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  • Writer's pictureAdam Sawyer

BS 476 Class 0 for Wood

Updated: Dec 16, 2023

Fire safety is a crucial factor in the building and construction industry. The materials used in construction must meet specific fire safety standards, one of which is the British Standard (BS) 476 Class 0, a rigorous fire rating system predominantly used in the UK. In this blog post, we will delve into what BS 476 Class 0 rating means, how it is tested, and how that enables wood to be certificated to BS 476 Class 0.

What is BS 476 Class 0?

BS 476 Class 0 is a classification given to materials, composites, or assemblies that have undergone the testing procedures specified in BS 476 Part 6 and Part 7. These tests measure both the material's contribution to the growth of fire and the rate and extent of its flame spread.

What is BS 476 Part 7?

BS 476 Part 7 defines the testing methods for evaluating the surface spread of flame in building materials and structures. It assesses how quickly and extensively flame spreads laterally along a vertically-positioned specimen. The results of this test provide valuable comparisons for the fire performance of various materials, composites, or assemblies, often used as the exposed surfaces of walls or ceilings

Achieving BS 476 Class 1

To attain the Class 1 rating, the material must demonstrate that the surface spread of flame is within the boundary of 165mm. Successfully achieving a Class 1 rating indicates that the material performs well under fire conditions, especially in its use as an exposed surface of walls or ceilings. It's important to note that achieving this rating is a prerequisite for pursuing the more demanding BS 476 Class 0 certification.

What is BS 476 Part 6?

BS 476 Part 6, outlines a method of testing fire propagation in flat materials, composites, or assemblies. The test results are expressed as a fire propagation index, offering a comparative measure of a material's contribution to the growth of a fire. This test is chiefly used to assess the performance of materials that are primarily used as internal wall and ceiling linings. By demonstrating a material's contribution to fire growth, it serves as a crucial indicator of the fire safety performance of these interior surface materials.

Achieving BS 476 Class 0

If the material successfully meets the Class 1 rating requirements, it then undergoes the BS 476 Part 6 Fire Propagation test. To qualify for a Class 0 rating, the material must have a fire propagation index (I) of not more than 12 and a sub-index (i1) of not more than 6.

A Class 0 rating, therefore, signifies a material that provides a high level of fire resistance and low contribution to fire growth.

How are flame retardants tested for BS476 Class 0?

Flame retardants undergo stringent testing to certify their compliance with the BS 476 Class 0 standards. These products are applied to various materials, which are then subjected to tests conducted by UKAS-accredited testing houses using established testing methods, including those discussed previously.

Following the manufacturer's instructions in the application of these flame retardants is critical in enhancing the fire resistance of materials, such as wood, to meet the required safety standards. This thorough testing process ensures that treated materials effectively limit the spread and intensity of fire, thus meeting the BS 476 Class 0 criteria.

In Summary

A Certificate of Compliance can indeed be issued for wood treated with flame retardants, provided these treatments have been rigorously tested by UKAS-accredited laboratories. This certification confirms that the treated wood meets the stringent requirements of the BS 476 Class 0 fire safety standard..

Recent Case Study: Plant Plan's Wooden Planters BS 476 Class 0 Treatment

In a recent collaboration, we had the privilege to serve Plant Plan, which specializes in expertly designing, installing, and maintaining planting and green walls for Offices, Hotels, and Restaurants.

We undertook a project for them where we treated wooden planters to meet the BS 476 Class 0 fire safety standard at their Leicester site. The execution was seamless, ensuring that the treatment and certification were completed within a day. The promptness allowed Plant Plan to prepare the planters on the same day, ensuring timely delivery to their client.

This real-world application underlines our commitment to excellence and punctuality, proving once again that when it comes to fireproofing, we stand second to none.

Our BS476 Class 0 Fire Retardant Spraying Service (case study)

Cirque Le Soir, the exclusive nightclub in Soho, was holding one of their incredible themed nights and requested a fire retardant with a BS 476 Class 0 rating to be applied to the MDF wood used in the construction of the scenery. We were able to provide the requested fire retardant spraying service, ensuring that the materials would be treated to the highest safety standards.

Reach Out for a BS476 Class 0 Certificate

If you need a BS476 Class 0 certificate for your wood projects, our team at Fireproofing is here to help. Here's how you can get in touch with us:

  1. Visit our website for more information:

  2. Call us directly at 07970 522475 to speak with one of our experienced team members.

Request a Certificate:

For a certificated service, please provide us with the necessary details about your wood project, such as the type of wood, dimensions, and fire safety requirements. Our experts will guide you through the process and ensure that your wood meets the required fire safety standards.

Before reaching out, consult with your fire officer or risk assessor to determine the specific standard they require for your project. To receive an accurate quote, be sure to calculate the treatment needed for both sides of the wood, if applicable.

Our team at Fireproofing is dedicated to providing exceptional customer service and ensuring the safety of your wood projects. Contact us today for professional guidance and assistance.


About the Author: Adam Sawyer

Adam is an industry expert with over 35 years of experience in textile care and fire retardant treatments. He is the founder of Fireproofing, a company specializing in fire retardant spraying and application services for curtains, fabrics, upholstery, wood, and more. With a strong commitment to customer satisfaction and safety, Adam has built lasting relationships with clients and established a reputation for excellence in the field. To learn more about Adam and Fireproofing, visit About Us & Our Expert.



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