How does the use of sealants on concrete bins impact their breathability?

The application of sealants to concrete bins is a common practice aimed at preventing water ingress and protecting the structure. However, this directly impacts the bin's natural breathability—its ability to allow moisture vapor to pass through the concrete walls. While sealants effectively block liquid water and reduce surface spalling, they can trap moisture vapor inside the bin. This trapped moisture, from stored commodities like grain or from temperature fluctuations, can lead to increased condensation. This condensation promotes mold growth, spoilage of stored goods, and potential corrosion of metal bin components. Therefore, the decision to seal requires a balance. For environments with high external moisture, a vapor-permeable or "breathable" sealant may be preferable. It repels liquid water while allowing internal moisture vapor to escape, mitigating condensation risks. Proper assessment of the primary threat—liquid water intrusion versus internal vapor buildup—is essential for selecting the right sealant to maintain optimal storage conditions and structural longevity.