Cavity Closer

The Duraflex Diamond Suite - Making The Difference

Cavity Closer

Cavity Closer

A comprehensive range of Cavity Closers and an overhead vent that provides an accurate template during construction, insulates the cavity and ensures efficient window installation.

A complete New Build System to suit all construction methods, the Duraframe is fully approved by BBA and covers cavity widths from 70mm to 150mm

Available for all cavity width dimensions with a unique extension system ensuring regulation compliance. Closers can be constructed in P and T Shapes, bespoke sizes/shapes and standard or check reveal applications.

Frame Offering
  • Suitable for cavity widths of: 75mm, 100mm, 125mm & 150mm
  • Flat option on all widths
  • 75mm & 125mm options for check reveals
  • One piece overhead vent section with deep inner reveal to suit all head construction details and recessed outer grill
Additional Features
  • 100% recycled material, no finish required
  • The Duraframe Cavity Closer system benefits from achieving BBA certification (cert ref. 04/4092). Comprehensive test data can be found in the certificate obtainable from either Duraflex or via

At Duraflex our experienced in-house support team provides a ‘one stop’ service for resolving your technical enquiries – from industry regulations and accreditation changes to product information.

  • Technical Assist dedicated Support Team
  • Assistance with factory layouts and planning
  • Wind loading calculations and advice
  • Accreditation, Regulations & Standards advice
  • In-house Thermal Calculations - fully approved simulators

We also have a dedicated team of mobile service engineers covering the UK and Ireland bring their expertise to suit your needs by providing tailored on-site support to assist your company.

technical support
technical support
technical support
technical support


Benefit from the ultimate Diamond Suite system range of profiles, supported with our complete fabricated product service.


High performing, multi-chambered range of window and door products - designed for today's consumer.


Be inspired with our complete marketing and sales support solution, designed to help grow your business.


Benefit from access and support from our industry leading experts. All here to support your business needs.


From the first meeting to your first day of production and beyond, our changeover team will be at your side.


We seek excellence in every aspect of business and set the same standards in our commitment to the environment.