Foams, light water additives, phosphate clays, and plain water have been the main solutions to the wildfire problem. These products have various degrees of cost and effectiveness.

The most used liquid is water, since it is extremely cheap and is available in large quantities in all but the most arid regions of the country. Water does an adequate job of cooling the fire and thus acting as an extinguishing agent.

Over the last twenty (20) years, a new polymer gel technology has been gaining in popularity in both ground attack and aerial drop on large wildland fires. These polymer gels are non-toxic and break down in the environment causing no deleterious effects to plants or wildlife.

Gels works by encasing beads of water in a polymer matrix. Under heat attack, the water is protected from rapid evaporation by the insulating capability of the polymers. Once the water has finally been driven from the polymer, the remaining dry polymers are broken down after a twenty-eight (28) day cycle from sunlight and other environmental influences.

Polymer gels are tested and fully approved for use in wildland fire fighting applications. They have been flown in aerial direct attacks on live fires and have proven their effectiveness as a major wildfire fighting tool.

Nochar gel technology has been developed for professional fire fighting organizations to equip them with state-of-the-art technology to fight devastating fires.

FIRE SAFE BUILDING DESIGN

Each building design poses varying degrees of fire safety. For example, houses in the northern or more frigid climates designed for energy conservation pose a problem with smoldering fires that consume oxygen and cause carbon monoxide and other problems of toxic gases due to the lack of air exchange. Houses designed for security in metropolitan or high crime areas cause a problem in rapid evacuation or escape. High rise buildings are another type of building that presents some very unique fire safety considerations. Homes in remote areas, houses in densely forested areas and homes in canyons with low dry brush each present different fire risk and safety problems. Consequently, there is no single or simple solution or cure all. The following are illustrations and a detailed discussion of each home design and type of location:

1. Home with a fireplace.

2. Cedar shake roof.
3. Home in a forest setting.

* Reduce heat release rate
* Reduce smoke generation rate
* Prevent unusual toxic hazard relative to quantity of smoke generated

(2) Add fire retardant to materials

* Slow growth of heat release rate

(3) Use fire-resistive barriers

* Slow spread of fire to large secondary items

(4) Restrict total fuel load
*
* Limit contents based on total fuel potential

(5) Restrict linings of rooms to prevent rapid flame spread
* Restrict wall coverings
* Restrict ceiling coverings
* Restrict floor coverings
(6) Restrict materials in concealed spaces

* Restrict concealed combustibles
* Restrict concealed space linings
(7) Require safe handling of large quantities of potential fuel

Nochar’s Fire Preventer (NFP) is neither pressure impregnated nor a surface coating. Although applied to the surface, it is absorbed into the cells of the material being treated. It will last the life of the fibers as long as it is protected from running water.

IMPREGNATION

Wood is pressure impregnated with chemical solutions using full-cell pressure processes similar to those used for chemical preservative treatments. Retentions of the chemicals must be fairly high to be effective. Full-cell pressure impregnation provides the most effective method for getting chemicals into the wood at the high retention levels needed for reduced flame spread. Standards C20 and C27 of the American Wood-Preservers’ Association recommend the treating conditions for lumber and plywood. The wood is usually treated in the air-dried or kiln-dried condition, but certain species may be treated green if the wood is first given a steam treatment for periods of up to 4 hours.

The penetration of the chemicals into the wood depends on the species, wood structure, and moisture content since some species are difficult to treat. The degree of impregnation required to obtain a Class A category may not be possible. Certain wood species are incised prior to treatment to improve the depth of penetration. Knife checks and end grain at panel edges improve the ease of impregnation on sheets of plywood, thus eliminating the need for incising. With water-soluble impregnation, only exterior grade wood should be used to prevent the plies from delaminating.

After wood is removed from the treating solution, it must be carefully dried and, in certain cases, cured under the proper conditions. Various laboratories perform fire performance rating tests on these treated materials and maintain lists of products that meet certain standards.

The act of impregnation by the use of positive pressure, combined with the chemicals and final kiln drying, seems to cause degradation of strength of the material being treated. nochar’s Fire Preventer NFP) treatment is either a shell loading chamber process or surface application through spray or dipping. In either case, the chemical loading is not sufficient to cause fiber deterioration nor does it need to be kiln dried. nochar’s Fire Preventer (NFP) is virtually inert and does not activate through heat, which can cause more fiber destruction. nochar’s Fire Preventer has very low hydroscopic properties, therefore, does not tend to leach out due to humidity or moisture. The product will only leach as a result of an abundance of running water.

