Sealant is a substance that is commonly employed to seal the gaps between different building materials, such as concrete, glass, aluminum, and masonry walls. Joints are often incorporated into structures to mitigate the damage that can result from stresses. To this end, sealants are utilized to fill in the spaces between these materials and ensure a secure, airtight seal. By preventing the entry of air, moisture, and other unwanted substances, sealants can help to maintain the integrity of a structure over time. Overall, the use of sealants is an important aspect of construction and building maintenance.
Properties of Good Sealant
When it comes to selecting a sealant, there are a variety of options available, each with their own unique properties. However, there are some basic characteristics that a good sealant should possess. Firstly, it should have a strong bond with the building materials it is being applied to. This ensures that the sealant will effectively adhere to the surface and create a tight seal.
In addition to having a strong bond, a good sealant should also be soft and flexible. This enables it to move with the building materials as they expand and contract due to changes in temperature and humidity. A sealant that is too rigid may crack or break under these conditions, which can compromise the integrity of the seal.
Another important property of a good sealant is its ability to withstand weather changes. This means that it should not be affected by extreme temperatures, rain, snow, or other environmental factors. A sealant that is resistant to weather changes will provide a long-lasting seal that remains effective over time.
Finally, a good sealant should be strong enough to withstand stress and stress relief cycles. This means that it should be able to maintain its integrity even under pressure, and should not break or deteriorate over time. By possessing these properties, a good sealant will provide a reliable and durable seal that protects the building materials and ensures their longevity.
Types of Sealants Used for Joints in Buildings – Properties and Uses
In the construction industry, there are various types of sealants available, including silicone-based sealants, urethane-based sealants, acrylic-based sealants, and polysulphide-based sealants. Out of these, the most widely used sealant is the polysulphide-based sealant.
Polysulphide-based sealants are popular in the construction world because of their excellent bonding properties and durability. They are resistant to water, chemicals, and UV radiation, making them suitable for use in a wide range of applications. Additionally, polysulphide-based sealants are known for their flexibility and ability to maintain their seal even when exposed to extreme temperatures.
Overall, the polysulphide-based sealant is a reliable option for construction projects that require a strong and long-lasting seal. Its popularity in the construction industry is a testament to its effectiveness and the trust that builders and contractors have in its ability to meet their sealing needs.
Polysulphide based Sealant
Polysulphide sealants are popular due to their excellent sealing capabilities and are commonly used in various applications. These sealants are particularly useful for cold environments.
There are two types of polysulphide sealant systems available in the market. The first type is the two-part system, which requires mixing of two separate components before application. The second type is the one-part system, which is ready to use without any prior mixing required. Both types of polysulphide sealants offer effective sealing properties and can be chosen based on specific application requirements.
Two-part system
The sealant in question is a two-part system consisting of a base and an accelerator. In order to prepare the sealant, the two components must be thoroughly mixed together. Once mixed, a chemical reaction occurs, resulting in the formation of a thick paste. It is important to note that this paste should be used within 48 hours of mixing. After application of the sealant, it takes a full 8 days for it to fully cure.
There are two types of this particular Polysulphide sealant available on the market: gun grade and pour grade. Gun grade sealant is best used for inclined, vertical, and overhead joints. Pour grade sealant, on the other hand, is recommended for horizontal joints. It is important to use the appropriate type of sealant for the specific joint application to ensure maximum effectiveness.
One-part system
A one-part system is designed to contain premixed sealant that can be utilized directly without requiring any mixing. These types of sealants have a unique property that allows them to absorb moisture from the surrounding atmosphere, which triggers a reaction to occur. However, this also means that the sealant will require a significant amount of time to fully cure. In fact, it typically takes between 3 to 4 weeks for the sealant to cure completely. Therefore, it is important to factor in this curing time when using a one-part system with premixed sealant, to ensure that the sealant has sufficient time to fully cure and provide the desired level of performance.
Uses of Polysulphide based Sealants
Polysulphide based sealants are commonly utilized in various areas of construction due to their versatility and durability. One primary application of these sealants is in building structure joints. These joints may include basements, glazing frames, ceiling joints, floors, roofs, external walls, cladding, retaining walls, and more. By using polysulphide sealants in these areas, the joints are effectively sealed, preventing moisture and air infiltration which can cause damage and reduce the lifespan of the building.
Another significant application of polysulphide based sealants is in water retaining structures. These structures include dams, reservoirs, canal linings, culverts, and other water-related constructions. The sealants are used in the joints to ensure that water does not leak through the structure, which could cause significant damage to the surrounding environment and infrastructure.
Furthermore, polysulphide based sealants are also utilized in joints of bridges, roads, and aerodromes. These structures require a high degree of durability to withstand the constant traffic and exposure to the elements. Polysulphide sealants provide this durability, ensuring that the joints remain secure and prevent water and air infiltration that could cause damage.
In conclusion, polysulphide based sealants are essential in construction due to their versatility and durability. They are used in a wide range of areas, including building structures, water retaining structures, and transportation infrastructure, to ensure that joints are adequately sealed and protected from damage.
