Thermo-loc FR30 30 Minute Fire-Rated Cavity Closer (pk 10)

The Thermo-loc FR30 30 Minute Fire-Rated Cavity Closer does three jobs in one component. It closes the cavity around openings, stops cold bridging at the reveal, and provides a damp proof barrier. It also holds back fire for half an hour, which is the part building control tends to ask about. This pack is the single profile version for 50mm cavities, ten closers to a pack.

Cold bridging is the sort of problem you only notice once the plaster is on and the customer is complaining about black mould in the corner of a bedroom. A masonry closer or a lump of mineral wool st￭ in the gap will not do the same job. The FR30 sits in the cavity at the jamb or sill and gives a continuous thermal break exactly where heat wants to escape.

Where the Thermo-loc FR30 Fire-Rated Cavity Closer Gets Used

On masonry walls, mainly. External door openings, window jambs, window sills. Anywhere the cavity would otherwise be left open or bridged with something that conducts heat and moisture across to the inner leaf. The FR30 is designed for cavities up to 300mm across the range, with single profile versions covering 50mm to 100mm and double profile versions covering 105mm to 300mm. For a standard 50mm cavity, this single profile is the one you want.

It has been independently tested by Warrington Fire. The result is 30 minutes fire rating with a minimum of 15 minutes insulation. That matters on projects where the cavity runs around openings in fire compartment walls or where the spec calls for fire stopping at the perimeter of an opening.

Building Regulations

The closer is compliant with Approved Documents C, B, L1 and L2, and it satisfies the BRE document on avoiding thermal insulation risks. In plain terms, one product covers moisture, fire and thermal performance, which saves you ordering three separate things and arguing about which one the inspector will accept.

If you need the range for other cavity widths, or the rebated and check reveal cavity barriers, they are available separately. Fixing ties come in packs of 100. Ten closers per pack is a sensible quantity for a typical house build or a run of openings on an extension, and it keeps the price per closer well below buying loose.

For a full list of sizes or a bulk quote on larger orders, get in touch. Stock moves quickly on the common sizes, and a pallet order is usually cheaper than you would expect.