Johns Manville's R-38 Unfaced Formaldehyde-Free Fiberglass Insulation is ideal for high-performance applications requiring superior insulation and sustainability. Its unfaced construction is perfect for enclosed cavities or spaces where vapor barriers are not needed or already exist. Each batt measures 12 in. x 19 in. x 48 in., and with eight batts per pack, it covers approximately 50.67 square feet. The insulation is lightweight, noncombustible, and naturally resistant to moisture and mildew, providing reliable long-term performance without settling over time. Whether you're insulating a new build or upgrading an existing structure, this solution balances energy efficiency with safe indoor air quality.