General Interior Materials

What this category covers

General interior materials is the residual class for accommodation outfitting items that are real, specified, and inspected, but too varied to justify a category of their own: mounting brackets and clips for wall and ceiling panels, sealants and fire-stopping compounds for penetrations, edge trims and skirtings, adhesives for deck coverings, and small hardware such as panel fasteners and joiner ironmongery. What ties them together is not function but role — every one of them sits at a joint, seam or penetration in the fire and smoke boundary of a bulkhead, deck or ceiling, and a poor choice at any one of those points can undermine a fire rating that the panel or lining material itself achieved on its own.

Main components of the group

• Fixing and mounting hardware — brackets, clips and rails that hold panels to structure while allowing for thermal movement and hull flexing
• Sealants and fire-stopping compounds — intumescent or fire-rated sealants used at pipe, cable and duct penetrations through A- or B-class divisions
• Adhesives — for deck coverings, panel lamination and trim fixing, selected for low flame spread and smoke generation, not just bond strength
• Trims and edge profiles — skirtings, cover strips and corner trims that finish a joint without breaking its fire integrity
• Joiner ironmongery — hinges, catches and small fittings used across cabin and public-space outfitting

Selection criteria

Because these items are used at joints and penetrations rather than as the main fire barrier, the selection question is always whether the item preserves the rating of the assembly it is fitted into, not whether it has a rating of its own. Relevant points are:

• Compatibility with the specific A- or B-class division it is used on — a sealant approved for one bulkhead system is not automatically approved for another
• Smoke and toxicity performance under the applicable fire test procedure, since low flame spread alone is not sufficient in accommodation spaces
• Mechanical compatibility with the panel and structure — expansion, vibration and hull deflection all load fixings over the ship's life
• Ease of inspection and replacement without disturbing the surrounding fire boundary

Regulations and class

SOLAS Chapter II-2 governs fire protection of accommodation spaces, and the IMO Fire Test Procedures Code sets the test methods that materials at penetrations and joints must pass to be accepted as part of an approved A- or B-class division. Class societies require that any penetration through a rated division, however small, is closed with a penetration sealing arrangement type-approved for that division, and yard workmanship at these joints is a routine item at newbuilding and major refit inspection.