Is Johns Manville insulation any good?

Yes, Johns Manville insulation is considered very good and is one of the top two fiberglass insulation brands in the United States alongside Owens Corning. It is a professional-grade product trusted by builders, contractors, and energy auditors. Owned by Berkshire Hathaway since 2001, Johns Manville manufactures its residential insulation in US plants in Kansas, Ohio, and Georgia with strict quality control and ASTM testing. Its fiberglass batts and blown-in products like Climate Pro and ComfortTherm are well regarded because they use a formaldehyde-free, plant-based binder that produces less dust and itching than older fiberglass, and they are GREENGUARD Gold certified for low chemical emissions. In field performance, Johns Manville products consistently achieve their labeled R-value when installed correctly without compression. Contractors often prefer Johns Manville over Owens Corning because it is typically 10 to 15 percent cheaper per square foot for the same R-value and because its Climate Pro blown-in fiberglass offers excellent coverage per bag. Its Spider spray-in system is considered one of the best wall insulation systems for new construction because it fills gaps completely and provides R15 in 2x4 walls and R23 in 2x6 walls. Its MinWool mineral wool line is excellent for fire resistance and soundproofing. The only minor complaints are that some batts are slightly less stiff than Owens Corning Pink, so they may need stapling, and retail availability varies by region. Overall, it is a high-quality, reliable, and cost-effective insulation choice.