Polyurethane sealants are organic products, composed of urethane polymers. They are commonly used in industry and construction for sealing concrete, automotive, masonry and marine applications. Polyurethane sealants are strong and durable with an excellent abrasion and impact resistance.
Below we have highlighted some of the pros and cons of using polyurethane sealants
Pros |
Cons |
Paintable |
Poor weather resistance |
Excellent abrasion resistance |
Short shelf life |
UV resistant |
Not as durable as silicone based sealants |
High strength |
Not suitable for medical applications due to toxicity concerns |
Chemical and oil resistance |
Can degrade at high temperatures |
Bondable with a variety of materials |
Can release VOCs during the curing process |
Advantages of Silicone Sealant for Concrete
Silicone sealants have become an essential material in the construction industry, from sealing gaps and joints to ensuring structural integrity and weatherproofing, silicone sealants have many advantages in construction applications.
Silicone sealants provide an effective seal against water infiltration, which makes them suitable for sealing exterior surfaces which are exposed to rain and humidity.
Silicone sealants offer a high degree of flexibility and movement. Construction materials frequently expand and contract due to temperature fluctuations and structural shifts, silicone sealants are able to withstand this movement without compromising their adhesion and sealing capabilities. This flexibility helps to prevent cracks and damage to sealed surfaces.
Unlike other sealant formulas, silicone based sealants have a low thermal expansion rate, meaning that they can withstand high temperatures without becoming misshapen or losing structural integrity. This means they are ideal for applications where temperature fluctuations are common.
Silicone sealants are typically long-wearing and durable, meaning that they maintain their sealing properties over an extended period of time. This results in lower maintenance costs and less time needed for repairs and replacements.
Silicone sealants are available in a wide variety of colours, allowing them to enhance the aesthetic finish of the project and blend seamlessly with the surrounding areas. This makes silicone sealants ideal for both functional and decorative applications.
Choosing the Right Sealant: Factors to Consider
Choosing the right sealant for your construction project is a crucial element to its success and longevity. With a vast range of sealants available to purchase, it is important to consider some key factors that may help you to decide which is the perfect sealant formulation for your project's needs.
Prior to choosing the right sealant you need to identify the requirements of your project, understanding what it is you need to seal, where it is and how it will be used once sealed.
It is important to take into consideration the joint movement and expansion that may take place and how that will affect the functionality of your sealant. In applications prone to movement such as buildings and automotive
If the sealant will be visible, you should consider its decorative capabilities such as if it can be painted over. Polyurethane sealants are paintable and silicone sealants are not however, they do come in a variety of colours.
You should consider the environmental conditions that the sealant will be exposed to if used externally. The performance and longevity of the sealant can be affected by factors such as temperature fluctuation, UV exposure, humidity and moisture levels.
Application and Curing Time for Polyurethane Sealant
The application process for polyurethane sealants is dependent on the specific type of sealant being used. One-component sealants begin curing once exposed to the air whereas two-component sealants require the mixing of two components before application.
The curing period for polyurethane sealants sees the transition of the product from a liquid to a solid state. The curing time is affected by factors such as sealant formulation, temperature, humidity and ventilation.
Longevity and Weather Resistance of Silicone Sealant
Silicone sealants have excellent weather resistant properties. They have a high degree of flexibility which means they do not crack or peel easily when exposed to fluctuations in temperature. As silicone sealants are also moisture resistant, they are able to hold up well in rainfall and against any other precipitation, meaning they are an ideal choice for external applications that may be exposed to extreme weather conditions.
Conclusion: Selecting the Ideal Sealant for Concrete
When attempting to select the ideal sealant for sealing concrete it is important to consider all of the factors discussed above, and look at the pros and cons between both silicone and polyurethane formulas. The ideal sealant for your project will be dependent on your requirements and the environmental conditions.