Referring to Metal Roof , I believe everyone is familiar with it, and it is now widely used in large-scale public construction projects and various factory buildings. However, metal roofs are easily affected by the weather. Once the waterproofing is not done well, rust, corrosion and other phenomena are prone to occur over time, which leads to water leakage problems. How to solve metal roof leakage?
Waste leakage in various parts and solutions
color steel plate maintenance system itself has a certain strength and stiffness, and the material generally does not leak water. The main reasons for water leakage in the maintenance system are improper processing at nodes, the quality of the material, the maturity of the system design, completeness, structural structure and installation technology, etc., all directly affect the waterproof effect of the enclosure system. When the color steel plate shrinks and deforms due to changes in the environment and temperature, when the interface and overlapping connections are displaced, ordinary sealant strips or silicone glue and color plate cannot be displaced simultaneously, causing water leakage on the roof of the color steel plate. Different lighting boards have different degrees of deformation and aging within the same time. The same nail boards are used, and the installation effects of different construction teams are also completely different. The main distribution of water leakage is as follows according to the location:
1, ridge
The main reason for water leakage in this area is: the peak at the roof is too high, and the roof cover cannot be guaranteed to be waterproof; the longitudinal overlap is not laid with waterproof, forming a gap and leaking; the longitudinal overlap of the roof cover is connected by rivets, and the thermal expansion and cold shrinkage strength is insufficient, which causes water leakage; there is no plugging between the roof cover and the roof panel, or the plugging is placed in irregular manner and falls off to form water leakage.
2. The main reasons for water leakage in this part are: there is no foam plug at the edge of the junction of the gas building and the roof, and the longitudinal overlap of the edge is not laid with waterproofing; the outer roof panel is not plated at the junction of the gas building; the opening of the pillars of the gas building structure has not been waterproofed; there is a hidden danger of water leakage in the production and installation of the gas building itself.
3, lighting board part
lighting board part waterproofing is an important part of maintaining the waterproofing of the system. The mud laying and waterproof screws in the lighting board installation are the main hidden dangers of roof leakage; the light board plate type does not match the roof plate type, and the peaks on both sides of the lighting board are higher than the roof panel. After installation, the seal is too strict to form an air pressure difference between the inside and outside of the lighting board, and capillary enters the inside of the roof from the gaps on both sides of the lighting board; the longitudinal overlap length of the lighting board is not enough, and the cement ages and loses its viscosity; the longitudinal mud falls off; there is a rigid overlap between the lighting board and the color steel plate, and the gap in the middle is not sealed, etc.
4. The opening of the roof hole in the roof must be to solve both the appearance and the roof waterproofing problem. Both problems must be determined based on the opening form and the model of the color steel roof panel. The main reasons for water leakage in this part are: the fan opening is not waterproof according to the design node, and the steel plug is not laid with waterproof; the reserved range around the fan opening is small, and rainwater flows smoothly, making it easy to accumulate water; the edge-to-edge overlapping of the opening is not waterproof; no structural parts are added around the opening, forming low concave water accumulation; waterproof construction has water blocking, forming water accumulation.
5,
The main cause of water leakage in the eaves. The main reason for water leakage in this part is: no foam plug is added to the roof outer panel installation, and no roof outer panel is pulled down; the wall outer panel is insufficient in length, and no waterproof edge removal is added to the eaves.
6, gutter parts
1 overlap joints and bridge joints are two key parts of water leakage. Compared with reinforced concrete roofs, the gutter depth of the steel structure roof is small, and there is no continuous waterproof structure between the gutter and the roof. When water accumulates in the gutter, it is difficult to ensure that there is no water leakage.The main reasons for water leakage in this part are: there are gaps in the inner gutter welded joint , forming seepage; the diameter of the gutter and rainwater pipes is designed too small, which does not match the slope length of the factory; there is no sealing board at the end of the gutter; the length of the outer roof panel extending into the gutter is insufficient, and water will flow back into the inside of the factory, etc.
7, Awning part
1 The main reason for leakage in this part is: the interface between the awning and the attached room is improperly handled; no plug is set between the awning and the exterior wall or does not extend into the exterior wall panel according to the design requirements.
8. The interface part of the factory and the attached house
The main reason for the leakage in this part is: the construction is unreasonable, and the interface edge installation does not meet the design requirements.
9. The connection part between brick wall and light steel roof
This part is prone to cause water leakage. Water leakage at the joint of roof panels and cement walls. The main reason is that stress is not synchronized, causing cracks and leakage in the bonding surface of the structural wall and the steel plate.
10, aluminum alloy window part
The connection part of aluminum alloy window and color steel wall and brick wall is one of the waterproof problems. The main reasons for water leakage in this part are: there is a gap between the wall purlin and the aluminum alloy; the seal between the lower part of the window and the steel structure, brick wall and window glass and profile is not strictly sealed; there is a large gap between the window sill and the table, or there is a phenomenon of backing back water; the upper part of the window is water-filled and edge-removed parts are not waterproof during the installation.
