FSM - Fire Stop Mortar

VITCAS FSM Fire Stop Mortar – Fire Stop Sealing Mortar for Service Penetrations

VITCAS FSM Fire Stop Mortar is a specialist fire stop sealing mortar developed for passive fire protection applications in fire-resisting walls and floors. It is used to form a rigid seal around compatible building services passing through compartment walls, floors and other fire-separating constructions, helping to reinstate the continuity of the fire barrier around the penetration.

Openings created for electrical, mechanical and other building services can compromise fire compartmentation if they are not protected with a suitable tested fire stopping system. VITCAS FSM is intended for use as the mortar component of an appropriate penetration sealing solution, filling the space around services and creating a robust, stable barrier once cured.

Key Features and Benefits

• Purpose-designed for fire stopping: suitable for forming rigid penetration seals in passive fire protection applications.
• Supports effective compartmentation: helps restore the fire-resisting function of walls and floors where service openings have been created.
• Suitable for service penetrations: may be used around compatible cables, cable bundles, cable trays, conduits and non-combustible pipework where covered by the relevant tested system.
• Rigid cured finish: produces a solid and durable seal suitable for permanent fire stopping installations.
• Versatile application: suitable for appropriately specified openings in fire-resisting wall and floor constructions.
• Professional dry-mix format: mixed with clean water on site to the consistency required by the manufacturer’s installation instructions.

Typical Applications

VITCAS FSM Fire Stop Mortar is intended for professional fire stopping work around service penetrations and openings such as:

• Electrical cables and cable bundles
• Cable trays and cable ladders
• Electrical and mechanical service penetrations
• Non-combustible metal pipework
• Mixed-service openings where the complete tested system permits mortar sealing
• Blank or partially filled openings where included within the approved system configuration
• Service risers and technical areas requiring restoration of fire compartmentation

Note: combustible pipes, insulated pipework and certain mixed-service penetrations may require additional tested fire stopping products such as intumescent wraps, collars or other proprietary components. The mortar must not be assumed to provide a complete fire stop solution for every penetration type on its own.

How Fire Stop Mortar Works

A fire-resisting wall or floor is designed to restrict the passage of fire through a building for a specified period. When services penetrate that construction, the opening around them becomes a potential route for fire and hot gases. A correctly specified fire stop mortar closes the residual opening around the services and forms part of a tested penetration seal designed to maintain the required compartmentation performance.

Unlike ordinary building mortar, a dedicated fire stopping mortar is selected and installed as part of a passive fire protection system. The performance of the completed seal depends on the complete installation, including the wall or floor type, opening dimensions, service material and diameter, seal depth, spacing between services and any additional fire stopping components.

Installation Guidance

Before application, ensure that the opening and surrounding substrates are sound and free from loose material, dust, oil, grease and other contamination that could affect adhesion. Services should be correctly positioned and supported before the fire stop is installed.

Mix VITCAS FSM Fire Stop Mortar with clean water strictly in accordance with the current product instructions. Apply the prepared mortar so that the full required seal depth is achieved and voids around services are completely filled. Where temporary or permanent shuttering, mineral wool backing, reinforcement or additional penetration protection is required, these components must be installed exactly as specified in the relevant tested detail.

Do not rely on general-purpose installation dimensions. Fire resistance is achieved by the complete tested fire stopping system, not by the mortar in isolation.

Fire Stopping for Cables and Pipe Penetrations

VITCAS FSM is particularly suited to projects where a strong, rigid penetration seal is required around compatible mechanical and electrical services. Typical locations include commercial buildings, residential developments, plant rooms, service risers, industrial premises and other buildings where fire compartment walls and floors are penetrated by building services.

For plastic or other combustible pipes, an approved intumescent device may be required to close the opening created as the pipe softens or burns away during fire exposure. Likewise, insulated metal pipes, large cable bundles and mixed penetrations must be checked against the relevant system documentation before installation.

Specification and Compliance

Fire stopping products should always be selected on the basis of tested evidence for the actual application. Before specifying or installing VITCAS FSM Fire Stop Mortar, verify the current technical data, classification or assessment documentation for the required wall or floor construction, penetration type, service size, opening dimensions and target fire resistance.

Installation should be carried out by competent personnel in accordance with the project fire strategy, manufacturer’s instructions and the applicable tested system detail.

Frequently Asked Questions

What is VITCAS FSM Fire Stop Mortar used for?

It is used to form rigid fire stop seals around compatible service penetrations and openings in fire-resisting walls and floors as part of a specified passive fire protection system.

Can it be used around cables and cable trays?

It can be used around compatible cable and cable tray penetrations where the installation is covered by the relevant tested fire stopping detail.

Can fire stop mortar be used around plastic pipes?

Not necessarily on its own. Combustible pipes commonly require an approved intumescent wrap, collar or another tested component in combination with the mortar. Always follow the system-specific detail.

Is fire stop mortar the same as ordinary cement mortar?

No. Fire stop mortar is a specialist passive fire protection product intended for tested penetration sealing systems. Ordinary masonry mortar should not be substituted for a specified fire stopping product.

Does the mortar alone determine the fire rating?

No. The fire performance applies to the complete tested system, including the supporting construction, services, opening size, seal dimensions and any additional fire stopping components.