Solution to the leakage problem of plastic inner casement window

From the analysis of the simple principle of water circulation, the solution to the leakage of the plastic inner casement window can be simply attributed to the two words "blocking" and "sparse". Blocking means to improve the sealing degree of the inner opening window as much as possible, and block rainwater outside the window to reduce the amount of infiltration. Of course, in fact, no window can be truly sealed, and there are too many factors that affect the sealing of the inner casement window. Therefore, the problem of dredging the last line of defense for rainwater entering the room must be solved in a relatively sealed situation, and the rainwater between the frame and fan should be discharged in time. Let's discuss with you how to solve the leakage problem of the plastic inner casement window.

2.1 Scientifically standardized plastic inner casement window design

To solve the root cause of the rainwater leakage problem of plastic inner casement windows, we should start with the design of doors and windows, the most important of which is the design of water tightness and wind pressure resistance. The water tightness does not need to be explained, and the wind pressure resistance is directly related to the leakage problem, including in coastal areas with high wind pressure, including high-rise buildings in various places, the root cause of leakage is often due to the unreasonable wind pressure design, and the window design is not easy to pass. Due to the large wind pressure, the deformation of the force-bearing members of the doors and windows will lead to leakage, which can meet the maximum wind pressure requirement once in 30 years. The design of doors and windows involves many problems and will not be described in detail here.

2.2 Measures to avoid rainwater leakage during installation

Rainwater leaks into the room from the lower eaves of the window frame, which is generally caused by improper installation of doors and windows. Due to the large difference between the expansion coefficient of plastic profiles and walls, a reasonable gap between the door and window and the opening must be ensured during the installation of the door and window. At the same time, the gap must be used. Elastic material (currently mainly using foaming agent) is filled, and the gap between the decorative surface of the wall and the window frame is sealed.

Waterproof sealing treatment must be done between the window frame and the auxiliary profile of the inner casement combination window. Generally, transparent glass glue is used for sealing, while ensuring the aging performance of the sealant.

2.3 Selection of sealing strips for inner casement windows

The glass, profiles and openings of the fixed part of the plastic inner casement window are relatively sealed by the sealing tape. The structural design of the sealing tape and the quality of the tape directly affect the water tightness of the window. The sealing tape The structure is scientifically designed based on the profile structure and improved sealing performance, and the quality of the sealing tape mainly includes material, aging performance, UV resistance, toughness, thickness, etc., to ensure long-term service life. The following is an example for analysis and explanation.

The importance of the structure of the sealant strip:

A. Choose different resultant rubber strip structure for different profile assembly parts

Generally speaking, K-type structural rubber strips are used on the layering strips, and O or OK-type structures are selected for the matching part of the frame fan. Of course, a reasonable choice should be made according to the specific structure of the profile, especially the multi-layer sealing structure. The middle part of the sealing strip is based on The specific structure of the profile is designed for the specific structure.

B. Design a more scientific rubber strip structure

1) After selecting the basically correct type of rubber strip structure, the sealing performance of the inner window can be improved by designing a new rubber strip structure. Here are several ideal rubber strip structures (note: two of them are self-made by Zhongcai Profiles). design).

2) The quality of the sealing tape: From the current point of view, it is more reasonable to choose high-quality EPDM tape. Brand sealing tape manufacturers should be selected to ensure the long-term service life of the sealing tape.

3) Precautions for installation of sealing tape

From the actual windowing effect and our many years of experience, the corners are often the rainwater leakage point of the window. The installation quality of the sealing tape at the corner directly affects the sealing performance of the window. Each sealing tape should be located at the end In the middle of the upper edge of the profile, the sealing strip at each corner should be cut with 89° rubber strip to make the rubber strip flat at right angles. It is strictly forbidden to cut the tape. At the end interface of the sealing strip, a margin should be left at most 1% longer than the length of the strip groove to prevent the strip from shrinking. Align the broken ends of the rubber strips tightly and bond them firmly with glue.

2.4 Reasonable design and processing of drainage holes and air pressure balance holes

1) The inside and outside of the drainage hole should be punched out of position. The inside and outside drainage holes are easily staggered by 50~60mm to improve the air penetration inside and outside the profile cavity to ensure smooth drainage and increase drainage;

2) The size of the drainage holes is generally 6*30mm, and the number of drainage holes is determined according to the size of the window type. The spacing of the drainage holes on the same side should not be greater than 800mm;

3) It is necessary to install the outer drain hole cover to slow down the phenomenon of rainwater directly from the drain hole caused by wind pressure;

4) When the drainage hole is processed, the air pressure balance hole should be processed to ensure air circulation in the inner cavity of the door and window, which is conducive to the discharge of rainwater.

2.5 Selection of high-quality plastic inner casement window hardware

The seal between the plastic inner window sash and the frame is mainly locked by hardware transmission, so the effect and strength of the hardware locking are directly related to the possibility of rainwater leakage, and at the same time, the actual locking effect and the hardware after the deformation of the profile under strong wind pressure are ensured. For the guarantee of the locking function after long-term use, we need to pay attention to the following requirements or suggestions for the inner casement hardware:

1) You must choose the inner flat hardware products produced by the brand hardware manufacturers, and the quality of the hardware raw materials must be guaranteed, so as to ensure the long-term use of the hardware products.

2) Choose hardware product specifications that complement the profile structure. For example, 9/13 series profiles must be matched with corresponding hardware, especially for door and window systems developed by various manufacturers, such as Zhongcai profiles. We recommend choosing Zhongcai door and window hardware.

3) In the case of high-rise buildings, typhoon areas, or large opening area of the inner opening fan, we recommend using multi-point locking inner opening hardware (increase the upper and lower ends of the inner opening window to lock).

2.6 Standard quality control of door and window assembly is also an important part of solving leakage problems

Every aspect of the assembly involved in cutting from profile cutting to glass assembly should have a more or less impact on the water tightness of the inner casement window. For example, the cutting of profile cutting affects the size of the window and affects the final sash overlap. Affecting the sealing performance, the installation of the sealing strip and the corner treatment directly affect the water tightness, and the installation of the corner hinge also directly affects the sealing performance of the window. For this, it is necessary to control the assembly quality to ensure the water tightness of the inner casement window. Door and window assembly technology is also a part of the system doors and windows. According to the technical design requirements of different doors and windows, the corresponding door and window processing guidelines are formulated. At present, the Zhongcai Door and Window Group Installation Technical Manual that we are compiling is to carry out this work.

2.7 Other aspects

1) The upper edge of the window frame is decorated with water strips so that rainwater from the upper part of the doors and windows can be drained out of the windows through the water strips. At the same time, it is easy to form a rain curtain effect, which is conducive to rainwater discharge.

2) The inner open fan is designed with a water eave structure, which is conducive to the smooth discharge of rainwater inside the fan to the drainage hole in the frame.