Firestop for large openings

All you need to know to master the smoke- and fire-sealing of large openings


Take a walk through the plant room of any modern building and you’ll see a maze of layered M&E services which would have been unimaginable a few years ago. This endless array of cables, bundles, trays, conduits, plastic and metal pipes need larger wall and floor penetrations than ever – which presents new challenges for fire compartmentation. You can rely on Hilti Firestop to deliver workable smoke- and fire-resistant sealants around these larger penetrations.

It’s not just the scale of technical installations that has grown, but also the rate of change. Any high-spec project – but especially data centers and hospitals – depends on building services that allow rapid, downtime-free changes. By choosing re-penetrable firestop solutions, you can maintain your ever-changing M&E installations without sacrificing efficiency or safety.

To deliver the adaptability you need in larger openings, we offer traditional firestop mortars, coated board systems, composite sheets and various preformed solutions like fire blocks, cushions and modular transit frames. They are all designed to be easy to specify, install and inspect.


Firestop block CFS-BL

If you expect to upgrade or expand your M&E installations very frequently, preformed solutions – like firestop blocks – are ideal for easily sealing large openings. This non-curing and re-usable solution is designed for high-productivity installation by a single person with no special tools. CFS-BL and CFS-BL P firestop blocks have been designed specifically to simplify re-penetration of retrofitted cables. They can be dismounted, cut and re-installed easily. Firestop blocks also minimize airborne dust and fibers when compared to more traditional solutions like firestop coated boards and mortars

CFS-CU Firestop cushions cable tray

Our preformed, surface-mounted solution – the CFS-BL Firestop Block – has been designed for firestopping mixed openings. Its modular design means that you can combine up to three elements together for the firestopping of opening sizes up to 562 mm. This easy-to-install and inspect, virtually dust-free solution allows for a 100% cable fill on regular and irregular openings. It also allows you to seal old, damaged or incorrectly sealed penetrations – even without removing the existing firestop material in the opening.

The CFS-COS Firestop Composite Sheet is also suited for frequent re-penetrations. Easy to install and cut, it is designed to accommodate single cables, cable trays and multiple cable configurations.


CP 636 CFS-M RG Mortar application with ID plate

If you don’t expect to upgrade or change your M&E installations, then CP 636 firestop mortar is an economical solution for large openings. Mortars create a permanent smoke- and fire-resistant seal around cables, cable bundles, cable trays, plastic and steel conduits and various types of pipes (metal, PVC, PE).

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