The leakage of aluminum alloy doors and windows in construction engineering has troubled the door and window factory for many years, but there has been no good way to solve it at one time. Many experts have given many cause analysis and treatment plans before, next, we will analyze and discuss the different leaking parts of aluminum alloy flat doors and windows.
I. Leakage at the corner of the outer frame
at present, there are two ways to connect the outer frame of aluminum alloy on the market: 45 degrees set angle and 90 degrees straight thread fastening. Among them, the 45-degree angle is aimed at the structure of the profile with cavity, and the synchronization between the 90-degree straight frame with closed injured body and without it is applicable.
Causes of 45 degree Group angle leakage and treatment plan:
1. When blanking, the 45 degree blanking angle is wrong or the cutting saw blade is seriously worn and the dynamic balance is not good, resulting in gaps or concave defects at the 45 degree angle, resulting in leakage; Treatment plan: improve the blanking accuracy of the equipment and often replace the saw blade;
2. When the angle is set, the matching gap between the angle code and the frame profile is too large, resulting in looseness or gap in the 45-degree splicing after the angle is completed, resulting in leakage; Treatment plan: it is suggested that the matching gap between the angle code and the profile cavity should be controlled within 0.2mm, and the force point of the angle code at the cooperation of the squeezing knife should be added to the reinforcement support;
3. When the 45-degree angle is set, the 45-degree section is not coated with sealant, resulting in water flowing directly into the cavity along the 45-degree section and penetrating into the wall; Treatment plan: before setting the angle, apply the rinse sealant on the 45-degree section, preferably a sealant with certain extensibility and elasticity;
4. After the set angle is completed, no sealant is injected into the cavity of the set angle, resulting in insufficient overall strength and sealing of the corner, which will directly penetrate into the corner when there is water; Treatment plan: after the set angle is completed, before injecting the seal into the cavity at the corner, it is best to polyurethane two-component corner glue. Because this glue is two-component, it does not need to absorb moisture from the air during the drying process, and it will also dry in a sealed environment, at the same time, this glue is hard glue after drying, which improves the strength of angle by 3~5 times, and the sealing property is extremely ideal;
5. There is no treatment in the cavity of the insulation part of the Broken Bridge insulation profile, causing water to directly enter the corner from this section and seep out; Treatment scheme: design a connector dedicated to the cavity of the insulation strip, and sealed with glue injection;
6. The connection angle plug-in is not installed at the flanging of the large surface of the profile (especially when the doors and windows are opened inside). Because there is no angle code here, there is dislocation or gap, causing water leakage; Solution: design a connection angle plug-in with corresponding slot, and inject glue at the corner;
causes of 90 degree Group angle leakage and treatment plan:
1. There is no soft double-sided adhesive tape on the splicing surface when the horizontal and vertical frames are spliced, resulting in gaps at the splicing site and leakage of water; Treatment plan: paste affixed double-sided adhesive tape or design an adhesive connector at the splicing site. After the connection is completed, the adhesive is injected to seal the joint;
2. The design of the cross-section structure is unreasonable, and the uneven distribution of the fastening points of the screws causes uneven force during fastening, resulting in gaps; Treatment scheme: change the cross-section structure to make the force uniform when the screws are fastened;
3. Fastening screws is too short, resulting in insufficient stress, and the frame is easy to twist and there is a gap; Solution: replace the screw specification, and pay attention to the matching tolerance between the diameter of the screw used first and the fastening hole of profile screw tightening.
II. Leakage at the bottom of the frame and fan
open doors and windows from the inside and open doors and windows from the outside are two ways to open.