Coating

Many commercial coating products are available to provide varying degrees of protection to wood against fire. These coatings generally have low surface flammability characteristics and “Intumesce” to form an expanded low density film upon exposure to fire. This film insulates the wood surface below from high temperatures. Also, coatings have ingredients that restrict the flaming of any released combustible vapors. These formulations may contain chemicals that promote the rapid decomposition of the wood surface to charcoal and water rather than forming intermediate volatile flammable products.

Comparative effects of fire on various materials

Fire is the largest single cause of destruction of buildings and the materials from which they are constructed.  Some materials gradually lose their cross-section by burning, some soften and lose strength, and others crumble when exposed to high temperatures. Such temperatures occur during all building fires, and frequently exceed 1,000°F within a few minutes after the fire has started.

Let’s compare what happens. At a temperature of 150°F, usually reached within (5)-minutes, structural building materials will not be ignited but beyond this temperature, human evacuation will be impeded. Before this temperature is reached, smoke from burning contents usually makes the building uninhabitable.

At 572°F, most aluminum alloys are reduced to half their strength and melt at about 1,112°F. Steel has a little less than half its breaking strength at 1,022°F, and loses 90% of its structural strength at 1,382°F.

Ordinary  untreated  wood does not begin to burn until a temperature of 523°F is reached, and fire retardant treated wood will only begin to char. Wood loses its strength in a different way than metals. In the early stages of a fire, it is quite likely that its unit strength is increased because of reduced moisture content. Wood is a good insulator and does not transfer the heat on its surface to its core very quickly. While it may be burning or charring on its surface, its interior will be relatively cool for a long time. All this increases the length of time wood and fire retardant treated wood will retain its integrity – time to get the people out of the building, time to get the firemen to the building and time to extinguish the fire. Fire retardant treated wood has the added advantage of maintaining structural integrity even longer because it chars at a slower rate than untreated wood is consumed.  In addition, fire retardant treated wood will not spread the fire from one portion of a building to another, and it will extinguish itself once the ignition source is removed.

Nochar’s Fire Preventer (NFP) is neither pressure impregnated nor a surface coating. Although applied to the surface, it is absorbed into the cells of the material being treated.  It will last the life of the fibers as long as it is protected from running water.

IMPREGNATION

Wood is pressure impregnated with chemical solutions using full-cell pressure processes similar to those used for chemical preservative treatments. Retentions of the chemicals must be fairly high to be effective. Full-cell pressure impregnation provides the most effective method for getting chemicals into the wood at the high retention levels needed for reduced flame spread. Standards C20 and C27 of the American Wood-Preservers’ Association recommend the treating conditions for lumber and plywood. The wood is usually treated in the air-dried or kiln-dried condition, but certain species may be treated green if the wood is first given a steam treatment for periods of up to 4 hours.

The penetration of the chemicals into the wood depends on the species, wood structure, and moisture content since some species are difficult to treat. The degree of impregnation required to obtain a Class A category may not be possible. Certain wood species are incised prior to treatment to improve the depth of penetration. Knife checks and end grain at panel edges improve the ease of impregnation on sheets of plywood, thus eliminating the need for incising. With water-soluble impregnation, only exterior grade wood should be used to prevent the plies from delaminating.

After wood is removed from the treating solution, it must be carefully dried and, in certain cases, cured under the proper conditions. Various laboratories perform fire performance rating tests on these treated materials and maintain lists of products that meet certain standards.

The act of impregnation by the use of positive pressure, combined with the chemicals and final kiln drying, seems to cause degradation of strength of the material being treated. nochar’s Fire Preventer NFP) treatment is either a shell loading chamber process or surface application through spray or dipping. In either case, the chemical loading is not sufficient to cause fiber deterioration nor does it need to be kiln dried. nochar’s Fire Preventer (NFP) is virtually inert and does not activate through heat, which can cause more fiber destruction. nochar’s Fire Preventer has very low hydroscopic properties, therefore, does not tend to leach out due to humidity or moisture. The product will only leach as a result of an abundance of running water.

