Astm C920 Class 25 Vs Class 50 Guide

If you are sealing aluminum panels that are 10 feet long, the thermal expansion in summer can easily exceed the limits of a Class 25 sealant. Use Class 50.

Back in the site office, Marcus pulled out the dog-eared copy of ASTM C920 and laid out the facts. astm c920 class 25 vs class 50

Cost-effective, widely available, and sufficient for materials with low thermal expansion rates (like masonry to masonry). If you are sealing aluminum panels that are

for large glass panels, high-rise building facades, or any structure in a climate with extreme temperature swings where building materials are constantly growing and shrinking. high-rise building facades

Class 50 sealants are high-performance materials designed for dynamic, high-movement joints. They possess superior "elastic memory," meaning they return to their original shape after being stretched or compressed without permanent deformation.