If the silicone sealant has quality problems, it will lead to water leakage, air leakage and other problems, which will seriously affect the air tightness and water tightness of doors and windows.
Cracks and water leakage caused by failure of door and window sealant
So how do we choose the right sealant for doors and windows?
1. Correctly select products that meet the standards
During the selection of sealant, attention should be paid not only to the standard it meets, but also to its corresponding displacement level. Displacement capacity is the most critical index to measure the elasticity of sealant. The higher the displacement capacity, the better the elasticity of silicone sealant. The processing and installation of doors and windows should choose products with displacement capacity not less than 12.5 to ensure the long-term air tightness and water tightness of doors and windows.
During the installation and use of doors and windows, the bonding effect between ordinary sealant and cement concrete is usually worse than that with aluminum profiles or glass of doors and windows. Therefore, it is more appropriate to choose products conforming to JC/T 881 as the sealant for the installation of doors and windows.
Products with high displacement level have stronger ability to withstand joint displacement changes. It is recommended to choose products with high displacement level as far as possible.
2. Choose silicone sealant products correctly according to the purpose
Concealed frame windows and concealed frame opening fans need structural sealant to play the role of structural bonding. Silicone structural sealant must be used, and its bonding width and thickness should meet the design requirements.
During the installation of doors and windows, the sealant for stone joints or joints with stone on one side shall be the special sealant for stone that meets the standard of GB/T 23261.
Fireproof sealant is more suitable for fireproof doors and windows or external doors and windows of buildings that require fire integrity.
In the application places with special requirements for mold prevention, such as kitchens, sanitary baths and dark and wet parts, the sealing of door and window joints should use mold proof sealant.
3. Do not choose silicone sealant filled with oil!
At present, the market is full of a large number of oil filled door and window sealants, which are filled with a large amount of mineral oil and have poor aging resistance, which will lead to many quality problems.
Silicone sealant mixed with mineral oil is called "oil filled silicone sealant" in the industry. Mineral oil belongs to saturated alkane petroleum distillation. Because its molecular structure is very different from that of silicone, its compatibility with silicone sealant system is poor, and it will migrate and penetrate out of silicone sealant after a period of time. Therefore, the "oil filled sealant" has good elasticity at first, but after using for a period of time, the filled mineral oil migrates and penetrates from the sealant, and the sealant will shrink, harden, crack, and even have the problem of non bonding.
Most low-cost silicone sealants on the market are filled with mineral oil, and the content of silicone basic polymer is far less than 50%, and some are even less than 20%.
If the sealant of the gas filling window contacts with the insulating glass, the filled mineral oil will migrate and penetrate into the insulating glass, resulting in the dissolution of a sealing butyl rubber of the insulating glass and oil flow.
Choose high-quality sealant products. Although the price of sealant purchased at the initial stage is slightly higher, its performance can be preserved for a long time without quality problems. Choose low-cost low-quality "oil filled sealant", although the price is cheap, the initial investment cost is slightly lower; However, after problems occur, the later maintenance costs, product costs, labor costs, brand losses, etc. during rework may be several times or even dozens of times the price of the sealant itself; Not only did it not save money, but it added a lot of trouble to users.
Post time: Jul-07-2022