Coating

Many commercial coating products are available to provide varying degrees of protection to wood against fire. These coatings generally have low surface flammability characteristics and “Intumesce” to form an expanded low density film upon exposure to fire. This film insulates the wood surface below from high temperatures. Also, coatings have ingredients that restrict the flaming of any released combustible vapors. These formulations may contain chemicals that promote the rapid decomposition of the wood surface to charcoal and water rather than forming intermediate volatile flammable products.

IGNITION: Almost all fires start from a small flame source; even explosions generally are caused by a spark or other small flame. Ignition has occurred when a fire is able to sustain itself for any period of time. Statistics indicate that the vast majority of all fires are generated from the uncontrolled rise in temperature of a small heat source. At the early stage of a fire. The ignition phase, is most critical, for once ignition has occurred, the fire will be able to continue its growth only if it can feed on nearby flammable materials. By raising the temperature at which a material will ignite or support combustion, you have effectively reduced the material’s flammability. Natural fiber materials treated with Nochar’s fire retardant have a much higher ignition or combustion temperature. For example, wood normally combusts at 523 degrees Fahrenheit. However when treated with “NFP”, the combustion temperature has been raised to well over 1,000 degrees Fahrenheit (There is a direct correlation between surface and mass. Two pounds of thinly sliced wood veneer has a much lower combustion temperature and faster flame spread rate than the same wood in a 2 pound block. The more mass there is the more temperature is diffused throughout the wood, thus naturally slowing down the phenomenon of ignition.) The actual combustion or ignition temperature of materials treated with “NFP” depends on the amount of solids absorbed by the treated material. For example, wood treated with a surface spray or dampening will have a lower ignition temperature than wood treated by a vacuum process, pressure treatment or other newly developed methods. This is demonstrated by the flame spread rating difference in an E-84 Tunnel Test. Class A vs. Class C.

RADIATION: Once ignition has taken place in a material, it begins to produce heat energy on its own, or BTU output, which is radiated in all directions. The radiated heat of energy begins to raise the temperature of everything around the original flame.

• Radiation or heat flux is the focal point of much fire research being conducted today. Each type of material used produces a different amount of radiant heat or rate of heat flux. For example, normally speaking, synthetic material will produce twice the amount of radiant heat as a natural fiber. By calculating the amount of heat flux or watts of energy generated by various materials in a room, called the fuel load, adequate sprinkler systems can be designed producing the needed amount and flow rate of suppression liquids. The speed and direction of the fire growth can also be predicted.

Radiant heat given off by burning material heats the air around the flames causing the air to rise toward the ceiling of the room taking with it any byproducts of incomplete combustion, such as smoke and gasses. Heat, smoke and gasses begin to build from the ceiling down within seconds of the first flicker of flame in a typically furnished room.

FLAME SPREAD: Flame spread occurs as a result of the temperatures of materials surrounding the initial ignition flame, reaching combustion level as a result of radiated heat. The speed of this phenomenon increases in direct relationship to the size of the flame and the amount of surface involved in combustion. The larger the flame, the greater the amount of heat radiated and the faster the flame spread. Natural fiber materials treated with a Nochar fire retardant and tested in the E-84 Tunnel Test indicates a drastic reduction in flame spread through the control of radiant heat. For Example, a 5\8″, spruce-faced plywood has a normal flame spread of between (140) and (170). When treated with “NFP” in a spray-on treatment, the flame spread is reduced to below (75), or 50% going from a Class C to a Class B. The same plywood treated by either vacuum or other newly developed methods has a flame spread value of less than (25) or a Class A.

CONVECTION: The spiraling or circulatory movement of air. The heated air caused by radiation starts the heated air rising toward the ceiling where it is deflected by air current constantly rising from the heat source. As the heated air travels across the room it begins to cool down and sink toward the floor as more heated air is pushed upward, always carrying with it the hydrocarbons and by-products of the incomplete combustion (smoke). As the volume of moving air increases and builds speed the temperature begins to rise even faster. A soft yellow flame has a temperature of approximately 560 degrees Fahrenheit: however, when this flame is fanned by air current, the temperature begins to take a quantum leap and will almost instantly reach 1,600 degrees to 1,800 degrees Fahrenheit in a room.

FLASHOVER: Flashover occurs when the temperature is sufficient to cause all of the available combustible surfaces and the by-products of incomplete combustion to ignite spontaneously and simultaneously. When the heat and the expansion of gases become more than the room can contain, flashover occurs. Flashover usually causes windows to shatter and doors to he blown off their hinges. Nothing survives flashover.

