements or processing does not reach the designated position, such as coil short side head untight seal, fixed point scarce, flowing deformation of tin, sealing material sealing is not good, parapet and so on root Yin Angle make arc or too small, not according to stipulations and lead to roof leakage phenomenon.
Prevention and control measures
(1) according to the characteristics of the steel structure roofing heat bilges cold shrink, choose the roofing system, including roof structure choice floating roof, roof plate transverse to bite type lock close, namely straight seam side whipstitch, longitudinal sandwich extrusion way links, and roof lap length should be no less than 40 mm, this system can be sliding structure, good sealing, waterproof effect is good, strong ability to resist wind.
(2) the design should be in strict accordance with the specification requirements design roof rainwater drainage system, and set the relief measures, at the same time complementary design window eaves bag up and down side, the roof of the water board and Yin and Yang Angle and so on the details of the detailed drawings, preventing water leakage phenomenon.
(1) in the roof plate before installation should be adopted professional color plate clamp was carried out on the roof plate flanging process, its height should be between 50 ~ 70 mm, and the installation process shall ensure that the roof in the roof of the gap between plate for 50 to 100 mm, fixed plate at the same time it is forbidden to punch pin.
(2) installed in addition to should choose stainless steel material, after the welding must be closed water test, if found leakage shall promptly repair welding, at the same time can increase the overflow device 150 mm in the gutter, lest the rain along the gutter margin to indoor.
(3) the brick wall with light steel roofing joints, to avoid deformation temperature, shall be for the first of two side and the connection handle, and the connection with the brick wall, make the edge should maintain a certain Angle, and then execute completely sealed, at the same time as sealant should be adopted to seal.