Sealant aging and its correlation with facade reflectance

• Fatigue resistance of sealant joints is evaluated by experiments and FEM.
• Surface temperature of facades is calculated as a function of solar reflectance.
• A change of emissivity hardly changes surface temperature of the facade.
• Inner stress is calculated to evaluate fatigue damage for sealant joints.
• Facade solar reflectance should be made as high as possible.

A highly reflective facade may enhance the durability of sealant joints. This study investigates that reflective facades reduce thermal movement loading to sealant joints due to less fluctuations of surface temperature, and therefore lower fatigue damage of sealant joints. Cumulative fatigue damage was calculated to less than 1.6% in the first year. This damage considering only the first year is not that large, however, serious fatigue damage would ensue from the accumulated deterioration of sealants during a longer period, e.g. 10–25 years. It is therefore recommended that the facade solar reflectance should be made as high as possible.