Our glossary shows a comprehensive list of common terms used in the suspended ceilings field. The terms are grouped with topics of a similar nature for easier navigation. If you can't find your question listed then contact our technical experts.



Other definitions

Sound systems

Systems / Edge details / Installation

Class 1, 10, 100 etc - These are examples of a classification system for a "measured environment" known as a clean room. It limits the amount of particles greater than a specified size within a specified volume of air, using imperial units, as defined by US Fed Standard 209D. This standard (and the classification system) was subsequently superceded by US Fed Standard 209E which expresses limits in metric units and both have now been superceded by an international standard, ISO 14644.

Clean Room - A room for research, product assembly or health care where the air quality for dust, lint, or airborne pathogens is critical. Such areas usually have smooth room surfaces to prevent dust collections and air supply systems using HEPA filters in order to keep dust, lint, etc to a specified minimum level in accordance with ISO 14644.


Durability - High resistance to surface damage - The ability of a ceiling tile to withstand vigorous cleaning, scrubbing or scratching.

Hard (wet felt) Mineral Fibre Ceilings - Ceiling tiles or planks manufactured from a combination of the following naturally occuring, processed and recycled materials in varying proportions depending upon the tile type: mineral wool, clay, perlite, cellulose and starch mixed together in a water based process before being cured by heat. They are then finished with a water based paint, or laminated scrim and paint, decorative facing. Wet felt technology allows considerable variation in the product's density and porosity which can be used to positively influence a wide range of technical performances of the finished products.

Humidity Resistance - A ceiling tiles' ability to withstand levels of moisture without sagging. Standard tiles and panels are designed for installation within a normal occupancy condition range of 15 to 35°C and maximum 70%RH. When temperature and humidity resistance are expected to exceed these ranges, the use of 95% or 100% RH products should be considered.

Hygien - Anti-microbial Treatment - Where strictly controlled hygienic air quality is a project requirement, chemically treated tiles are available. Treament is designed to prevent mould, mildew and bacteria.


Laminated Ceiling Product - A mineral fibre product with decorative surface laminates such as glass wool scrim or polyester film.


Point load - A load applied to a structure which is concentrated over a very small area. For example, the hangers of an information sign suspended below a ceiling grid, impose point loads where they are attached to it.


Soft Fibre Ceilings - A mineral fibre ceiling product manufactured with a high proportion of mineral wool and finished with a painted laminated scrim decorative facing. They are therefore more porous and lower in density than 'hard' mineral wool types and this results in tiles with very high sound absorption although their sound attenuation will be moderate.

Thermal Conductivity (k) - Ability of the material to resist the transmission of heat through it. The lower the reported number, the better is the thermal insulation provided.

Uniformly Distributed Load - A load applied to a structure that is evenly distributed across the area where it is maintained. For example a lay-in ceiling tile imposes a uniformly distributed load along the four flanges of the grid that supports it.
