Cavalok Cavity Closers 50mm to 100mm


The high-performance, no-hassle way to create openings in new buildings 

Specifying the Cavalok cavity closer takes all the hassle and uncertainty out of creating windows and door openings in new buildings. You will be able to quickly create precise, rigid, robust openings that are fully compliant with Building Regulations – saving you time and money in the construction process.

cavalok 100mm cavity closercavalok 100mm cavity closer
cavalok 100mm insulated cavity closer
Cavalok frame former fabrication
Cavalok cavity closer frame fabrication

First choice for 50mm-100mm cavity walls
The Cavalok cavity closure system is designed to create window and door openings while sealing cavities between 50mm and 100mm wide. It is fully compatible will all types of building, whether masonry, steel or timber-framed, and with PVC-U, wood, metal and composite windows and doors.

Quick and easy to fabricate and fit
The simple slot-together system is easy to fabricate and fit to create a rigid bricklaying template and accurate, square window or door acceptor.

Thermally efficient, sustainable solution
With built-in insulation, the Cavalok cavity closer delivers enhanced thermal efficiency to meet current Building Regulations. It’s also manufactured entirely from post-consumer recycled PVC-U – for a complete sustainable solution.

Steel and Timber Frame Construction
Cavalok's patented Framehanger bracket is available for fixing cavity closers to steel or timber frames before the brick skin is built.

Approved system for your peace of mind
The Cavalok cavity closure is fully NHBC and BBA approved as a closer and acceptor, and complies with Building Regulations and Accredited Construction Details (ACDs).

Why choose the Cavalok cavity closer?

  • Manufactured from 100% post-consumer recycled PVC-U – the sustainable cavity closer solution
  • Insulates and seals cavities around windows and doors – improving thermal performance and eliminating draughts
  • Quick and easy to fabricate and fit, with straight cuts and slot-together fitting – saving time and money
  • Creates a rigid template for bricklaying, with no need for dummy formers – providing an accurate, square opening every time
  • Tough, robust design – able to withstand the most demanding site conditions
  • Universal design – accepts all window systems
  • Extensive range of fitting options – to suit every building project
  • Fully approved by BBA and NHBC, and compliant with all the latest Building Regulations – for your peace of mind.


Our Recycling Process

See how we take post consumer waste and recycle it into our sustainable PVC-U Cavity Closer.

Cavalok in action

Browse our case studies to see the Cavalok range in use.