This is 1 hour fire rated exterior wall which is similar to UL 365 with STC 35 min. This wall type has 1 hour rating based on 1 layer of gyp board and over each side of studs at 16″ O.C. per IBC section 721.6 Add to wish list $5.00 – Purchase Checkout Added to cart You must log in to submit a review. Username or Email Address Password Remember Me Buying Options Add to wish list $5.00 – Purchase Checkout Added to cart