Cause analysis and treatment scheme of leakage in the lower mouth of the frame and fan matching of aluminum alloy open doors and windows:
1. The overlapping amount of frame and fan is not enough or uneven. Ideally, the overlapping amount of frame and fan is 6 ~ 8mm, if it is too small, in addition, the thickness of the flanging of the large surface is not designed as a variable cross-section structure. When there is wind pressure, leakage will occur at the matching Place. For example, the principle is the same if the overlapping is uneven. Solution: If it is a design problem, the design plan needs to be adjusted. If the overlap is uneven, the hardware is used to adjust the upper, lower, left and right, at the same time, check whether there is any problem with the size calculation method of the blanking document;
2. The matching gap of the sealant strip at the overlap of the frame and fan will affect the effect of the adhesive strip used together. During normal design, the fit gap of the sealant strip at the overlap of the frame and fan is 3.5mm ~ 5.5mm. When it is small, the installation channel of hardware will be affected, which will cause the whole fan to the outside, as a result, the actual effective deformation of the strip is not enough. When it is too large, the overall thickness of the strip is relatively large, and the material of the strip itself is relatively soft. When the thickness is relatively large, it should be considered, the rotating torque of the handle during closing will have a great influence on the sealing performance of the adhesive strip, especially when there is wind pressure, it will be more likely to leak water; Treatment scheme: if the reason for the design gap, redesign the size of fit gap; If the design time-varying type of adhesive strip is not enough, redesign the adhesive strip, the deformation of general adhesive strip is recommended to be 1.5~2mm;
3. The soft hardness, material of the selected strip and whether there are shrinkage and exposed joints at the end of the strip are also the causes of leakage; Treatment plan: determine the reasonable soft hardness of the strip, the strip is not cut off at the corner of the end of the strip, or connected with dedicated rubber bar adhesive. At the same time, 10~20m length should be reserved when installing the strip to prevent the strip from aging and shrinking;
4. Water seeps down from the fastening screws matching gap, and then seeps out from the corner of the group; Solution: When tightening the screws, first use the cross pre-drilling Confucius, after that, sealant is injected into the hole, and then screw fastening is carried out to ensure that glue is sealed in the matching gap between the screw and the profile;
5. The rationality of hardware matching with frame and fan slot. If the hardware matching with profile slot is unreasonable during design, it will cause the clearance of frame fan and the clearance of hardware matching slot to change, so as to affect the effective sealing performance of the rubber strip and cause leakage; Treatment scheme: when designing the product, the cooperation between hardware and profiles must be comprehensively considered, and hidden dangers must be eliminated in the design stage;
6. No isobaric cavity is set. When the wind pressure is large, water will enter the hardware installation coordination place of the frame and fan from the outdoor side. Due to the high wind pressure ratio coordination place of the outdoor side, water cannot be discharged to the outdoor all the time, when the water reaches a certain height, it will enter the room, causing leakage; Solution: set equal pressure chamber, including frame fan coordination and open fan;
7. The setting of Rhone and the design of drain hole cover structure. If Rhone is not set, water cannot be discharged out, but if Rhone is not reasonable drain hole cover, not only water cannot be discharged, but also wind will blow in from Rhone, cause bubbles; Treatment plan: set rhone, rhone can not only consider the slot on the most outdoor side, but must simultaneously consider the drainage of aluminum ribs in the middle of the profile, and reasonably design the drainage confucius cover, it is required that when the outdoor wind pressure is greater than indoor, the automatic locking function can be realized.
Cause analysis and treatment scheme of leakage in the lower mouth of the frame and fan matching of aluminum alloy inside doors and windows: the leakage phenomenon in the frame and fan matching of aluminum alloy inside doors and windows is basically the same as that of outside opening, only in the open doors and windows, there is a seal of a large duckbill rubber strip. When designing this rubber strip, we must fully consider the lap amount of the rubber strip and the compression deformation of the rubber strip, it is suggested that the lap amount of this strip and aluminum profile should be 3.0~3.5mm and the deformation should be 1.5~2.0mm.
3. Leakage at the joint of the middle end
at present, there are two common connection modes: direct fastening connection with 90-degree screws and connecting and installing with middle-end connectors;
there are also two ways to deal with moderate waterproof leakage: one is blocking, the other is sparse, that is, drainage. We make some analysis on leakage from the idea of blocking:
leakage of 90-degree screw direct fastening connection:
1. There are two ways to process the middle end: 90-degree flush blanking and profiling processing, no matter which end processing method, the splicing joint of the middle end needs to adopt soft material for buffer sealing. If it is not used, the sealing here is very poor. If there is water, it will flow directly through this gap, after emerging from the indoor side; Treatment scheme: design a soft sealing film with the structure matching with the profile breaking surface, which plays a sealing and buffering role when it is installed;
2. Whether the specifications and sizes of the selected screws are reasonable. Small or short screws will cause insufficient rigidity connection, easy to loosen, easy to appear gap, easy to penetrate when there is water; Solution: choose reasonable screws with material and specification size;
3. Match gap treatment with corresponding matching profiles after end milling of medium and large surface. The gap here is generally 2~4mm. If it is not processed, it will directly become the water inlet. Especially when the outdoor negative wind pressure occurs, the gap between the frame and the fan is enlarged, and the water inflow becomes larger, finally, it will directly cause indoor side leakage; Treatment scheme: design a matching plastic part, and after installation, inject glue into the cavity on the opposite side of the plastic part for sealing.
