The UK standard for fabrication and installation of plastic ductwork is DW154, published by BESA, and recognised and used around the world. BESA is a trade association with interests across building services, and its members are audited against the specialist services they provide to ensure quality and compliance with standards. So Roperhurst as a fabricator and installer of plastic ductwork is audited by BESA, which we welcome because of the comfort it gives our customers.

But it begs the question “why aren’t all plastic ductwork fabricators members of BESA?” There are many potential reasons which we explore in more detail below.

Does their fabrication actually meet DW154? There are a number of requirements in DW154 which some fabricators struggle to meet:

  • Paragraph 10.2: [Where possible] Longitudinal seams should not be located at corners or in the underside of the duct. Plastic ductwork carries hazardous and dangerous substances – a weakness in a low corner/underside weld increases the risk of condensate leaking out. In order to meet this requirement, the fabricator needs to be able to bend the material at the corners, typically using a hot line bender. Not all fabricators have invested in this machinery, so their preference would be to use flat panels welded in the corners. This incorrect method is also cheaper – another reason why some fabricators choose it.
  • Paragraph 13.4.1: …[flanges] shall be mounted true and square to the duct surfaces and welded on both sides… Flanges mounted forward of the material are cheaper to prepare and weld, but they are poor practice as they create a potential sump for condensate. Given that this sump will be at a joint, the risk of leakage is greatly increased.

Does their company have sufficient internal standards to achieve membership? BESA membership requires high standards, and these in turn require investment:

  • Regularly inspected. BESA members are subject to regular third party inspection of technical competence and commercial capability.
  • Performance criteria: Members are required to meet industry recognised specifications and good practice guides
  • Health & Safety: Members must adhere to robust H&S policies, including compliance with CDM Regs
  • Mandatory insurance: BESA members must have in place adequate employers and public liability and professional indemnity insurance.

Do they really manufacture/fabricate themselves or is it actually all outsourced? There’s nothing like a customer visit to focus the mind. We encourage all prospective customers to know their supply chain – visit the fabricator, and ask them questions about BESA and DW154.

Is the fabricating company run by people with a trail of failure behind them? Unfortunately not every business has been around for quite as long as their sales team would have you believe. Roperhurst has been in continual existing for more than 40 years; some of our competitors have been through multiple versions of themselves, despite what their websites say. The commercial and financial standing of all BESA members is externally evaluated.

Roperhurst is proud of its involvement with BESA and its commitment to high standards of quality, including DW154. It’s a fact that both quality and compliance come at a cost, and we think it’s important to educate our customers about why they’re important, and what to look out for. You’re welcome to visit us at any time to discuss your ductwork requirements in more detail, just let us know and we’ll put the kettle on.

Contact us

If you are looking for a plastic solution, you’re in the right place. Our team will be happy to assist with your enquiry.

+44 (0) 1446 732555