Why we use it
BCG considers it where assembly durability and installation quality are more important than chasing a single product claim.
Character
It is dense, friction-fit, and more resistant to moisture absorption than many common batt products.
What we look for
Correct product, thickness, fit, cavity conditions, continuity, and coordination with air sealing and vapor strategy.
Design considerations
Rockwool works best when the wall or roof assembly is designed as a system, not as a product substitution.
Installation considerations
Cuts should fit tightly without compression. Penetrations and transitions still require air sealing.
Common mistakes
Assuming moisture tolerance means moisture can be ignored, or using good insulation in a poorly sealed assembly.
Maintenance + aging
If a leak occurs, the assembly should be opened and assessed rather than assuming any insulation remains acceptable.
