A mitigation product MIGHT help to limit the effects of high RH in concrete slabs BUT there are a number of important factors that will determine the ultimate outcome:
- The cause of the high RH levels
If additional moisture is being drawn into the concrete slab from any external source (groundwater, leaking plumbing, etc.), the internal RH levels will continue to rise even after a surface encapsulant is applied. A rising RH level may eventually exceed the moisture tolerance of the product and still cause moisture-related problems. - The mitigation product’s specific moisture tolerance
If the product’s moisture tolerance ratings are insufficient for the actual slab moisture content, then the high RH of the slab will likely cause encapsulant failure, along with the failure of all the flooring or finish products applied over it. - Ambient conditions around the slab
If the ambient conditions around the slab (air humidity, temperatures) are prone to significant changes or seasonal shifts, the high initial RH levels of the slab may be the result of poor drying conditions. Best practices would suggest ensuring drying conditions are optimized before applying any sealant or product to the concrete slab. If RH testing continues to show high RH levels, be sure that any products are chosen with appropriately high moisture tolerances, and always consult these manufacturers directly to discuss your specific situation. For a list of manufacturers that provide RH specifications for their products, visit www.rhspec.com.