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Closing gaps around window and door reveals is essential to stop thermal bridging, eliminate damp condensation and prevent heat loss. Installing a trade-quality cavity closer alongside your cavity wall insulation creates a continuous thermal seal, keeping properties warm and energy-efficient.

At Wickes, we supply a range of cavity closers to fit cavity sizes from 50mm to 150mm. Our universal closers work seamlessly across both timber frame and traditional masonry walls.

FAQs

What is cavity wall insulation?

Cavity wall insulation is material installed inside the gap (cavity) between a building’s inner blockwork and outer brickwork. It works by trapping air to significantly reduce heat loss through external walls, making homes warmer, more energy efficient and cheaper to heat.

What is a cavity closer?

A cavity closer is an insulated rigid structure used to seal the open cavity around window and door reveals. It acts as a thermal break between the internal and external walls, preventing draughts, heat loss and internal damp condensation around openings.

How easy is it to cut a cavity closer?

Very easy. Many designs feature convenient pre-cut grooves that allow you to trim the profile down on-site using a fine-toothed hand saw or a utility knife to match your exact wall width. If yours does not have pre-cut grooves, simply measure your gap and mark a straight line with a pencil.

How to fit cavity closers

To fit a universal closer, follow these steps:

1. Measure your cavity width 
2. Snap or cut the pre-grooved insulation to size using a utility knife.
3. For new builds, position the profile directly into the reveal as masonry work progresses using wall ties in the mortar bed

For refurbishments or retrofits, friction-fit or fix the profile into the exposed cavity before installing windows or door frames.

What tools do I need to fit cavity closers?

Fitting a cavity closer requires only basic hand tools:

• A tape measure to calculate cavity width and height.
• A sharp utility knife or fine-toothed hand saw to cut the pre-grooved EPS insulation and PVC extrusion.
• A pencil for marking cuts.
• Brick ties (for new builds).
• Grab adhesive or masonry fixings (for retrofits).

How long does it take to fit a cavity closer?

Installing a cavity closer is quick and straightforward. Trimming and fitting a single profile around a standard window reveal typically takes 10-15 minutes. Complete installation for an average sized domestic window opening usually takes under 30-45 minutes.