Equipment for Polysulphide based Sealants Application
When it comes to applying sealant, it’s important to use the proper equipment. This ensures that the sealant is applied correctly and evenly, which is crucial for its effectiveness. There are several pieces of equipment that are necessary for applying sealant.
Firstly, a filling device is necessary to load the sealant into the gun. The gun is used to apply the sealant onto the desired surface. A mixer is also necessary to ensure that the sealant is properly mixed and ready for application. A spatula can also be useful for smoothing out the sealant after it has been applied.
In addition to the above equipment, backup material is also needed to provide support and prevent the sealant from sagging. Bond breakers can also be useful to prevent the sealant from adhering to surfaces where it shouldn’t. Finally, masking tape can be used to protect areas that shouldn’t be touched by the sealant.
Overall, using the proper equipment for applying sealant is crucial for ensuring that it is effective and long-lasting. By following the necessary steps and using the right tools, sealant can be applied correctly and efficiently.
Filling Device
To apply sealant correctly and ensure its effectiveness, it is important to use the appropriate equipment. There are several pieces of equipment that are necessary for this task.
The first essential tool is a filling device that is used to load the sealant into the gun. The gun is the primary tool for applying the sealant onto the surface. Another necessary piece of equipment is a mixer, which ensures that the sealant is thoroughly mixed and ready for application. A spatula can also be useful in smoothing out the sealant after it has been applied.
To provide support and prevent the sealant from sagging, backup material is required. Bond breakers can also be helpful in preventing the sealant from adhering to surfaces where it shouldn’t. Finally, masking tape can be applied to protect areas that should not come into contact with the sealant.
In conclusion, using the appropriate equipment is crucial for effectively and efficiently applying sealant. By following the necessary steps and using the correct tools, sealant can be applied evenly and properly, leading to its long-lasting effectiveness.
Gun
A gun is a tool that is used to dispense sealant through PVC cartridges and nozzles. This device makes it easy to apply the sealant to joints in any position, allowing for greater flexibility and precision in the application process. With the use of a gun, the sealant can be placed precisely where it is needed, ensuring a tight and secure seal. The nozzles on the gun provide a controlled flow of sealant, making it easy to adjust the amount of sealant being dispensed based on the specific needs of the project. Overall, the gun is a highly effective tool for anyone who needs to apply sealant to joints, providing a simple and efficient way to achieve a perfect seal every time.
Mixer
When using a two-part sealant system, it is typically necessary to use a mixer. This is because both the base and accelerator components must be mixed thoroughly in order to achieve the desired results. Without proper mixing, the sealant may not cure properly or could have uneven properties that could compromise its effectiveness.
To ensure that the two components are mixed effectively, it is important to use a suitable mixer. The mixer should be able to blend the components together evenly and consistently, ensuring that no areas are missed. This will ensure that the sealant will perform as intended and provide the desired level of protection.
Overall, when working with a two-part sealant system, it is essential to use a mixer to ensure that the base and accelerator are mixed effectively. By doing so, you can ensure that the sealant will perform as intended and provide the level of protection that is required.
Spatula
The spatula can be utilized as a substitute for a gun in certain circumstances, but it is only suitable for small-scale tasks. When it comes to sealant application, there are additional accessories that can be used to improve its effectiveness. These accessories can enhance the overall application process and result in a more precise and efficient sealant application.
Backup material
The depth of the sealant in a joint is controlled by the back-up material.
Bond breakers
Bond breakers are materials that come in the form of tapes made of PVC, metal, or paper. These tapes are used to prevent three-face adhesion. By using bond breakers, adhesion between three surfaces can be avoided. This is because bond breakers create a barrier between surfaces that inhibits adhesion. Bond breakers are particularly useful in situations where a surface needs to be painted or coated without any overlap onto adjacent surfaces. In such cases, bond breakers can be applied to the edges of the surface to be painted to ensure that no paint or coating adheres to adjacent surfaces. Overall, bond breakers play an important role in preventing unwanted adhesion in various applications.
Masking tape
When applying sealant to joints, there is a risk that the sides of the joint may become damaged due to the spreading of the sealant. In order to prevent this from happening, masking tape is typically provided on both sides of the joint. However, skilled professionals may be able to apply the sealant without using the tape. This requires a certain level of expertise, as the person must be able to apply the sealant carefully and precisely without causing damage to the surrounding area.
Working Conditions of Polysulphide based Sealants
There are several factors to consider when selecting the appropriate sealant for a particular application or service. One of these factors is temperature. Depending on the environment in which the sealant will be used, it may need to withstand high or low temperatures. Therefore, it is important to choose a sealant that is able to maintain its integrity and effectiveness in the given temperature range.
Another factor to consider is the size of the joint that the sealant will be applied to. This is important because the sealant must be able to effectively fill the joint and create a durable, long-lasting seal. Choosing a sealant with the appropriate viscosity and flow characteristics can help ensure that it is able to properly fill the joint and adhere to the surfaces it is applied to.
The storage of sealant is also an important consideration. Proper storage can help ensure that the sealant remains effective and does not deteriorate or lose its properties over time. This is particularly important for sealants that have a limited shelf life or are sensitive to certain environmental factors.
