Description
Dowsil Firestop 700 is a high-performance, fire-rated silicone sealant developed to prevent the spread of fire, smoke, and toxic gases through construction joints and service penetrations.
Tested in accordance with BS 476 Part 20/22, it provides up to 4 hours of fire resistance when correctly installed in approved joint configurations.
This neutral-cure silicone adheres strongly to common construction materials such as concrete, masonry, metals, and glass, forming a flexible, durable seal that remains stable under both high heat and movement.
In addition to its fire-resistant properties, Dowsil Firestop 700 offers excellent weathering performance, making it suitable for internal and external applications on curtain walls, expansion joints, and fire-rated walls or floors.
It’s trusted by contractors and specifiers worldwide as part of a complete firestopping and compartmentation system that meets the most demanding building safety standards.
Benefits
- Fire-rated silicone sealant designed to contain fire and smoke in joints and penetrations
- Resistant to flames, heat, and smoke spread up to 4 hours (tested to BS 476 Part 20/22)
- Excellent adhesion to concrete, masonry, metals, and glass
- Maintains flexibility and weather resistance for long-term durability
- Ideal for firestopping curtain walls, service penetrations, and expansion joints
How to Apply
How to Apply
1. Surface Preparation - Ensure all surfaces are clean, dry, and sound. Remove dust, grease, and loose debris.
- Non-porous substrates (metal, glass): Wipe with Dowsil R-40 Universal Cleaner or equivalent solvent; allow to dry.
- Porous substrates (concrete, brick, stone): Mechanically clean to remove contaminants.
2. Masking - Mask the edges of the joint for neat lines and to prevent over-application.
3. Joint Design - Follow the fire-rated joint dimensions as specified in the Dowsil Firestop 700 test report. Use mineral wool backing or approved fire-rated backing materials to achieve certified performance.
4. Application - Cut the nozzle to the desired width. Gun the sealant into the joint, ensuring complete contact with both faces. Avoid air entrapment. Apply sufficient material to fully fill the void.
5. Tooling - Tool immediately to compact the sealant and create a smooth surface. Remove masking tape before skin formation.
6. Curing
- Skin time: ~20–30 minutes
- Full cure: 48 hours (depending on joint depth and ambient conditions)
Do not expose to water or mechanical stress during curing.
7. Inspection & Maintenance - Allow sealant to cure completely before inspection. Damaged areas should be cut out and re-sealed with fresh product.
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