11, water leakage at roof screws and fasteners
This phenomenon is relatively common, mainly occurring in double-layer color steel plates and single-layer color steel plate roofs. During the construction process, the force of self-tapping screw is too heavy or too light, and the self-tapping screw is biased and oblique, etc. may cause the self-tapping screw rubber gasket to deform, fall off or form a concave surface, causing water leakage on the roof, and accumulate through insulation cotton , which accumulates in small amounts and forms a large point of water leakage. In addition, the position of the self-tapping screw is not correct, and the direct formation of holes is missed under the color steel plate and the holes are formed is also one of the important reasons for water leakage. This water leakage may not be obvious in the roof structure of single-layer color steel plates without insulation systems, mainly because rainwater leaks through the parts in contact with the steel plates and purlins and does not necessarily drip quickly.
12. Water leakage at the overlap between color steel plates
Horizontal overlap seams and vertical overlap seams. Water leakage at the overlap between color steel plates. If the tile wave of color steel plates is too low or the amount of rainfall exceeds the tile wave, it is easy to form a large area of water leakage, and it is not easy to detect leakage points, and it is difficult to repair once it is formed. Most commonly found in curved roofs. The main reasons are that the overlap between the two plates is not tight, the self-tapping screws are not fully punched, and the gap is formed, etc.
Other causes of water leakage
1. Design reasons
(1) The roof drainage system does not set overflow measures according to the specifications. When the intensity of the heavy rain exceeds the discharge capacity of the rainwater system, it will exceed the overlap seam, and even overflow the roof, causing accidents;
(2) The number of downspout pipes is insufficient, and the rainwater flows along the gutter for a long time, causing to be blocked by water; no L-shaped edge-retraction parts are added on the upper part of the outer panel of the wall, causing a hidden danger of water leakage on the inner side of the gutter;
(3) The design of color steel water-flow accessories is unreasonable and cannot achieve waterproof effect.
(4) Specifications stipulate component deformation control values, purlin deflection L/180, roof beam deflection L/180 (where L is the span of the bending member), roof purlin cross-section design is too small and the spacing is too large, and under the action of wind load, the deformation of the purlin and press-shaped plate will be too large;
(5) The impact of structural deformation, temperature difference deformation, dry shrink deformation, vibration, etc. is not fully considered, and the fortification does not meet the needs of base layer deformation.
(6) Door type rigid frame light house roof slope should be 1/8~1/20. In areas with more rain, the larger value should be taken. The roof slope of southern area should not be less than 5%.In actual design projects, the roof slopes of many projects are too small, and the roof rainwater cannot be discharged into the gutter in time.
(7) There is a phenomenon of backflow of water in the awning design, causing water leakage in the awning area;
2. Improper material selection
(1) Use plastic pipes for rainwater pipes. The strength is poor, and the steel structure factory is easily damaged from installation to production and operation.
(2) Because the steel plate gutter is relatively thin, welds are prone to problems.
(3) The appropriate lighting panel type and roof color panel type are not selected according to the slope of the roof. The peaks are small and there are too few lateral overlaps, which is not conducive to drainage.
(4) The color plates in the enclosure are too thin. After a period of use, the outer plates will corrode or be deformed due to temperature, and the gaps between the plates will increase.
(5) The galvanized layer of the press-type board substrate is poor and the coating is too thin, which causes the press-type board to have a short service life and is prone to rust and damage;
(6) The quality of the self-tapping screw pad is poor and it is easy to crack, and the glass sealant is prone to aging, etc.
(7) buckle plate is obviously deformed, and the plate heights and spacing of the adjacent two boards are different; the buckle plate pulling nails should be waterproofed.
3. Structural measures
(1) The plug is effective for water leakage caused by wind and should not be ignored. For example, ensure that the plug of color steel plate and roof cover plate is installed in place, the lower part of the plug between the lighting plate and roof cover plate is strengthened, and the steel plug is installed at the end of the color steel plate peak at the roof fan is installed, and waterproofing is strengthened;
(2) When overlapping, the gap is easily affected by temperature, and sufficient overlap length should be left;
(2) When overlapping, the gap is easily affected by temperature, so sufficient overlap length should be left;
(2) When overlapping, the gap is easily affected by temperature, so sufficient overlap length should be left; 2
(3) Water should be drained rather than blocked. Generally, when installing, sealant is applied on the inside of the steel plate, the more the better;
(4) You must pay enough attention to the adverse effects of thermal expansion and contraction of the steel structure roof enclosure system, and take reasonable structural measures:
4. Improper use
(1) Loads are added at will on the roof purlins, resulting in deformation of the roof panel.
(2) Rainwater castor accumulation is high, and there is water blockage.
(3) waterproof glue . Sealant aging, and necessary maintenance is missing during use.
