Celbar thermal sound insulation

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Celbar - Environmentally friendly acoustic cavity fill

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Fire rated thermal sound insulation

Properly insulating and air sealing your home is one of the quickest, easiest and most cost effective steps you can take to significantlly reduce your heating bills.  Celbar loft, ceiling and wall insulation effectively reduces sound and heat transfer by creating dead air spaces between and within its fibres.  

Celbar is a recycled, thermal sound insulation made from natural, paper based fibres.   These natural fibres are combined in a unique process with the highest quality fire retardants.  Celbar is UL rated for flame spread and smoke developed with the highest available rating.  A specially formulated borate compound gives Celbar fire resistant insulation a Class 1 fire rating.  Additionally, Celbar thermal sound insulation provides a barrier that resists penetration by fire.

Celbar - Environmentally friendly acoustic cavity fill

How Celbar works

Celbar thermal sound insulation can either be sprayed into a ceiling/wall cavity before the void is closed OR where a void is already closed it is blown by a hose through holes to improve the acoustic insulation of walls and/or ceilings.  This seals any holes and cracks in the wallboard, around electrical outlets, plumbing and other irregularities so there are no compressed areas or voids to allow sound leaks or air infiltration.  When two layers of plasterboard are used, the Celbar sound insulation is blown in before the second layer is fitted.

Celbar is used as a cavity filler in walls and between floors either in conventional rigid construction or with isolated ceiling systems e.g. combined with one of our Oscar Iso-Mount range for ultimate ceiling soundproofing performance.

View Oscar Iso-Mount range

Celbar vs man-made mineral wool

Tests have shown that when packed together this natural, cellulose sound insulation material is both acoustically and thermally more effective than man-made mineral wool.  Consider a wooden rod versus a glass rod over a heat source.  The glass rod conducts heat readily, the wooden rod doesn't.  Traditional mineral wool insulation is a mass of small glass rods, additional insulating power is lost when it is compressed and it is umcomfortable to work with. 

Thermal performance guide filling floor void space, typical < U = 0.25 W/m2K.

Lofts, ceilings, walls and floors are insulated quickly and efficiently with Celbar thermal sound insulation.

Celbar - Environmentally friendly acoustic cavity fill

Thermal sound insulation testing

Celbar acoustic sound insulation provides superior sound transfer control demanded by designers, owners and occupants.  Older properties with ornate ceilings benefit with Celbar acoustic sound insulation blown into the ceiling void reducing noise from rooms above.  It is blown into the void through small holes cut into flat areas of the ceiling and repaired afterwards or if major refurbishment is taking place it is filled from above by lifting floorboards.
*Acoustic performance guide filling floor void space, typical overall improvement better than - 9dB*

A simple wall construction of 63mm thick metal studs lined with 12mm plasterboard on each side was tested:

[a] with no sound control material used - Result 31 STC
[b] with mineral wool sound barrier batt - Result 33 STC
[c] with 38mm of sprayed Celbar - Result 49 STC 


For the ultimate thermal sound insulation and soundproofing solution use Celbar in conjunction with our Oscar Iso-Mount range

View Oscar Iso-Mount range

Recycled thermal sound insulation

Celbar is a naturally safe and recycled cellulose fibre.  The fibre in Celbar acoustic, thermal, sound insulation is organic cellulose derived entirely from recycled macerated paper and treated with a borax compound to protect against fungus, insects and rodents.  It also has fire protection built in.  Celbar cavity fill sound insulation has excellent thermal resistance and provides a high degree of thermal insulation.  Its recycled material and low manufacturing energy requirements combine to produce one of the most environmentally friendly materials used in building construction.

  • Low embodied energy
  • Good for the environment
  • Easy disposal
  • Recyclable

Disposal of Celbar

Reconstruction of a building may necessitate removal of Celbar thermal sound insulation.  It can be recycled or disposed of as a non-special waste to landfill.  Your local authority waste disposal will give advice on recycling. 

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Celbar thermal sound insulation installations

Environmentally friendly insulation

Environmentally friendly insulation

Celbar is a recycled acoustic thermal insulation made from paper based materials and treated for fire retardancy. 

Celbar thermal sound insulation technical specification

Health & safety

There are no known serious risks to health associated with Celbar recycled acoustic thermal sound insulation.  It is non-carcinogenic and any small release of fibre during installation or subsequent maintenance work is not hazardous or considered a ‘Health and Safety’ risk.  Celbar cavity fill insulation is not subject to legislation applicable to mineral or vitrified fibre.  As an added bonus, Celbar cavity fill insulation is non-itchy!


Celbar is manufactured by ICC, Houston, Tx 
ISO 9001: 2000 certification

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