Steel structure engineering is widely used in the field of super-tall and long-span structures. At present, leakage of steel structure roof is the most common quality fault, which will affect the use of buildings and cause economic losses. The following mainly from the design and construction aspects of steel structure roof leakage summarized the main reasons and commonly used anti-leakage measures.
The causes for the leakage
a.When designing the roof rainwater system, overflow measures were not set according to the requirements of the code. Therefore, after the rainwater exceeds the drainage capacity of the system, it may overflow the lap joints, resulting in leakage of the steel structure roof. Among them, the use of hidden buckle and nail board connected roof is likely to appear serious water leakage phenomenon.
b.The lack of detailed design drawings for the upper and lower eaves of the window, the flooding board of the roof ridge and the Yin and Yang Angle leads to the inexperienced construction team to be unable to strictly construct, resulting in leakage hidden danger.
c.The purlin has the design defects of too small section and too large spacing. Therefore, under the action of wind load, the deformation of the purlin and the pressure plate is too large, and the structural defects appear, which leads to the formation of water on the roof.
a.The gutter welding quality is not up to standard, the material anti-corrosion treatment is not in place, or the insulation measures under the gutter are not done well, thus causing the gutter leakage. At the same time, the temperature difference is large in summer, which is easy to produce the condensation phenomenon.
b.The wall purlin is not straight, there is a gap between the window frame or the window under the mouth and the steel structure, the window glass with the profile between the sealing problem, resulting in the water seepage of the window on the edge part, the window under the eaves appear water storage.
c.The construction of key nodes is not in accordance with the requirements of the construction or treatment is not in place, such as the short edge of the coil sealing head is not strict, the fixed point is rare, the upper mouth of the tin deformation, the sealing material is not good, the root negative Angle of the parapet is not made in accordance with the provisions of the arc or arc is too small, which leads to the roof leakage phenomenon.
Prevention and control measures
a.According to the characteristics of the steel structure roofing heat bilges cold shrink, the reasonable choice 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.
b.When designing, the roof rainwater system should be designed in strict accordance with the specification requirements, and overflow measures should be set. At the same time, the detailed drawings of the upper and lower cornice of the design window, the flooding board of the roof and the Yin and Yang Angle and other details should be supplemented to prevent the phenomenon of rainwater leakage.
a.Before the installation of the roofing panels, professional color plate pliers should be used to handle the flanging of the roofing panels. The height should be between 50~70mm, and the clearance between the roofing panels at the ridge should be guaranteed in the installation process for 50~100mm. At the same time, empty nails are strictly prohibited when fixing the roofing panels.
b.Gutter in addition to stainless steel material should be selected, after welding must also be closed water test, if found leakage must be repaired in time, at the same time can be increased in the gutter 150mm overflow device, so as not to rain along the gutter edge overflow to the room.
c.The connection between the brick wall and the light steel roof, in order to avoid temperature deformation, it is necessary to carry out two edge and connection processing, and in connection with the brick wall, the edge should maintain a certain Angle, and then implement complete sealing, and sealant should be used between the edge sealing.