Formulate elastomeric roof coatings for TPO membrane restoration
Roof coatings based on Encor® Flex 192 latex help extend the useful life of weathered TPO roof membranes.
As the installed base of thermoplastic polyolefin (TPO) roof membranes has started to age and show wear, elastomeric roof coatings have emerged as an excellent option to extend the useful life of the roof. By extending the life through maintenance with a roof coating, building owners can delay total roof replacement and lower their overall life cycle roof cost.
Excellent performance properties
Encor® Flex 192 is a modified acrylic latex that provides excellent performance properties in elastomeric roof coatings. Coatings based on Encor® Flex 192 display:
- Excellent adhesion to weathered TPO without solvent primers, helping to lower labor and material costs for roof maintenance.
- Enhanced dirt pickup resistance, helping to maintain solar reflectance and the energy savings of cool roof technology.
Adhesion to TPO membranes
The nature of polyolefin chemistry results in a membrane with low surface energy, making it difficult for a coating to adhere to the surface. Properly formulated coatings based on Encor® Flex 192 display excellent adhesion, especially to aged TPO membrane.
Figure 1 illustrates adhesion of Encor® Flex192 on new and aged TPO versus a competitive acrylic. As mentioned above, new TPO membranes have few active surface sites for bonding and adhesion of waterborne coatings. Although an aged surface is also difficult to adhere to, it is recommended for sufficient adhesion of a coating based on Encor® Flex 192. UV light breaks down the TPO surface and enhances coating adhesion.
Dirt pickup resistance
Coatings based on Encor® Flex 192 latex exhibit excellent dirt pickup resistance, helping to retain solar reflectance properties while protecting the roofing membrane underneath. The following figure shows the dirt pickup resistance of coatings based on Encor® Flex 192 and a competitive acrylic applied to an aluminum panel, allowed to dry for 7 days and exposed to UV light for 100 hours. A dirt slurry containing iron oxide and coal ash was applied to the coatings and allowed to dry for 24 hours before removal via wet sponge and 30 cycles on a scrub machine. The whiteness was recorded as "y" value initially and after dirt removal. Figure 2 shows the change in whiteness of coatings based on Encor® Flex 192 and a competitive latex, after dirt removal. The coating based on Encor® Flex 192 exhibits superior dirt pickup resistance.