Fire retardant sealant, Bostik Fireseal Hybrid FP403, designed to deliver fire resistance in linear joints. Users gain reassurance during safety inspections and handover thanks to certified performance. Does the certification and joint width suit your project's requirements?
⚡ At a Glance
- • Fire Performance: Fire resistance up to four hours in linear joints, tested to EN 1366-4
- • Best for: Installers and contractors needing certified firestopping for linear joints
- • Not ideal for: Applications requiring integrated acoustic or mechanical fixing systems
Certified fire stopping for linear joint applications, including EN 1366-4 testing and ETA 20/1119. Suitable for joints up to 60mm with additional resistance to smoke and weathering.
Up to Four Hours' Fire Protection - with EN 1366-4 testing and ETA 20/1119
EN 1366-4 testing measures fire resistance in linear joint scenarios and the ETA 20/1119 confirms assessed performance under those conditions. Fire classification B-s1,d0 and smoke leakage ratings are reported according to EN standards.
Provides certified compartmentation for up to four hours in appropriate joint configurations, giving confidence during building safety assessments.
Neat, Reliable Application - with non-slump hybrid formulation and 60mm joint capacity
Hybrid chemistry combines elasticity and adhesion while preventing slump, enabling application in joints up to 60mm wide without sagging. The formulation supports use on vertical and horizontal joints where a stable sealant bead is required.
Faster installations and fewer touch-ups, particularly on overhead or wide joints, reducing labour time and rework.
Weather and Smoke Resistance - with UV, water resistance and Sa / S200 rating
Resistance to UV, water and weathering helps maintain seal integrity in exposed conditions, while EN 1634-3 based smoke leakage testing gives a Sa / S200 rating for smoke performance.
Suitable for external and exposed internal locations where both weather resilience and smoke control are required for compartmentation.
✨ The 4 Key Reasons for Bostik Fireseal Hybrid FP403
- Four-hour fire rating - Certified protection for linear joints under EN 1366-4 testing
- 60mm joint capacity - Fills wide joints without layering or multiple applications
- Non-slump formula - Smooth application on vertical and overhead joints with minimal mess
- Weather resistant - Withstands UV, water and weathering for exposed situations
📋 Technical Details at a Glance
- Category: Fire retardant sealant
- Brand: Bostik
- Product ID: B0DWN6HB9C
- Volume: 290ml
- Formulation: Hybrid sealant
❓ Frequently Asked Questions
Q: How long does the sealant resist fire in a linear joint?
A: Fire resistance is certified for up to four hours in linear joints, tested according to EN 1366-4 and covered by ETA 20/1119.
Q: What maximum joint width can be filled?
A: Joints up to 60mm wide can be filled without slumping, allowing single-pass application in many installations.
Q: Is the sealant suitable for external use or exposed locations?
A: Yes, UV, water and weather resistance are specified, and smoke leakage ratings are provided, supporting use in exposed situations.
🏆 Our Verdict
Suitable for installers, contractors and building managers who need certified fire stopping for linear joints. Certified performance, non-slump application and weather resistance combine to deliver reliable compartmentation and easier installation. While initial outlay may be higher than basic sealants, the certified durability and compliance offer strong long-term value.
