FZ400: Advanced Fire-Resistant Linear Gap Seal for Dynamic Joints

FZ400 as a Linear Gap Solution

FZ400 is a high-performance linear gap seal designed for fire-rated construction joints in accordance with EN 1366-4. It is suitable for both horizontal and vertical applications, providing a reliable fire-resisting solution for gaps in walls and floors.

Linear gaps are commonly found:

• At the top or edges of walls
• Between wall heads and soffits
• Between floor slabs and structural members
• In any movement-prone joint requiring fire-resistant sealing

FZ400 is specifically engineered for situations where movement capability is required. For static joints, other options such as fire sealants, batts, or standard gap seals may be used. However, FZ400 offers superior movement performance compared to these traditional solutions.

What Makes FZ400 Different?

FZ400 is a graphite-impregnated open-cell foam that expands rapidly when exposed to heat. Its water-resistant film also acts as an effective cold smoke seal, providing both flexibility and robust fire stopping in one easy-to-install product.

Key Features of FZ400

High Movement Capability

Designed to absorb significant joint movement far beyond what standard sealant, batt, or rope-based systems can tolerate.

Fully Tested & Certified

Fire tested to EN 1366-4 for both wall and floor constructions, ensuring dependable and compliant performance even after movement.

Nullifire’s Patented GXT Technology

Combines flexibility and high expansion with superior fire protection, enabling FZ400 to maintain its seal as the building moves.

Simple, Fast Installation

• Installed as a dryfit product
• Works effectively under compression
• Cut-to-size, lightweight, and requires minimal tooling

Zero Fibre Migration

Ensures long-term integrity and avoids contamination within ceilings or voids.

Suitable for Retrospective Fitting

Ideal for refurbishment or where access limitations prevent traditional installation methods.

Typical Benefits

FZ400 delivers consistent fire-resisting performance in dynamic joints, significantly reducing the risk of failure where structural movement occurs. Its dry installation eliminates curing time, enabling fast, clean, and reliable on-site application.

With high movement capability, strong post-movement fire performance, and practical site-friendly installation, FZ400 offers a dependable, modern solution for protecting linear gaps in fire-rated construction.

To learn more or get project specific support, contact hello@tremcocpg.com or reach out to your area sales manager.