Leakage by connecting the middle joint:
1. The matching between the mid-rise connector and the mid-rise cavity is too loose, resulting in looseness between the mid-rise connector and the matched outer frame after the mid-rise is installed, and there is a matching gap, resulting in water seepage; Treatment plan: when designing the scheme, the matching gap between the two should be considered, and it is generally suggested that the matching gap between the two should be within 0.2mm;
2. Whether the position of pin locking positioning hole is offset. If the position of the pin locking locating hole is too small, it will cause the pin not to be locked after fastening, causing the middle part to loosen and eventually causing leakage; Treatment plan: when compiling the processing technology, pin locking hole position should be correct, at the same time using die processing, avoid using pistol drill manual processing;
3. After the installation is completed, no sealing treatment is carried out, resulting in water leakage from the coordination place; Treatment plan: after the installation is completed, inject appropriate sealant into the coordination place, the best is polyurethane two-component corner glue, which not only ensures the sealing performance, but also increases the connection strength;
4. Match gap treatment with corresponding matching profiles after end milling of medium and large surface. The gap here is generally 2~4mm. If it is not processed, it will directly become the water inlet. Especially when the outdoor negative wind pressure occurs, the gap between the frame and the fan is enlarged, and the water inflow becomes larger, finally, it will directly cause indoor side leakage; Treatment scheme: design a matching plastic part, and after installation, inject glue into the cavity on the opposite side of the plastic part for sealing.
IV. Leakage at the cooperation between aluminum alloy frame and the Wall
1. The installation gap between aluminum alloy frame and the opening is too small or too large. The filling material cannot be filled in place when it is too large. When it is too large, the filling material cannot be filled in, which will cause leakage; Solution: first of all, the reserved clearance of the four surrounding areas should be fully considered when checking the size of the opening. For rear installation, it is generally recommended to reserve a matching clearance of 7~10m unilaterally. Secondly, when installing on site, the gap between the lower, left and right is basically adjusted evenly to prevent the situation that one side is big and the other side is small;
2. Selection of filling materials. At present, the filling materials used between aluminum alloy frame and the opening are mainly waterproof mortar and polyurethane foaming agent. The selection of waterproof mortar label is unreasonable, which will cause the expected waterproof effect not to be achieved; the selection of unqualified polyurethane foaming agent (such as the density, expansion time, waterproof and other properties after expansion are not up to standard) will also cause leakage; Treatment plan: select appropriate waterproof mortar and foaming agent;
3. Whether the temporary positioning and load-bearing cushion blocks are folded and filled with filling materials after the doors and windows are installed. The cushion block used for on-site installation of doors and windows is temporarily used. After the installation of the window is completed and the filling material has been used, the cushion block should be removed, and the filling material should be filled in the folded part, otherwise, leakage will be caused; Treatment plan: remove temporary locking block and fill in filling materials;
4. Sealing treatment at the matching place of outdoor side aluminum alloy frame and wall. The sealing materials on the outdoor side are generally silicone sealant, the selection of sealant and the thickness of glue, etc., which will directly affect the water tightness. One of the poor glue is poor compatibility and adhesion, at the same time, it is easy to crack after the glue is dried. If the glue is thin, it will also crack, which will cause leakage; Treatment scheme: select the appropriate sealant, at the same time, it is recommended that the thickness in the middle of the glue should not be less than 6mm when the glue is added;
5. When installing the iron feet, it is not recommended to use fastening screws to connect the iron feet with aluminum alloy frame at the lower mouth of doors and windows. Screws are used at the following mouth, then there is a hidden danger of water leakage at the cooperation between the screw and the aluminum frame; Solution: Use insulation displacement connection-type iron feet;
6. Leakage caused by non-doors and windows. As the general contractor or other external wall construction units are not in place during the construction of the waterproof treatment caused by more leakage, this will not be discussed here.
A good aluminum alloy door and window product consists of at least three parts: complete design scheme, perfect production process, manufacturing equipment and qualified staff, reasonable on-site installation process and qualified installer. As long as one of these three parts is not done properly, it will cause many quality risks.
