The World's Largest Access Door Store™
Download warranty and product certifications including Warnock-Hersey approvals.
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:
The following models of access doors have been independently tested to ASTM D4060 – the industry-recognized testing for abrasion resistance of coatings. They demonstrated long-lasting durability under extreme conditions withstanding 4,550 abrasion cycles before the coating wore through. Our doors are designed to maintain their appearance in high-traffic environments making them ideal for demanding commercial and industrial applications.
Abrasion Resistance Test Report (PDF)
Applies to Basic 300, UAD 200, GP 100, GP-VIS 100, GP 101, GP 102, GP-LV 103, RP 110, SMP 120, FR 800, FR-C 800, DW 400, RDW 410, RDW 410-2, PL 500, EXT-PL 1450, EXT 1300, EXT 1350, EXT 1400, AL 1500 and AL 1600 models.
WB RH and RH-AL Series Roof Hatches are independently tested to ASTM standards for air leakage, water penetration, and structural performance. They provide a reliable access point to the roof — rugged and weather-tight.
Air, Water & Structural Performance Test Report (PDF)
The following models of access doors are Build America, Buy America Act (BABA) compliant. Manufactured with domestic steel and assembled in our Virginia facility, these doors fully meet BABA requirements by supporting U.S. manufacturing, job creation and infrastructure investment. Architects, contractors and builders who specify these doors can do so with confidence, knowing they are selecting a product that not only delivers long lasting durability and versatility, but also directly supports American workers and communities.
WB Basic 300 BABA Compliance Letter (PDF)
WB UAD 200 BABA Compliance Letter (PDF)
WB GP 100 BABA Compliance Letter (PDF)
WB GP-SS 100 BABA Compliance Letter (PDF)
WB GP 101 BABA Compliance Letter (PDF)
WB GP-LV 103 BABA Compliance Letter (PDF)
WB RP 110 BABA Compliance Letter (PDF)
WB SMP 120 BABA Compliance Letter (PDF)
WB DW 400 BABA Compliance Letter (PDF)
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 Doors – 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 Ceiling Access Door – Warnock Hersey International approved for 1 hour fire rated ceiling
assembly up to a maximum size of 24″ x 48″.
WB FR 850 Upward Swinging Access Door – Warnock Hersey International approved for ceiling, 3 hours.
Warnock-Hersey International Approvals (PDF)
WB FR-C 800 Ceiling Access Door – This door has also been tested by an independent laboratory to achieve a 1 hour fire resistance rating in accordance with ASTM E119-24 and CAN/ULC S101-14 up to a maximum size of 36″ x 36″.
WB FR-C 800 Fire Rating Test Report (PDF)
WB DW 405 & DW 405-SQ Phantom Drywall Access Doors – This door has also been tested by an independent laboratory to achieve a 1 hour fire resistance rating in accordance with ASTM E119-24 and CAN/ULC S101-14 up to a maximum size of 22″ x 30″.
WB DW 405 & DW 405-SQ Phantom Fire Rating Test Report (PDF)
Williams Brothers products combine durability, performance, and sustainability. Our access doors and panels are proudly manufactured in Virginia with domestic steel that offers verified LEED® contribution through its high recycled steel content. In addition, they are compliant with REACH international environmental standards.
LEED® & REACH Compliance Documentation (PDF)
WB RH and RH-AL Series Roof Hatches are independently tested to Miami-Dade hurricane standards for wind, water, structural, impact, and forced entry — making them ideal for hurricane-prone and high-security facilities.
Hurricane Air, Water, Structural, Impact & Forced Entry Test Report (PDF)
The following models of access doors have been independently tested for RF shielding effectiveness by Element Materials Technology in accordance with ASTM D4935 (IEEE-299 methodology). Testing demonstrated shielding effectiveness across 80 MHz to 18 GHz, with measured attenuation of approximately 50 to 80 dB depending on the model.
WB Basic 300, GP 100, GP-101, GP-102 & 412-HD Access Doors – Shielding effectiveness up to approximately 75 dB..
WB DW 405 & 405-SQ Phantom Drywall Access Doors – Shielding effectiveness up to approximately 50 dB.
WB DC-SS 900 Data Center Access Door – Shielding effectiveness up to 70–80 dB depending on frequency.
Radio Frequency (RF) Shielding Effectiveness Test Report (PDF)
The following models of 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.
Salt Spray Certification Test Report (PDF)
Applies to Basic 300, UAD 200, GP 100, GP-VIS 100, GP 101, GP 102, GP-LV 103, RP 110, SMP 120, FR 800, FR-C 800, DW 400, RDW 410, RDW 410-2, PL 500, EXT-PL 1450, EXT 1300, EXT 1350, EXT 1400, AL 1500 and AL 1600 models.
The following models of access panels are engineered to meet high-performance acoustical standards, effectively reducing noise transmission and enhancing overall sound control within buildings. These panels have been independently 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.
WB DWAL 412-HD Sound Transmission Test Report
WB DW 405 & DW 405-SQ Phantom Sound Transmission Test Report (PDF)
WB EXT 1350 Sound Transmission Test Report (PDF)
The following models of 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.
Applies to Basic 300, UAD 200, GP 100, GP-VIS 100, GP 101, GP 102, GP-LV 103, RP 110, SMP 120, FR 800, FR-C 800, DW 400, RDW 410, RDW 410-2, PL 500, EXT-PL 1450, EXT 1300, EXT 1350, EXT 1400, AL 1500 and AL 1600 models.
Ou EXT 1350 exterior access door has been independently 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).