Reasons and prevention measures of steel structure roof Water Leakage - Guangxi Xinfeng Steel Co. Ltd.
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Reasons and prevention measures of steel structure roof Water Leakage

Publisher:adminPublish time:2014-12-11Return to list

      Because at present our country steel structure construction technology is still in the exploratory stage of development and the reason of market competition, through the survey of steel structure building has completed construction of the steel structure building, built and put into use are Water Leakage phenomenon in different degree on the roof, roof Water Leakage has become the common quality defects of steel structure building.

1, steel structure roofing form

      Building roof as bearing and building envelope top enclosure, its role and elevation modeling is very important to the whole building, is an important part of the light steel structure bracing system most prone to Water Leakage. Its main role is to resist the invasion of the radiation and the solar wind, rain, snow, wind, snow and bear weight and roof roof and the human load [1]. Light steel structure roof used materials according to roughly the color steel plate, color steel sandwich panel, colorful shingles, various light roof panel, GRC board, arched corrugated metal roof, composite profiled steel sheet and other types of [2], light steel structure roof and wall materials mainly selects the color pressure plate or sandwich plates. Color pressure plate link has 3600 hemming plate, dark buckle lap connection, also hit the nail plate. Purlin for thin-walled C type or Z type steel purlin lighter weight, roof slope design is generally 1/10 ~ 1 /15.

2, roof plate connection

     Steel structure building roof panels on the roof has a long connection and two lateral connection. Long to connect is primarily a lap, namely the pressure plate up/down plate, put it set up the special waterproof sealant plus fixed special layering, and lateral connection ways mainly have the following three types: 2.1 lap connection; 2.2 hidden-interlocking type connection; 2.3 bite hidden-interlocking type connection;

3, cause analysis and solution of each part of leakage

       Roofing maintenance system leakage by part sums up mainly distributed as follows:

       The 3.1 part: the main reason of the parts of the roof Water Leakage is: at the ridge crest is too high, can not guarantee the waterproof roof cover plate; the longitudinal overlap does not put clay or silica gel, the formation of cracks and Water Leakage roof cover plate; the longitudinal overlap with rivet connection, thermal expansion and contraction strength is not enough snap rivet, formed between the cover plate and Water Leakage; roof roof panel laying plug, or plug placed not norm but falls off form Water Leakage. The solution is: do the roof cover plate is wide, the other slope looking for big point; take the junction of laying clay or silica gel; replace the suturing nail; should match the type board plug, plug should be laid on the devolution of clay or silica gel.

       3.2 roof monitor site: the area of leaky main reason is: monitor junction with the roof as not placed under a foam plug, and on the longitudinal lap not covered-with cement or silica gel; Roof plate in monitor junction not upper plate; Monitor structure Pillar opening parts do not make waterproof treatment; Monitor their own production, installation of the leakage risk. The solution is: on before installation should be equipped foam plug, longitudinal lap must set cement or plug and nail suture fixation; Monitor the installation Must be on the roof plate pull before; For construction of the monitor in monitor structure after the completion of the opening part must be waterproof processing; To monitor the installation quality and waterproof for inspection.

      The 3.3 part: lighting lighting plate slab and a roof panel type does not match, both sides of the crest above the roof panel lighting board, after installation, the sealing is too strict form lighting plate pressure difference between inside and outside, from both sides of the gap of capillary water lighting plate roof into the internal leakage of water; lighting plate longitudinal lap length of not enough, and the clay loses stickiness longitudinal aging; the clay off; rigid overlap between lighting board and color steel plate, the middle of the unsealed cracks. Water Leakage should pay attention to the following several aspects to prevent roof lighting board: Waterproof screw revaccination in wave upper; the receiving side plate lighting board office should be firmly sealed and lighting plate, vertical sides of clay to widen, and laying peak upper, prevent capillary water infiltration.

     3.4 roof opening position: the main reason of the site Water Leakage is: open hole not the design of node waterproof processing, steel plug placed without laying waterproof clay and silica gel; about the opening reserved smaller, rain water flows not free, easy to accumulate water; opening the wrapping around the lap did not enter for waterproofing treatment; opening internal around without structure, forming indentation seeper; waterproof construction existence water blocking, formation water. The solution is: according to the design drawings and the strict construction process, laying cement, silica gel; about the opening range must meet the requirements of the reserved drainage; walls, roof openings must be followed by waterproof processing; increase after opening as far as possible to add enclosure purlin or angle steel structure, reduce the enclosure deformation; waterproof construction installation must be tight, the water flow is smooth smooth.

