How long do sealants last

# How long can sealant in the construction industry last? 

In modern buildings, those seemingly insignificant gaps are where the sealant is quietly safeguarding the durability and safety of the structure. Its lifespan is much longer than what most people imagine. 

The durability of sealant depends on several factors, including product quality, installation process, compliance with technical standards, and environmental conditions, etc. High-quality sealant, when properly applied and maintained, can have a service life of up to 25 years or even more than 50 years. 

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 01 High-Quality Products, Foundation of Longevity 

The lifespan of sealant primarily depends on its **material quality**. Research has shown that high-quality silicone sealant can maintain excellent performance for about 25 years when used in actual projects. 

Sulfurized sealant performs even better. It not only possesses the properties of synthetic rubber, but also has certain characteristics of plastics, such as **resistance to water immersion, resistance to heat and humidity, resistance to oil, and resistance to solvents**. 

This type of high-quality sealant has excellent adhesion to both metal and non-metal materials, and also exhibits good low-temperature flexural performance. Its operating temperature range can reach **-40 to 90 degrees Celsius**. 

In practical application cases, polysulfide sealant has been in use in the United States for over 50 years and has become a durable representative among building sealing materials. 

 02 Installation Process, Determining Success or Failure 

Even the best products require proper installation to fully realize their long-term performance. The application of sealant is a task that demands **meticulous attention to detail**. 

Before construction, it is necessary to perform **substrate treatment**: Use alcohol, acetone or specialized cleaning agents to remove impurities such as oil stains, dust, moisture, and release agents from the surface of the substrate, ensuring that the base layer is dry, clean and flat. 

The construction environment also has strict requirements: the temperature should be between **5℃ - 35℃**, the humidity should be less than **75% RH**, and the moisture content of the substrate should be controlled below **8%** (for concrete). 

The gluing operation requires professional skills: The glue gun and the substrate should maintain a 45-degree angle, the nozzle of the gun should be close to the bottom of the joint, move the gun at a constant speed and squeeze the gun to ensure that the glue fully fills the gap and avoids air holes or bubbles. 

For seams wider than 10mm, it is recommended to first fill them with foam rods (with a diameter 1.3 times that of the seam width). This will reduce the amount of adhesive used and enhance the support of the backing. 

 03 Standards and Specifications, Quality Assurance 

Our country has established a complete set of sealant standards, providing technical support for the durability of sealants. The main standards include: 

GB/T 14683-2017 "Silicone and Modified Silicone Building Sealants", GB 16776-2005 "Building Silicone Structural Sealants for Construction", GB/T 23261-2009 "Building Sealants for Stone Materials". 

These standards set clear requirements for the performance indicators of sealants, including **tensile bonding strength, elongation at break, thermal aging performance, low-temperature flexibility, and resistance to contamination**, etc. 

Supervisory inspections are an important means to ensure the implementation of standards. In 2024, the provincial-level supervisory inspection of the quality of building sealants in Shandong Province conducted a total of 23 batches of products from the production sector, and **no不合格 items were found**. 

 04 Selection and Usage Guide 

When faced with a variety of sealant products on the market, choosing the right type is of utmost importance. Silicone sealant is suitable for decorative sealing of **facade, doors and windows**, as well as processing of insulating glass. 

Polyurethane sealant is suitable for sealing the joints of concrete and masonry structures. Polysulfide sealant is an ideal waterproof sealing material for expansion joints of liquid storage structures. 

When purchasing, it is necessary to check the environmental protection performance of the product and ensure that it complies with national environmental protection standards such as GB 33372-2020 and GB 18583-2008. 

After construction, appropriate curing and hardening must be carried out. The surface drying time of silicone sealant is approximately 30 minutes to 2 hours, but complete curing usually takes 24 to 48 hours. 

The surface drying time of the polysulfide sealant is 24 hours, but it takes 7 days for it to reach 80% of its curing degree. **The water-tightness test should generally be conducted 7 days after the construction is completed.** 

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Actual cases have proved that high-quality silicone sealant can maintain excellent performance even after being used in projects for 25 years. And polysulfide sealant performs even better, with its actual usage duration in the United States reaching **more than 50 years**. 

The long-term durability of the sealant is also attributed to the strict technical standards and comprehensive quality supervision system in our country. 

These standards have imposed strict regulations on various aspects of sealant, including its resistance to chemicals, elongation at break, viscosity, fire resistance, and weather resistance. They provide a strong guarantee for the quality and safety of buildings.