Utbe 8 [repack] May 2026

“UTBE 8 means the building survives 8 hours of fire.” Fact: It means the thermal barrier survives, protecting the structure. Contents may still burn.

UTBE 8 is an order of magnitude more demanding than a standard 1-hour wall. Its 8-hour duration addresses smoldering fires that may go undetected for long periods in attics. Materials That Achieve UTBE 8 Not every material can withstand 8 hours of heat. Below are approved UTBE 8 materials: utbe 8

| Material | Thickness Required | Notes | |----------|--------------------|-------| | Type X Gypsum Board | 5/8″ (two layers) | Most common, lowest cost | | Cement Board (e.g., HardieBacker) | 1/2″ | Moisture-resistant but heavier | | Intumescent Coating (e.g., DC315) | 20–30 mils (dry) | Spray-applied over foam | | Mineral Wool Board | 2″ | Excellent for curved surfaces | | Perlite Board | 1″ | High temperature, brittle | “UTBE 8 means the building survives 8 hours of fire