Waterproofing Mini-Lesson | Materials Science: TPO or SBS for Roofing Systems?

Since the beginning of the 20th century, SBS (styrene-butadiene-styrene) bitumen-based waterproof membranes have been widely used in waterproofing projects. With the rapid development of the times, they have been continuously improved and evolved to take into account the importance of environmental protection. For a long time, they have remained popular due to their low cost.

As a representative of new synthetic polymer waterproof materials, TPO (thermoplastic polyolefin waterproof membrane) has developed rapidly in the European and American markets since its birth in the 1990s. Due to its advantages such as anti-aging, high tensile strength, large elongation, and ability to be applied to damp roofs, it has long occupied the number one position in the North American roofing market.

Today, Canlon will take the roofing scenario as an example to analyze the performance comparison of TPO membrane and SBS membrane, two common roofing waterproofing materials.

SBS roofing system

TPO roofing system

Weather resistance

TPO membrane: They have excellent UV resistance, effectively resisting aging caused by sunlight exposure, and their service life can typically reach more than 30 years.

SBS membrane: They have relatively weak weather resistance and are prone to aging and embrittlement when exposed to sunlight for a long time. Their service life is generally more than 10 years.

High and low temperature resistance

TPO membrane: They have good low-temperature bending properties and can maintain flexibility even below -40℃. They are not prone to flow and deformation in high-temperature environments (120℃).

SBS membrane: They have good low-temperature performance and can remain flexible at -25℃, but their high-temperature resistance is limited and they may flow at temperatures above 80℃.

Chemical corrosion resistance

TPO membrane: They have good resistance to chemicals such as acids, alkalis, and salts, and are suitable for chemical and industrial environments.

SBS membrane: They have poor resistance to chemical corrosion and are easily corroded by chemical substances, leading to a decline in performance.

Elongation and elasticity

TPO membrane: The elongation at break can reach over 800%, with good elasticity, and can adapt to roof deformation and settlement.

SBS membrane: The elongation rate is generally between 30% and 100%, and the elasticity is relatively weak.

Construction performance

TPO membrane: Installed using hot air welding or self-adhesive methods, they offer excellent joint sealing, high construction efficiency, and low requirements for substrate moisture content, allowing for application on damp surfaces. This saves time and costs associated with applying primer and pouring concrete.

SBS membrane: Typically require hot-melt installation, placing high demands on application temperature and substrate dryness, and joint treatment is relatively complex. Installation must be delayed during rainy weather. Due to inherent material limitations, a 5cm thick concrete protective layer may sometimes be required after installation.

Environmental protection

TPO membrane: Free from plasticizers, polycyclic aromatic hydrocarbons and other harmful substances, and can be recycled and reused during production and after use, with excellent environmental performance.

SBS membrane: Some products may contain harmful substances and may release harmful gases when burned, making them relatively environmentally unfriendly.

Material costs

TPO membrane: The material cost is relatively high, but because of their long service life, the total cost of production may be lower.

SBS membrane: The price is relatively low, but the maintenance costs may be high in roofs that have been used for a long time.

Final Summary

In summary, TPO roofing membranes offer significant advantages in weather resistance, chemical resistance, elongation, and environmental friendliness, making them suitable for roofing projects with high requirements for waterproofing and durability. SBS roofing membranes, on the other hand, remain a good choice for some ordinary roofs or temporary structures where performance requirements are not as stringent due to their lower cost. The specific choice should be made based on a comprehensive consideration of project needs, budget, and environmental conditions, or by consulting with professionals.