+44 (0) 1723 502 440 sales@firthsheetmetal.com

Fire Rated Ductwork

At Firth Sheet Metal Ltd, we’re a large and reliable manufacturer of custom sheet metals and steel solutions for various industries. Located in the United Kingdom, we’ve been providing services and products to private and public companies for almost 50 years, covering institutional, commercial and industrial accounts. Our company’s expertise ranges from custom duct design to safety requirements guards, ventilation design and installation. We offer reliable, professional and prompt services.

Our products include high-quality ductwork systems and sheet metal. We also focus on providing dependable services such as HVAC design and installation for both commercial and industrial use, fabrication, and installation throughout the United Kingdom. As a company, we’ve built our reputation on reliability and integrity – our customers know that they can count on us.

As a long-time provider of sheet metal fabrication, Firth Sheet Metal Ltd offers customers a cost-effective fabrication solution. We combine years of experience with the utilisation of advanced technology in order to produce quality products according to specification and on time.

We also combine our experience with flexibility to deal and work with different customers, ranging from large companies and corporations to independent parties looking for prototype parts. We take great pride in producing excellent and quality work and maintaining our track record of supplying dependable and effective metal fabrication services as a company.

Our customers choose us because of our commitment and accountability. Our reputation for providing quality services also assures our customers that they are safe in the hands of true professionals. Our excellent customer service has resulted in long term relationships with our customers throughout the United Kingdom. 

Contact us today about your project.

The flameshield is unique non-coated ductwork fabricated from galvanised sheet steel for state of the art equipment. The fabricated flame shield has been tested thoroughly under cellulosic fire conditions, and the product successfully passed the tests.

Our flame shield has been approved by building insurers, consultants, and building control officers. The fabrication process for these products has several benefits such as quick manufacture and installation, as well as being environmentally friendly and handling both internal and external heat.

The flame shield can be used in the following areas: car park extraction systems; ventilation systems; passive ventilation; smoke extraction systems and kitchen extraction systems.


We provide high-impact, fire-resistant Duraduct LT duct systems made from steel panels that offer excellent systems in the building and construction industry. We provide an economical fire-resistant solution combining wipe down and airflow characteristic of galvanised steel ductwork.

Our Customers

DW144 Ductwork

All our products are manufactured to the highest standards, in-line with DW144 specification for sheet metal ductwork. All sections are produced with an integral continual girth flange from one complete section of steel sheet. This delivers strength and quality far beyond the requirements of DW/144.


We are one of only a few UK companies licensed to manufacture Flameshield fire rated ductwork, compliant to BS 476 part 24. This is a non-coated, certified fire-rated ductwork system made from galvanised sheet metal on our dedicated machinery, which delivers performance and reliability expected of a leading brand.

Duraduct Lt®

We are one of only a few UK companies licensed to manufacture Promat DURADUCT LT,a Durasteel based fire rated product, compliant to BS 476 part 24 which provides up to 240 minutes fire resistance. This highly moisture resistant product retains integrity even when saturated, and does not absorb fluids such as cooking oil in kitchen extract systems.


At Firth Sheet Metal Ltd we can produce ductwork to customer drawings; or can provide a complete design service including, comprehensive site surveys, detailed 3D CAD drawings, and design calculations, all available for inspection if required. Our team have experience from a vast array of industries, and will work with you to provide the solutions you need.


Our 700m2 workshop is equipped some of the best tooling and machinery available, including Firmac CNC equipment, allowing our highly trained staff to provide top quality products. We pride ourselves in offering these high quality products quickly and efficiently at competitive prices.


As an accredited safe contractor we have a track record for excellence in health and safety. This is evident when working with our fully trained installation engineers. We are committed to safe and smooth installations from start to finish, and all staff have the necessary skill cards, IPAF training certificates.