Warranty, Certifications & Approvals

Download warranty and product certifications including Warnock-Hersey approvals.

Product Warranty

At Williams Brothers Corporation of America, we are committed to delivering superior craftsmanship and reliability. Our products are engineered to meet the highest industry standards, ensuring exceptional performance and longevity. As a testament to our unwavering commitment to quality, we offer the following comprehensive warranty:

Product Warranty

Certifications & Approvals

Abrasion Resistant Finish

  • Tested to ASTM D4060 Standards – Industry-recognized testing for abrasion resistance of coatings
  • 4,550 Abrasion Cycles Before Wear-Through – Demonstrates long-lasting durability under extreme conditions
  • Wear Index of 91.1 – Indicates excellent resistance to scratching, scuffing, and surface wear
  • High-Performance Finish – Maintains appearance and integrity in high-traffic environments
  • Ideal for Commercial & Industrial Applications – Built to withstand repeated impact and friction

Abrasion Resistance Test Report

Applies to all access doors except DW405, DWAL, FRU and FR-RDW models.

Fire Rating Approvals

Our Fire Rated Access Doors are designed to provide fire protected and secure service access to critical areas in walls and ceilings for a wide range of commercial, industrial, institutional and residential applications. Offering both UL®: and Warnock Hersey® approvals, our fire rated doors are an excellent choice for locations where a fire rated product is required by code.

WB FR 800, FRU 810 Ultra & FR 820 Access Door – Floor and Ceiling Assembly – These WB FR access doors are insulated and rated by Underwriters Laboratories for 1.5 hour “B” label in walls, and may be used in 2 hour fire rated wall assembly. Additionally, Warnock Hersey rated these WB FR access doors for 3 hours in ceilings.

WB FR-C 800 Series Ceiling Access Door – Warnock Hersey International approved for 1 hour fire rated ceiling
assembly up to (max 24” x 48”).

WB FR 850 Series Upward Swinging Access Door – Warnock Hersey International approved for ceiling, 3 hours.

Warnock-Hersey International Approvals

WB FR-C 800 Series Ceiling Access Door – This door has also been tested by an independent laboratory to achieve a 1- hour fire resistance rating accordance with ASTM E119-24 and CAN/ULC S101-14.

FR-C 800 Fire Rating Test Report

Salt Spray Test Certified Finish

Our access doors have passed independent ASTM B117-19 salt spray testing, demonstrating excellent resistance to corrosion—even under continuous exposure to a harsh 5% salt fog environment for 48 hours. Only minor red rust was observed on cut edges, with the primary surfaces maintaining their finish integrity.

  • Passed ASTM B117-19 48-hour salt spray test
  • Independently tested by Element Materials Technology
  • Excellent corrosion resistance under harsh conditions
  • Minimal red rust observed only on cut edges
  • Core finish remained intact and unaffected
  • Ideal for demanding, moisture-prone environments

Salt Spray Certification Test Report

Applies to all access doors except DW405, DWAL, FRU and FR-RDW models.

Sound Transmission Certifications

Our access panels are engineered to meet high-performance acoustical standards, effectively reducing noise transmission and enhancing overall sound control within buildings. These panels are tested in accordance with ASTM E90, ensuring reliable and consistent sound attenuation when installed properly. Incorporating sound-rated access panels contributes to improved occupant comfort, privacy, and acoustic performance, making them ideal for environments such as hotels, offices, healthcare facilities, schools, and other noise-sensitive areas.

  • STC: 62 or 63 (when installed properly) – Effectively minimizes airborne
    sound transmission, helping maintain quiet interior spaces.
  • OITC: 50 (when installed properly) – Provides superior protection
    against exterior noise penetration.

WB DWAL 412-HD Sound Transmission Test Report

WB DW 405 & DW 405-SQ Phantom Sound Transmission Test Report

WB EXT 1350 Sound Transmission Test Report

UV Rated Finish

Our painted access panels underwent rigorous accelerated UV exposure testing using both Xenon Arc and Fluorescent UV chambers. After 48 hours of accelerated UV testing—simulating long-term sun and weather exposure—our finish showed virtually no fading, discoloration, or degradation. This proves our doors are built to withstand harsh outdoor conditions while maintaining their appearance and integrity over time.

  • Passed ASTM G154-23 (Fluorescent UV) and ASTM G155-21 (Xenon Arc) standards
  • 48-hour accelerated UV exposure—equivalent to extended real-world sun damage
  • No visible change in finish, color, or gloss—pre- vs. post-exposure
  • Independently tested by Element Materials Technology
  • Designed for outdoor, high-UV, and sun-intensive environments

UV Rating Test Report

Applies to all access doors except DW405, DWAL, FRU and FR-RDW models.

Wind Load Certifications

Laboratory Tested and Certified in Accordance with ASTM E330/E330M-14(2021) to DP-52 for Winds Up to 144 mph (equivalent to category 4 hurricane).

WB EXT 1350 Wind Load Test Report