      The 3.5 part: the cornice is the main cause Water Leakage problem, the main reason is: the site Water Leakage outside roof plate installed without foam plug, outside roof plate not lower wrench; the wall outside the plate length is insufficient, and the eaves parts without waterproof edge. The solution is: outside roof plate should be installed at the same time placed foam plug, and the outer plate pull roof under 30 degrees; eaves office should be designed according to the request for additional edge.

      The 3.6 part: the main reason of the gutter position is: Water Leakage gap exists in the welded joint, gutter formed seepage; gutter and rain water pipe diameter design is too small, long do not match the plant slope; the end part of the gutter didn't do the head plate; roof outer plate extends into the gutter insufficient length, the water will pour into the internal plant. The solution is: the depth appropriate to increase the gutter gutter, let rain does not exceed the lap seam.

      The 3.7 brick and the light steel roof connecting parts: the site is easy to form water leakage, roof panel and cement wall junction leakage, the main reason for the stress induced by non synchronous silicone sealant and adhesive surface cracking and leakage. Solution: to prevent the temperature deformation, using two times edge connection processing; connected with the brick wall, edge should have a certain angle, and completely sealed; edge should pre hit sealant.

Analysis of 4 other Water Leakage reason maintenance system

     4.1 reasons: 1. The design of roof rainwater system not according to specifications set overflow measures, the rainstorm intensity than rainwater system discharge capacity will exceed the joint, and even diffuse on the roof, causing the accident; the insufficient number of rainwater downpipe, along the gutter flow distance, time is long, made into a backwater; wall plate upper not adding L type the receiving side, resulting in the gutter medial Water Leakage hidden dangers; color flashing fitting design is not reasonable, is not up to the waterproof effect. The specification component deformation control value, purlin deflection of L/180, roofing beam deflection of L/180 (type L flexural members span), design of section of purlin roof is too small, the spacing is too large, purlin under wind load and pressure plate deformation is too big; without fully considering the structure, deformation, temperature deformation dry shrinkage deformation, the influence of vibration, does not meet the requirements of the basic deformation of fortification. Slope roof light housing the portal frame should be 1/8~1/20, [4] value should be greater the more rain area, south area roof slope should not be less than 5%. In the practice of engineering design, a lot of Engineering roof slope roof rainwater is too small, can not be timely discharged into the gutter.

    4.2 improper material selection: rainwater pipe with plastic pipe, poor strength, steel structure workshop from installation to operation, easily damaged. The gutter plate is thin, easy to appear the problem of weld. Third, not according to the profile plate lighting plate, choose the appropriate roof slope and roof color plate wave is smaller, lateral overlap too little, not conducive to the drainage. The retaining part color plate is too thin, after a period of use, the outer plate corrosion or affected by temperature deformation, increasing the gap between the plates. The bad press plate substrate quality galvanized layer, coating is too thin, resulting in the pressure plate and short service life, easy corrosion damage; the self tapping screw pad quality difference is easy to crack, easy aging glass sealant. The gusset plate obvious deformation, two adjacent plate high, spacing are different; buckle pulling nails should use waterproof pull nail.

     4.3 structural measures: plug due to the gap caused by leakage are, should not be ignored, such as the guarantee of color steel plate and roof cover plug installed in place, lighting board and roof cover between the plug lower revaccination silicone sealant, roof openings color steel plate wave is arranged on the end of steel plug; the lap when cracks easily influenced by temperature change is big, should be sufficient enough to stay the length of lap; the water should not be blocked sparse, general installation in plate medial sealants, Tado Masushan; the must pay enough attention to the adverse effects of steel structure roof enclosure system of thermal expansion and contraction, reasonable construction measures.

    4.4 the use of the process: the roof purlin arbitrarily increase the load, resulting in roof deformation. The rain grate dirt more, the existence of water resistance. The waterproof adhesive, sealant aging, lack of necessary maintenance in the use process.


      Factors causing the maintenance system Water Leakage steel structure have a lot, to fundamentally solve the problem, the need to design seriously, determine a reasonable design, do a head (head of the waterproof layer (two), joint deformation joints, dividing joint), port three (Shuila mouth, entrance, eaves) and four (daughter of Guan Daogen, the root wall, equipment, etc. Yan Conggen) flashing parts of the detail structure of processing [5]; from the construction, make the maintenance system of waterproof construction of special project, various professional coordination. Perfect design, installation in place, reasonable structure, used properly, service follow up, so as to ensure the maintenance of steel structure system leak. In short, whether to use any form of installation, as long as according to the construction process must and relevant regulations, can reduce or avoid the occurrence of Water Leakage problem.