Cavity Closers

Choosing the Right Cavity Closers for Windows & Doors

At County Building Supplies, we supply cavity closers for professional builders, contractors, self-builders and DIY customers. Cavity closers are used around window and door openings in cavity wall construction, helping to close the cavity, reduce thermal bridging and provide a suitable finish around openings.

Our range includes Dacatie Multi Cavity Closers in different widths to suit a variety of cavity wall constructions.

What Are Cavity Closers Used For?

Cavity closers are fitted around window and door openings where the inner and outer leaves of a cavity wall meet. They help close the exposed cavity and can contribute to reducing heat loss around openings.

Suitable cavity closers can also help limit moisture transfer at the opening when correctly specified and installed as part of the complete wall and window or door system.

Choosing the Correct Cavity Closer Width

One of the most important considerations is matching the cavity closer to the width of the wall cavity.

• Dacatie Multi Cavity Closer 50-100mm: Designed for compatible cavity widths within the stated 50mm to 100mm range.
• Dacatie Multi Cavity Closer 100-150mm: Designed for compatible cavity widths within the stated 100mm to 150mm range.

Both products are supplied in 2.4m lengths. Always check the manufacturer's technical specifications and measure the actual cavity width before ordering.

Cavity Closers & Thermal Bridging

Thermal bridging occurs where heat passes more readily through part of a building's construction, potentially creating colder internal surfaces.

Insulated cavity closers can help reduce thermal bridging around window and door reveals when incorporated into a correctly designed wall system. Their performance depends on the complete construction and installation details.

Installing Cavity Closers

Cavity closers should be installed in accordance with the manufacturer's guidance and the specified window or door opening details.

Correct positioning, secure fixing and continuity with the surrounding insulation are important. Check any relevant requirements for moisture protection, fire performance and Building Regulations compliance before installation.

How Many Cavity Closers Do You Need?

Measure the sides and top of each window or door opening where cavity closers are required, then add the lengths together.

For example, an opening measuring 1.2m wide and 1.2m high requires approximately 3.6 linear metres for two sides and the head, before allowing for cuts and waste.

With 2.4m lengths available, check your cutting plan carefully to determine the number required.

Need Advice?

Not sure which cavity closer width you need? Visit your local County Building Supplies branch or contact our team for help choosing suitable products, calculating quantities and checking availability.