Water resistance is another important factor to consider when selecting a sealant. Depending on the application, the sealant may need to be able to withstand exposure to water or other liquids. Choosing a sealant with strong water resistance can help ensure that it remains effective and durable in these environments.
Chemical resistance is also a key consideration. Depending on the application, the sealant may be exposed to a variety of chemicals or other substances that can degrade its performance or cause it to fail. Choosing a sealant that is specifically formulated to resist these substances can help ensure that it remains effective and long-lasting.
Other factors to consider include setting time and cure time, movement (i.e. how much the joint is likely to expand or contract over time), and durability. Taking these factors into account when selecting a sealant can help ensure that it is able to effectively and reliably perform its intended function over the long term.
Temperature (application and service)
When applying sealant, it is important to ensure that the temperature falls within a specific range for optimal results. The recommended temperature range for applying sealant is between 5 degrees Celsius and 50 degrees Celsius. This means that the sealant should not be applied in temperatures below 5 degrees Celsius or above 50 degrees Celsius.
However, once the sealant has been applied, it can effectively work and serve its purpose in a much wider temperature range. The sealant is designed to function effectively within the temperature range of -40 degrees Celsius to +80 degrees Celsius. This means that the sealant can withstand extreme temperatures as low as -40 degrees Celsius and as high as +80 degrees Celsius, without compromising its effectiveness.
Therefore, it is important to ensure that the sealant is applied within the recommended temperature range to ensure optimal results, and once applied, it can withstand a wide range of temperatures and continue to effectively serve its purpose.
Size of joint
When applying sealant to joints, it is important to ensure that the width of the joint falls within a specific range of 5 mm to 50 mm. This is a crucial factor to consider as it can affect the durability and effectiveness of the sealant. It is therefore essential to measure and verify the joint width before applying the sealant.
Another important consideration when applying sealant is the depth of the sealant applied within the joint. The depth of the sealant will vary depending on the type of structure that the joint is located in. For metal and glass structures, the depth of the sealant applied should be 5 mm. However, for concrete and brick joints, the depth of the sealant should be 10 mm.
By adhering to these guidelines for joint width and sealant depth, the sealant application will be effective and long-lasting. It is important to carefully follow these guidelines to ensure the sealant is applied correctly, and the joint is well protected. Any deviation from these guidelines could lead to inadequate protection for the joint and possible damage to the structure over time.
Storage of sealant
According to the information provided, it is possible to store the mixed paste of a two-part system sealant for a period of 12 months. This can be achieved by ensuring that the sealant is kept in a dry and cool place. Additionally, it is important to store the sealant in a closed container to prevent any external factors from affecting its quality. By adhering to these storage guidelines, the sealant can be kept in a suitable condition for an extended period of time, without the risk of it deteriorating or becoming unusable.
Water resistance
The sealant, once it has undergone full curing, will become resistant to water and impermeable. In other words, it will no longer allow water to pass through it and will provide a barrier to prevent the penetration of water. This quality makes it an effective choice for sealing areas where water intrusion may be a concern, such as in bathrooms or around windows and doors. The curing process is essential in achieving this level of water resistance and impermeability, as it allows the sealant to fully harden and form a durable barrier. Once cured, the sealant will maintain its water-resistant properties for an extended period, providing long-lasting protection against water damage.
Chemical resistance
Sealants possess a high degree of chemical resistance, making them highly effective in withstanding a variety of substances such as oils, petrol, white spirit, fuels, and more. This property allows them to maintain their integrity and perform their intended function even in the presence of harsh chemicals. The ability of sealants to resist chemical degradation makes them a popular choice for use in various industries, including automotive, construction, and manufacturing. The reliable performance of sealants in the face of exposure to chemicals makes them a valuable asset for protecting surfaces and ensuring long-lasting durability.
Setting time and curing time
The setting time and curing time will depends mainly on the temperature of that particular location. These times for different temperatures is given below.
| Temperature (oC) | 5 | 15 | 25 | 35 |
| Setting time (hours) | 72 | 36 | 18 | 8 |
| Curing time | 8 weeks | 4 weeks | 2 weeks | 8 days |
Movement
When it comes to applying sealant, it is important to take into account the potential for movement after application. Specifically, the movement of sealant can vary depending on the type of joint being used. For butt joints, it is estimated that the sealant may move up to 25% after application. This means that there may be some degree of shifting or displacement within the joint over time. On the other hand, for lap joints, the estimated movement of sealant after application is higher, at around 50%. This suggests that lap joints may experience more significant shifting or movement compared to butt joints. Overall, understanding the potential movement of sealant can help ensure that it is applied effectively and able to withstand the stresses and strains that may occur over time.
Durability
Sealants used in traffic surfaces such as roads and bridges can have varying lifespans. Some sealants can last up to 10 years, while others may last up to 25 years. Additionally, different types of joints in concrete construction require different sealing materials. For water retaining concrete structures, specific types of sealants may be necessary. In building construction, various types of joints also require sealing. Additionally, cracks in concrete may need to be routed and sealed with specific materials.