ISL Therm-A-Strip Glazing Seal – 2100mm is a flexible, self-adhesive intumescent strip suitable for use within approved fire-resistant glazing systems and other closely controlled fire-sealing applications.
The strip is manufactured from a phosphate-based intumescent material that remains flexible during normal conditions. When exposed to elevated temperatures, it expands to help fill gaps and restrict the passage of flames and hot gases through the protected area.
The stocked range is supplied in three profile sizes:
Every option is supplied in a fixed 2100mm length with a White finish.
Therm-A-Strip combines the fire-sealing properties of an intumescent product with the handling benefits of a flexible strip.
Within a supported glazing arrangement, it can be positioned between specified glazing components to help protect gaps around the fire-resistant glass.
The flexible construction allows the strip to:
The strip must be installed in the location and orientation required by the fire-door, glazing-system or assessment evidence.
Therm-A-Strip is described as a low-pressure intumescent material.
This makes it suitable for applications where a more forceful pressure-forming product could be unsuitable. The moderate expansion pressure helps the material fill available spaces while providing resistance to erosion during fire conditions.
When heated, the material:
The available expansion space and installed strip dimensions must follow the supported construction.
The supplied product is sold as a glazing seal and may be used within approved glazed apertures in suitable fire-resisting doors and screens.
A complete fire-glazing system may also require:
Therm-A-Strip must not be treated as a complete glazing system by itself.
Before using Therm-A-Strip within a fire-resisting door, confirm that the supporting doorset evidence permits:
Cutting a glazed aperture into a certified fire door without suitable evidence may invalidate the certification and fire-performance claim.
The manufacturer states that Therm-A-Strip has been successfully tested as a component within doorsets to the fire-resistance requirements of:
This testing does not give every Therm-A-Strip profile a universal standalone fire rating.
The achieved performance depends on the complete assembly, including:
The stocked Therm-A-Strip profiles are supplied in a self-adhesive format to simplify positioning during assembly.
The adhesive backing helps hold the strip against a suitable glazing bead or other approved surface while the remaining glazing components are installed.
The adhesive does not:
The stocked range is supplied in White.
The manufacturer describes the standard material as having a natural white finish that is resistant to atmospheric moisture and carbon dioxide. It therefore does not normally require additional surface protection.
The material may be compatible with conventional decorative finishes, but any painting or coating within a certified glazing system should first be checked against the applicable evidence.
The current stocked profiles are:
The three widths are not automatically interchangeable.
Select the profile specified by the glazing-system detail rather than choosing solely according to the available space.
Each product is supplied as one 2100mm strip.
The quantity required depends on:
Measure the full glazing perimeter before calculating the required number of lengths.
Therm-A-Strip can also be produced for applications where a flexible, low-pressure intumescent gasket is required.
Potential supported uses include protection around:
This product listing should nevertheless be selected and installed as the specified glazing-seal configuration.
Before ordering, confirm:
Do not select or substitute the strip solely by its physical dimensions.
| Product Name | ISL Therm-A-Strip Glazing Seal – 2100mm |
| Manufacturer | Intumescent Seals, a division of Dixon International Group Ltd |
| Product Range | Therm-A-Strip |
| Product Type | Flexible low-pressure intumescent glazing strip |
| Material | Phosphate-based intumescent material |
| Stocked Widths | 10mm, 15mm and 20mm |
| Thickness | 2mm |
| Length | 2100mm |
| Colour | White |
| Fixing Format | Self-adhesive backing |
| Expansion Pressure | Low pressure |
| Published Expansion | Approximately ten times the original volume |
| Activation Temperature | Approximately 180°C |
| Test Evidence | Tested as a component within doorsets to BS 476 Parts 20 and 22 |
| Standalone Fire Rating? | No — performance depends on the complete tested or assessed construction |
| Standalone Smoke Classification? | No separate cold-smoke classification should be assumed |
| Standalone Acoustic Rating? | No |
| Profile Size | Length | Colour | Product Code |
|---|---|---|---|
| 10 × 2mm | 2100mm | White | THSTRIP/10X2/A |
| 15 × 2mm | 2100mm | White | THSTRIP/15X2/A |
| 20 × 2mm | 2100mm | White | THSTRIP/20X2/A |
| Width Options | Thickness Options | Length Options | Colour Options | Total Variations |
|---|---|---|---|---|
| 10mm, 15mm and 20mm | 2mm | 2100mm | White | 3 |
The stocked Product Codes use the following format:
THSTRIP / Width × Thickness / Backing
The manufacturer’s information sheet also lists standard widths of:
These additional profiles are not included within the current selectable stock range for this product.
Fire performance depends on:
Store Therm-A-Strip:
Do not install material that is:
Therm-A-Strip must be installed in accordance with the tested or assessed glazing-system detail.
The manufacturer does not prescribe one universal glazing position, bead construction or fixing arrangement for every application. Confirm the complete specification before cutting or applying the strip.
Confirm:
Do not modify a certified fire door unless the proposed glazed aperture is supported by current evidence.
Check that the prepared opening is:
Stop work if the exposed construction does not match the expected doorset or screen specification.
Prepare the glazing beads, aperture liners and setting blocks according to the supporting evidence.
Confirm that the selected Therm-A-Strip width corresponds with the approved glazing detail.
Do not:
The surface receiving the self-adhesive strip must be:
Allow any suitable cleaning product to dry completely.
Establish whether the approved system requires the strip to be applied to:
Do not assume that the same position applies to every fire-door or screen system.
Measure the first bead or aperture side.
Transfer the measurement to the Therm-A-Strip without stretching it.
The cut length should meet the adjoining section closely at the corner.
Cut the material cleanly using sharp scissors or a suitable knife.
The cut should be:
Do not pull or stretch the material while cutting.
Peel back a short part of the adhesive release liner.
Align the strip with the required installation position and press it firmly against the prepared surface.
Remove the liner progressively while working along the strip.
Do not:
Measure, cut and apply each remaining strip section.
At the corners:
Before installing the glass, check for:
Replace defective sections before continuing.
Fit the specified setting blocks in the positions required by the glazing-system evidence.
The setting blocks support the glass and maintain the required edge clearances.
Therm-A-Strip must not be used to support the weight of the glass.
Install the approved fire-resistant glass using suitable handling equipment.
Check that:
Position and mechanically secure the glazing beads according to the approved glazing detail.
Confirm that:
The self-adhesive backing does not replace the required mechanical bead fixings.
Inspect both faces of the completed glazed aperture.
Confirm that:
Inspect the glazed aperture as part of the doorset or screen maintenance programme.
Check for:
Therm-A-Strip does not independently provide a universal fire-resistance period.
Performance depends on the complete tested or assessed system, including:
Install the product only in accordance with current fire-test evidence, assessments, certification and the instructions applicable to the complete construction.
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