Frequently asked questions
Answers to your cast-in fire collar questions
Can’t see your question? Our technical team is here to help.
Product and specification
What a cast-in collar is, the pipes and slab depths it suits, and the figures you need to specify it.
A cast-in collar is designed into the slab before the concrete is poured. It is fixed to the formwork and cast in place, so the firestop is integral to the structure. A retrofit collar is fitted around the pipe after the slab is built, taking up valuable head height and requiring specific concrete anchors.
In normal use the collar sits cast into the slab around the pipe. In a fire, the nylon fuse-links holding the springs melt, and the loaded springs compress the Intumesh™ intumescent around the softening pipe. As the pipe collapses, the intumescent swells to fill the opening and seals the penetration, maintaining the slab’s fire resistance for the period classified for that pipe and configuration. The patented spring activation is what lets it close fast.
Sure Snap collars are tested with a wide range of plastic pipes, including PVC, HDPE, PP and PE-X, plus certain named systems. The three collar sizes cover nominal pipe diameters up to 160mm. The exact diameter range that is covered depends on the pipe type, so always check the appropriate approval before you specify.
It depends on the collar, the pipe type and the pipe diameter, so there is no single headline figure. Across the range, Sure Snap can provide solutions up to EI 240. Performance is set by the test evidence, which must match the classification for your specific configuration.
The standard collar height is 250mm. For slabs deeper than 250mm, add stackable extensions in 50mm increments. For slabs down to 150mm thick, Selkent offers bespoke collar heights to suit your slab depth. Any trimming on site must follow the installation instructions; do not otherwise cut or modify the collar.
The Manifold Recess Former (MRF) is an accessory for the H110S collar. It recesses the collar up into the slab so a pipe manifold can sit above it, which reduces the pipework head height below the floor. Use it where a manifold connects several pipes close to the slab.
Certification and compliance
The third party approvals behind Sure Snap and how to specify it on a compliant basis.
Yes. Sure Snap holds LPCB Certificate of Product Approval No. 1833a. The collars were tested by a UKAS-accredited laboratory to BS EN 1366-3.
Yes. The H65S, H110S and H150S collars are listed on NBS Source, so you can pull Sure Snap straight into an NBS specification.
No. You can only use the collar in applications that have been tested or included in the Assessment Report at the given fire rating level. When selecting the collar, consider the pipe type, pipe size and slab thickness together. Refer to the collar product pages for the full list of fire-rated system configurations.
Installation
Fitting the collar correctly on site, from annular-gap sealing to what you must not do.
Sure Snap collars have been tested with fittings pushed up inside the collar for a number of pipe types and diameters. Check the fire rating tables to confirm that the measured pipe wall thickness allows a fitting. Some pipe types are difficult to close, so fittings in those pipes are not covered by testing or assessment.
Yes. For pipes that run close together, Connection Clips join adjacent H110S collars neatly for cluster installs. Check the spacing and configuration against the installation instructions and the fire rating tables for the pipe types involved.
The requirement depends on the size of the annular gap on top of the slab.
| Annular gap | Sealing requirement |
|---|---|
| 0 – 20mm | No sealant or grout required. |
| 0 – 20mm | TBC |
| 20 – 50mm | TBC |
| >540mm | TBC |
Cardboard, mineral wool or PE foam can be used as backing material
No. Expanding foam is not to be used in any situation.
No. There should never be any concrete in the spring pockets. Concrete that leaks in during installation can stop the collar activating in a fire, which leaves it non-compliant. The locator plate is designed to block slurry and help keep the pockets clear during the pour.
Ordering and support
Where to buy Sure Snap in the UK, on-site training, and where to find the technical downloads.
The fuse-link is the nylon link holding the spring ends together. If it breaks after the pipe has been installed, the fire collar is still compliant and no further action is needed.
Sure Snap is supplied and supported in the UK by Selkent, the sole UK distributor. Selkent holds stock and provides technical and specification support. Call 020 8699 6777 or email sales@selkent.com.
Yes. Selkent offers free on-site toolbox talks delivered by its technical sales team, so your installers can learn the correct cast-in method before the pour. Get in touch to arrange one.
Datasheets, installation guides, fire rating tables, certification and CAD/Revit files are all available to download. Use the drawings page for DWG, PDF and Revit/BIM models, and the compliance section for the fire rating tables and certificates.