In the actual use of the glass curtain wall, water leakage is the quality problem that the owner can directly feel and the most daily troubles. It has become one of the most common ills in the glass curtain wall for many years.
The reason for the water seepage of the glass curtain wall is very complicated. It involves various aspects such as design, material application, construction and management. It is necessary to strengthen research, formulate effective measures, and comprehensively control and prevent problems before they occur. Below we analyze the main causes and solutions of several common curtain wall leaks.
First, the roof glass curtain wall leaks
The xx brigade building in the central area of Shenzhen, which was first opened in August 2009, was only opened for half a month. In the heavy rain of the typhoon “Molafi” on July 19, 2009, the roof of the glass curtain wall leaked, and the indoor leakage was similar. Light rain, the room was leaked and "wet", showing the degree of water leakage.
According to preliminary investigations, the leak should be insufficiently sealed at the back of the glass curtain wall above the roof. The main body of this building is a unitized curtain wall, which is higher than the frame-type glass frame wall with a glass curtain wall of about 20 meters from the roof. From the scene view, the main reason is that the connection at the back of the glass curtain wall is not sealed enough, it depends on the rubber strip. Sealed, rainwater leaks from the sealant strip to the beam and then flows down the aluminum main column.
Later, the management office arranged a thick sealant on the back of the rubber curtain wall of the worker's glass curtain wall. As a result, there was a slight rainwater leakage in case of heavy rain. It may be caused by the leakage of rainwater from the exposed glass curtain wall. The most thorough solution for the roof glass curtain wall should adopt the disconnected waterproof construction measures.
Second, the exposed glass curtain wall leaks
This is a typical bright-framed glass curtain wall node. In actual engineering, there will be slight water leakage. The main reason is that the aluminum compact is generally made of 50mm in length and placed one at a distance of 350mm. The aluminum decorative line is generally 1.5mm thick. At the cloud marking, the aluminum moldings Gluing between the glass and the glass, because there are no aluminum briquettes and strips under some positions, the glue should not be able to effectively control the quality. After one or two years, the sealant is prone to cracking and other problems, causing the curtain wall to leak and breathe!
Solution: The aluminum briquettes should be long, effectively controlling the quality of the glue; secondly, the gap treatment method of using sealant and tape is promoted.
Third, the glass curtain wall can open part of the water leakage
The opening window of the xx brigade building project in the central area of Shenzhen is the 70 series of hook-type hidden frame hanging windows. The window locks use multi-point locks. On average, each window sash has 5 full locking points and evenly distributed locking points. When the sash is evenly pressed, the sash is pressed forcefully, so that the sealing strip to the window has a certain degree of uniform compression. It can be said that the opening window in this state, although it is better in water tightness, is still There is a slight water leak.
1). According to the principle of equal pressure waterproofing, a compression type water-blocking sealing strip is arranged at the top of the window, so that the rainwater directly contacts the sealing strip of the opening window, thereby further effectively improving the watertightness of the opening window. .
2). Carefully use the hook-type hidden frame to suspend the window. Many people will not use the wind bracing, so that they will try their best to pull the wind bracing, and the limit block on the window will be broken, and the whole glass opening fan will fall to the downstairs. Start.
3).the lower part of the glass frame curtain wall window is also a key part of water leakage prevention. It should be filled with aluminum alloy and embedded with rubber strip to seal the rubber. The second is to open the glass tray at the lower end of the fan glass to avoid the structural glue being subjected to gravity.
Fourth, the unit glass curtain wall leaks
1. Three sealing lines for the unit curtain wall
(1) Dust line.
A sealing line designed to block dust is generally achieved by overlapping the strips of adjacent units to block dust and water. This seal line may not be designed in the South.
(2) Watertight line.
It is an important line of defense for the unit curtain wall. A small amount of water leakage through the surface of the curtain wall can pass through this line and enter the isobaric chamber of the unit curtain wall. Through reasonable structural design, the water entering the isostatic chamber will be discharged systematically without continuing to enter the room. The ability to achieve water blocking purposes. Sometimes in order to improve the watertight performance of the curtain wall, it is also possible to set multiple watertight lines at the same time.
(3) Airtight lines.
It is also an important line of defense for the unit curtain wall. Since the isobaric chamber between the watertight line and the airtight line is basically in communication with the outside (sometimes a dust-proof sponge is placed on the communication hole), the watertight line cannot prevent the air from penetrating. The task of preventing air infiltration is done by the last line of defense - airtight lines.
2. Analysis of waterproof mechanism of unit curtain wall
In the surface of the curtain wall, in order to waterproof the rain curtain principle, the pressure Pc of the isostatic chamber is designed to be equal to or close to the outdoor pressure Po, that is, the wind pressure on both sides of the watertight line is substantially equal, eliminating or reducing the effect of the wind pressure, so that the water is not Enter the isobaric chamber with or little through the dust and watertight lines.
On both sides of the airtight line, the gap and the action are also unavoidable. To achieve the purpose of no leakage, the water should not be drenched to the airtight line, and the water in the three elements of leakage should be eliminated, due to the dust line and watertightness. There is little or no water in the line, and with reasonable tissue drainage, there is no water to the airtight line. There is no water around the gap of the airtight line, so there will be no leakage, so that the unit curtain wall has a good insertion position. Waterproof ability.
