Mortar (firestop)

Firestop mortar tested to DIN 4102, proven to hold ferrous cable trays in place, when in heat induced motion, pressuring a seal

Cross barrier made of firestop mortar in a German power plant.

Firestop mortars are most typically used to firestop large openings in walls and floors required to have a fire-resistance rating. They are passive fire protection items. Firestop mortars most often exhibit densities near 1 kg/L. This makes the product easy enough to handle, yet heavy enough to absorb a lot of heat from penetrants, to keep the unexposed side of the assembly cool.

Firestop mortars differ in formula and properties from most other cementitious substances and cannot be substituted with generic mortars without violating the listing and approval use and compliance.

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  Firestop mortar, starts as a powder, is mixed with water, forms cement stone, dries hard, is often leavened with lightweight aggregates, such as perlite or vermiculite and pigmented to distinguish it from generic materials in an effort to prevent unlawful substitution and to enable verification of the certification listing. For instance, Nelson CMP is pigmented red and 3M Fire Barrier Mortar is pigmented blue for that purpose.
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  Firestop mortar being dumped into trash bin for mixing with potable water, using drill and mudwhip. Larger installations use mixer/feeder pumps, but small firestop jobs use drill and paddle.
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  20 kg bags of firestop mortar are mixed at once for immediate installation.
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  Firestopped cable tray penetration. The cables and the tray are penetrants.
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  Cable tray cross barrier firestop test, full scale wall, in Germany as per DIN4102.
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  Positive displacement mixer/feeder firestop mortar pump. The premixed dry powder is dumped into the hopper and fed by a screw towards a rotor/stator assembly. To the left of the assembly, the dry powder is mixed with water by paddles welded to the feeder shaft. The resulting paste is then pulled and squeezed through the rotor/stator assembly and into the hose.
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  Detail from a fire test: Proven repair procedure for re-entry and resealing of firestop mortar.

See also

• Mortar
• Perlite
• Vermiculite
• Cement
• Firestop
• Fire test
• Passive fire protection
• Listing and approval use and compliance
• Penetrant
• Fire-resistance rating
• Certification listing

External links

• Article on firestop mortars