The indispensable building component – 100% post-consumer recycled UPVC cavity closers

Cavity closers have become a critical building component that's now widely used in all commercial and residential new-build projects. They are undoubtedly the simplest and most effective way to seal cavities around wall openings and provide a rigid template for bricklaying and window or door installation.

Select from:


Super-insulating Cavity Closers for 125-300mm cavities


Environmentally friendly cavity closer with exceptional fire protection.

Trade Closer

Retro-fit solution for existing walls or pre-determined new-builds.
trade closer

Structural Closer

Works across Passive House Design and CSH requirements.
structural closer


Unobtrusive and eliminating need for unsightly through-frame ventilation.


Lightweight, heat and pressure resistant super-strength technology.

Improving thermal efficiency performance

Our unrivalled range of innovative cavity closers won't just help you meet today's sustainable legislation, but that of the future.

One of the main Cavalok products is BigBlok. A leading insulated cavity closer system designed for zero-carbon buildings, which means it already satisfies the 2016 Code for Sustainable Homes Level 6.

Benefits at a glance:

  • Manufactured from 100% post-consumer UPVC
  • Pre-installed polystyrene core enhances thermal efficiency for Part L compliance
  • Time saving clip together assembly – no adhesives or tools required Quick-fit spring clip for fast installation of pre-glazed windows
  • Compatible with most UPVC window systems as well as timber and aluminium

For more information about the Cavalok range of UPVC products and support services for specifiers and architects, please call 1890 989 071.

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