Timloc Thermo-loc FR60 Fire Rated Cavity Closer 50mm (Pack of 5)

The Timloc Thermo-loc FR60 is a fire rated cavity closer designed to seal the cavity at external door and window openings in masonry construction. It achieves a verified 60-minute fire rating and a minimum 15-minute insulation rating, independently tested by Warrington Fire. For any project where Building Regulations compliance is not optional — which is most of them — this is the product that closes the gap, literally and technically.

Cavity closers are easy to overlook on a schedule, but leaving a cavity open at reveals and sills creates three distinct problems: fire spread through the cavity, cold bridging at the perimeter of the opening, and moisture ingress without a proper DPC. The FR60 addresses all three in a single component, which saves time on site and simplifies the sign-off process.

Where the Timloc FR60 Fire Rated Cavity Closer Is Used

This closer is installed at external door jambs, window jambs, and sills where the cavity wall meets the opening. It works with standard masonry cavity construction and suits cavities from 50mm to 100mm in the single profile configuration. For wider cavities between 105mm and 150mm, a double profile version is available in the full Thermo-loc FR60 range.

The FR60 also functions as a DPC at these junctions, integrating damp protection into the thermal and fire barrier in one go. For fully rebated or check reveal applications, dedicated cavity barrier profiles are available separately.

Compliance and Testing

The Timloc Thermo-loc FR60 is compliant with Building Regulation Approved Documents B, C, L1, and L2. It also satisfies the BRE document on thermal insulation and avoiding risks. On projects where Building Control will want to see evidence of fire cavity barrier specification, having a product independently tested by Warrington Fire means the paperwork is straightforward. The test data is already there.

Thermal performance matters here too. Cold bridging at window and door reveals is a common weakness in otherwise well-insulated walls. The FR60 provides continuous insulation around the perimeter of the opening, reducing heat loss at one of the most thermally vulnerable points in a masonry wall. This contributes directly to compliance with Part L and helps avoid the condensation and surface mould that cold bridging can cause internally.

Fixing ties for the FR60 are available separately in packs of 100, which is worth ordering alongside if you are fitting out a full elevation. The closer is designed for efficient site installation and suits the workflow of bricklayers working ahead of the window or door frame being set.

The FR60 50mm variant in this listing comes as a pack of 5. For larger quantities or other sizes across the full range, contact the team for pricing and availability. It is a product where getting the size right the first time matters, so double-check the cavity width before ordering.