Fire Test

This video shows that fire-treated cellulose insulation can provide over 50% more fire resistance than traditional fiberglass insulation.

1,200 Degrees Thermal Test

When exposed to the especially hot blue flame of a blowtorch, celulose insulation refused to ignite, with a light charring being the only external reaction to the contact.

INSU-GREEN Cellulose Insulation Provides Better Fire Protection

  • Meets and Exceeds Building Code Requirements

  • Class A Fire Rating

  • Easy To Install

  • Does Not Irritate Skin

  • Mold and Fungus Resistant

  • Insect and Rodent Repellant

Insulation is an integral part of your home. Depending on the insulation you choose, there may be additional benefits (or dangers) that you may not have considered.

"11 minutes into the burn, the ceiling of the uninsulated house collapsed....10 minutes later the ceiling of the fiberglass house also collapsed. The ceiling of the cellulose house did not collapse until 1 hour and 10 minutes after the burn started."

Insulator's Guide, news account of fire demonstration

Cellulose Insulation Fire Tests


These fire tests provide information relevant to architects, builders, and homeowners. Cellulose insulation is an exceptional thermal and acoustical insulation with excellent fire safety properties.

ASTM E119-98 Tests

Omega Point, an internationally known NAVLAP certifies laboratory, completed ASTM E119-98 Fire Tests on 2" x 4" wood stud walls framed 16" OC with 1/2" Type X gypsum wallboard on both sides. The tests were performed on uninsulated and cellulose insulated wall sections.

The results are shown in figure 1. The cellulose insulated wall section increased the fire resistance of the wall assembly by 77%.

Multiple Wall Configuration Fire Tests

The National Fire Laboratory of the National Research Council of Canada, one of the premier building material fire testing facilities in the world, conducted fire resistance tests on wood and steel framed wall assemblies. The tests were performed on uninsulated, fiberglass, and cellulose insulated wall assemblies (results below). The cellulose insulation consistently and significantly increased the fire resistance of the walls - by up to 78%.

Straight talk about building insulation and fire

Cellulose is the safest and best insulation commonly used in light construction. This is a problem for those selling insulation products that are not as safe and are much less effective. Somehow, they must convince buyers to accept inferior performance. Some sellers of inferior insulation try to do this by frightening buyers.

Maybe you have heard stories about insulation and fire safety. They all have the same theme: "Our material is 'safe insulation', but their product burns and is the cause of many fires." You may have assumed this is information from an authoritative source.

It isn't. These stories come from the glass industry, a small group of companies selling insulation products that can't compete with cellulose in performance or safety.

The Applications

Dry Cellulose (Loose Fill)

Dry Cellulose is generally blown into new or existing walls or ceilings. During installation by this method, the material will settle by as much as 20 per cent and must therefore be permanently supported.

Spray On Cellulose (Wet Spray)

Spray applied cellulose is used for insulating new stud framed walls (drywall) or ceilings during construction. The only difference between this application and the dry cellulose method is the addition of water, and sometimes with an adhesive, to the cellulose while spraying. Wet spraying helps seal cavities against air infiltration and eliminates settling problems.

Cellulose Panels (Batts)

Celulose panels are commonly installed in sidewalls of residential or commercial structures, but can also be installed in rim joists, attics, floors or other hard to insulate areas. They are also very functional where traditional loose fill or sprayed-in cellulose insulation is not practical

Fire & Cellulose Insulation

Cellulose insulation is comprised of 85 percent recycled material, including newspaper, using ammonium sulfate and borate as a fire retardant.

The borate treatment gives the cellulose insulation a very high fire safety rating in terms of combustibility. From a safety standpoint, that’s good news. As a line firefighter trying to deal with a fire in cellulose insulation, that’s not so good news. The low combustibility of the cellulose makes it easy for fires to start, but the fire retardant treatment doesn’t allow them to grow quickly, so they can continue to smolder. Dealing with a smoldering fire in cellulose insulation in attics and walls can be very challenging for firefighters, because our newer technology isn’t always reliable when investigating these fires.

Hiding Fire

When cellulose insulation burns in an attic space or within a wall, it typically burns from the bottom up, and it burns at such low temperatures that even the best thermal imaging camera (TIC) may not pick up the traces of heat. Additionally, when the insulation is blown in, it makes a thick blanket that can hide the signs of fire. So, at first glance, it can be difficult to tell that a fire is even burning.

Cellulose Insulation Helps Control House Fires

Cellulose Insulation has a Class 1 Fire rating. It is treated with fire retardants to meet all federal, state, and local fire safety requirements. The rating applies to the building assembly. Walls with cellulose insulation are one-hour (or greater) fire walls and can help control the spread of fire.

Cellulose insulation, as a Class 1 or Class A material, means it has a flame spread of 25 or less. It also has a very low smoke development index level.

When properly installed, cellulose insulation can help reduce the spread of flames in house and building fires. Some cellulose insulation manufacturers have even qualified two and three hour firewall designs using Cellulose Insulation.

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