DW144 Ductwork — Compliance You Can Specify With Confidence
DW144 is the specification for sheet metal ductwork published by BESA (the Building Engineering Services Association). It defines how ductwork must be constructed — sheet gauges, joint types, stiffening, sealing and air-leakage classes — so that a duct system performs as the designer intended.
When a mechanical specification says "ductwork to DW144", it's the difference between a system that holds its pressure class and one that leaks conditioned air into ceiling voids for the life of the building. Every section we fabricate meets or exceeds the specification, without exception.
What DW144 actually covers
- Sheet gauges matched to duct dimensions
- Stiffening — beads, cross-breaks and stiffener frames
- Approved seam and joint constructions
- Sealant requirements for pressure-tight systems
- Pressure classes and air-leakage limits
How we build compliance in
Our fabrication settings encode the DW144 gauge and stiffening tables, so a 300mm duct and an 1800mm duct automatically come out with different sheet, different beading and the right joints. Seams are sealed in oil-based mastic as standard. When your commissioning engineer pressure-tests the system, it passes.
Specifying DW144 ductwork for your project
We work directly from your drawings, schedules and specification clauses, and our quotations state DW144 construction explicitly so your compliance trail is clean. Price standard parts online or send your specification.
Frequently asked questions
What is DW144?
DW144 is the UK industry specification for sheet metal ductwork, published by BESA. It defines construction standards — gauges, joints, stiffening, sealing and air-leakage classes — so ductwork performs as designed. It's the standard referenced by virtually every UK commercial mechanical specification.
Is all your ductwork DW144 compliant?
Yes. Every duct section and fitting we manufacture — rectangular and spiral — meets or exceeds DW144. It's our default build standard, not an optional extra.
What are DW144 pressure classes?
DW144 classifies systems as low, medium or high pressure, each with maximum operating pressures and permitted air-leakage rates. The class determines construction details like sealing and stiffening. Tell us the class on your specification and we fabricate accordingly.
Do you provide documentation for compliance records?
Our quotations and order confirmations state DW144 construction, giving you a clear paper trail for your QA and O&M records. If your project needs specific supporting documentation, tell us what the spec requires and we'll accommodate it.