The weak link of the unitized curtain wall waterproofing is the “+” character seam of the four units, which is the key to the successful waterproofing of the unitized curtain wall. At present, the more successful solutions include horizontal sliding type and “+” cross-sealing structure. I won't go into details here.
In the actual project, the "cross-lock" unit curtain wall has to use the "plug cotton scorpion" to seal the gap to solve the gap that the ferrule cannot cover. There is no drainage line to ensure its watertight performance, and other performances are not to be said! The unit curtain wall is definitely leaking!
Sadly, for a long time, being a magic weapon for a large company to win the enemy, some curtain wall experts as a magic weapon to deal with the arc curtain wall, how many owners have fooled!
Five. Leakage at the junction between the curtain wall and the wall
1). How to deal with the connection between the curtain wall and the wall to avoid water leakage.
Firstly, the wall and the curtain wall are connected by a 1.5mm thick galvanized iron plate, and both of them are sealed with rubber. We call it a hermetic plate, which is used to facilitate shearing and bending to accommodate field changes. Make an aluminum plate to seal the outside. Inside is handled inside.
2), a waterproof can not prevent, two waterproof is safe, three waterproof should be considered.
There are three basic conditions that cause water seepage and water leakage in the curtain wall: there are pores; there is water; there is a pressure difference with water seepage cracks.
Eliminating one or more of these basic conditions is a way to prevent water leakage: one is to minimize the pores; the other is to block the rainwater so as not to wet the gap; the third is to reduce the wind pressure difference at the wetted gap.
1). When designing, first consider the design and construction of the curtain wall waterproofing device, using the equal pressure principle, and set the equal pressure chamber and the special pressure introducing hole on the aluminum profile of the curtain wall, so that the internal pressure of the equal pressure chamber is balanced with the external pressure through the special pressure introducing hole. Move the pressure difference to the side of the room that is not exposed to rain. Therefore, there is no difference in wind pressure at the water and there is no water in the part with pressure difference, which prevents the external water from using the pressure difference to penetrate into the curtain wall. This is an active waterproof measure. .
2). Opening a small water outlet hole on the aluminum profile of the curtain wall, collecting the water entering the curtain wall through the small gap and discharging it outside the curtain wall, and discharging a small amount in the isobaric cavity between the glass, the aluminum profile and the aluminum buckle. Water accumulation, this is one of the effective methods of water control.
3). When designing, it is also conceivable to set up collection pipes and drainage pipes on the glass curtain wall, collect the water that has penetrated into the cracks into the curtain wall, and smoothly discharge them through the drainage pipes to a designated drainage hole in the room. This is another Reliable water control measures.
4). Use high-quality structural silicone sealant, weather-resistant silicone sealant and wall edge glue, and strengthen inspection to prevent overdue use. The choice of high-quality float glass, the glass must be treated by the edge, the size error of the glass meets the standard requirements.
5). Pay attention to controlling the use environment of the sealant. It is strictly forbidden to carry out the construction of weather-resistant silicone sealant in the open air on rainy days. The construction workshop of structural glue requires clean and dust-free, and the indoor temperature should not be higher than 27 °C (the structural adhesives of different brands have different performances, and the indoor temperature requirements are slightly different), and the relative humidity should not be lower than 50%.
6). Before the silicone sealant, weather-resistant silicone sealant and wall edge glue are injected, the dust, oil stains, loose objects and other dirt on the aluminum frame, glass or gap should be cleaned first. Fill in the compact, smooth surface, strengthen the maintenance, prevent hand touch, water wash and so on.
7). According to the requirements of the specification, the rain curtain leakage performance inspection should be carried out in layers during the construction of the glass curtain wall in order to repair and control the quality of the curtain wall.
8). The quality inspection of the glass curtain wall is divided into two categories: concealed acceptance and engineering acceptance. Concealed acceptance is carried out after the installation of the aluminum profile frame. The main inspection is to ensure the firmness of the connection of the steel code, and to verify the installation of the gap between the curtain wall and the main structure, and the installation of the expansion joint. The acceptance of the project is carried out after the completion of the glass curtain wall project, which is the completion acceptance of the glass curtain wall and is the intermediate acceptance of the sub-project.
9). The opening window should be carefully checked to see if it has reached the degree of sealing. Whether the parts are of good material quality, reliable function, and whether the opening and closing are flexible.
10). When cleaning the curtain wall, use the building's own window cleaning machine. If it is cleaned by a professional cleaning company, there must be a detailed construction organization plan and no damage to the curtain wall.
11). Improve the completion acceptance data and hand it over to the relevant departments. The user should formulate the maintenance and repair plan and system of the curtain wall in time according to the instruction manual.
The above-mentioned curtain wall leakage prevention experience is through many trials and design improvements of our entire curtain wall people. Finally, through various aspects of recognition and meeting the requirements of various performance levels, it is our valuable successful experience in the prevention of water leakage in curtain wall engineering.
Contact: Ms. Sherry
Add: Donguan Industry Park, Jiyang District, Jinan City, Shandong Province, China