Flashover occurs in approximately two minutes after the first flicker of flames. Flashover occurs as a result of decorative materials and furnishings acting as a fuel load and accelerant. Rarely does flashover involve structural assemblies until the resultant heat and combustion caused by flashover consume the membrane of a wall sufficiently to penetrate a wall cavity or penetrate the roof support plenum.

Introduction

Reference: UBC Sec. 17, BOCA Sec. 400406, NFPA 220 (or 101

A-6-2.1)

There are other key issues to be considered in construction or assembly. These issues center around the longevity or structural integrity during a fire. Even though certain building materials and assemblies may be considered noncombustible, their fire performance leaves a lot to be desired. This is due to structural strength loss when exposed to high temperatures, warping, and/or heat conductivity. Some materials crumble when exposed to high temperatures while others warp, sag and melt. All assemblies should be tested in the E-119 standard time and temperature curve test chamber for their longevity in a fire. Fire safety is an important concern in all types of construction. Information on the fire safe use of wood in construction is covered in this chapter. This includes fire performance characteristics, such as ignition, charring, flame spread, heat release, and smoke. When evaluating fire safety, basic data are needed on performance characteristics of building materials. Even more important than the performance of these materials is the design of the building. Therefore, methods are discussed for improving fire safety through design and fire retardant treatments that can improve the fire performance of wood. Major building codes generally recognize five classifications of construction based on types of materials and required fire resistance ratings. Of the five, wood is permitted in three of the classifications. These three types of construction have traditionally been referred to as heavy timber, ordinary, and light frame. Heavy timber construction has wood columns, floors, roofs and interior partitions of certain minimum dimensions. For example, beams and girders may be not less than nominal (6) inches in width and not less than nominal (10) inches in depth. Ordinary construction has smaller size wood members, such as nominal (2) inch thick wood joists. In both heavy timber and ordinary construction, the exterior walls are of noncombustible materials. In light frame construction, the walls, floors, and roofs may be nominal (2) inch thick wood framing and the exterior walls may be of combustible materials. The fire resistance of light frame and heavy timber construction will be discussed later.  While the other two classifications, fire-resistive and noncombustible constructions, basically restrict the construction to noncombustible materials’ fire retardant treated wood is permitted in limited applications.

The option to approve alternatives is provided by the following codes: BOCA Sec. 107;

UBC Sec. 105; NFPA 101 Sec. 1-5

The high level of national concern for fire safety is reflected in limitations and design requirements in the building codes. The codes provide the minimum statutory requirements for fire safety. Adherence to codes will result in an improved level of fire safety. Code officials should be consulted early in the design of a building, because the codes offer alternatives. For example, floor areas can be increased with the addition of automatic sprinkler systems. Code officials have the option to connects with the wall; (2) fire-stops at each floor level in partitions that are continuous through two or more stories: (3) fire-stops at all interconnections between concealed vertical and horizontal spaces such as occur at soffits, drop ceilings, and cove ceilings; (4) headers at the top and bottom of the space between stair carriages; (5) mineral wool or equivalent noncombustible material packed tightly around pipes or ducts that pass through a floor or a fire-stop; and (6) self-closing doors on vertical shafts such as clothes chutes.

Figure 2 Draft-stops in multifamily buildings. Top, in floor/ceiling assemblies and bottom, in attics, mansards, overhang, or other concealed roof space above and in line with tenant separation when tenant separation walls do not extend to the roof sheathing above ;( NFPA).

Draft-stops are barriers in large concealed passages. New design and construction techniques such as suspended   or  dropped  ceilings  and  parallel  chord  trusses  have  resulted  in  new  draft-stop requirements.  Draft stopping materials include 1/2 inch gypsum board and 3/8 inch plywood. Two locations where draft-stops should be used to break up a large area are floor-ceiling assemblies in which the ceilings are either suspended below solid wood.  Joists and/or open-web trusses and attics and other concealed roof spaces such as mansards and overhangs. Some construction practices increase the risk of a fire spreading to the concealed spaces. Installing cabinets shower stalls and other structures without an interior wall lining on the studs allow easier penetration into the wall cavities.  A built-in bathtub provides interconnections between two walls and the floor. A thin plywood cover over a trapdoor allows a fire to spread easily to the attic or other concealed spaces.