Wood

Masonry

Concrete

Steel

• Aluminum
• Cast iron
• Copper
• Zinc

Metals

Glass

Gypsum board

Plastics

Fabric

Combustibility

Thermal conductivity

• As temperature increases, materials weaken and strength is compromised

Variation of strength with temperature

• Chemical and physical properties
• Method of fabrication

Behavior of building materials affected by

• Assigned to an opening in a fire wall
• Indicates the length of time a protective assembly (door, window) can withstand fire conditions
• May use a lower rating than the surrounding fire-resistant barriers
• Assumed that the fire load will not be close to assemblies

Fire protection rating

• Wall assemblies
• Rated through laboratory testing to determine ability to withstand fire conditions over a set amount of time

Fire-resistant materials

• Applied to the surface of combustible materials
• Suppress, reduce, or delay the flame-spread rating
• Behave in unique ways

Fire-retardant coatings

• Materials used to decrease the vulnerability of structures
• Features include fire-resistance roof coverings

Ignition-resistant construction

Buildings constructed of wood can be destroyed by fire

Voids result in many square feet (square meters) of combustible surface area surrounded by large volumes of air

Different properties of wood affect its use in construction

Strength of wood varies significantly, the IBC® requires lumber be graded (labeled) to denote its strength

Primarily used in construction as solid lumber and as engineered wood products

Standard measurements of dimensional lumber match the stated measurements

Dimensional lumber is available in lengths from 8 to 24 feet (2.5 to 7 m) in 2-foot (600 mm) increments

Dimensional lumber

Panels

Adhesives

Metal fasteners

Trusses

Box beams

I-beams

Panel components

Beams produced are called glued-laminated beams

Advantage: sizes and shapes not available in solid wood like curves and varying cross-sections

Provide additional surface area for the glue

Allow the transmission of a greater amount of force than a typical butt joint

Inspectors need to know that these joints hold laminated members together

Possess several advantages from a construction standpoint

Widely used for roofs, subflooring, and siding

Panel products are more equal in strength along their two major axes

Graded for their structural use and their exposure durability

Grade stamp on the back indicates its intended application and suitability for exposure to water

Stressed skin panels consist of an interior frame or plastic foam core

A skin of plywood or OSB is attached to the core

Commonly used in modular buildings

OSB used in roof decks, walls, and subfloors

Wood can be chemically altered with a fire retardant to reduce its susceptibility to ignition

Building codes permit the use of fire-retardant-treated wood for certain applications

Should not be confused with materials that are noncombustible or fire resistive

Two main methods of fire-retardant treatment of wood include pressure impregnation and surface coating

Only these treatments can produce wood that is listed as fire-retardant-treated wood

The most commonly used fire-retardant treatments are combinations of inorganic or organic salts

Surface coating is used primarily to reduce the surface burning and flame spread characteristics of wood

Fire-retardant chemicals used in the pressurization process are proprietary products

• Some treatments use chemicals that are water soluble, prohibiting their use for exterior applications
• Others can be used in interior applications where high humidity does not exist
• May adversely affect the structural strength of wood as a result of elevated temperature and humidity

Regarding water solubility and structural strength

• Coatings are often painted over or not maintained
• Look for missing coating

Intumescent coatings can be applied to wood to make its surface fire-resistant

Provide resistance to environmental and pest infiltration

Sidings are often chosen for aesthetic reasons; underlayers chosen for compatibility with sidings

• Installed outside the studs to provide structural stability, insulation, and an underlayer for the siding
• Most common are plywood, OSB, particle board, or exterior gypsum sheathing

Sheathing

• Put between the sheathing and the siding; acts as a vapor barrier
• Reduces the infiltration of moisture and air
• Modern synthetic wraps are much more fire-resistant than the felt or tar paper used in older installations

Building wrap

Combustible insulation does somewhat increase the possibility of a fire starting within the wall

• Air space will contribute to rapid fire development within the wall space
• However, if the space is completely filled, the fire has to burn upward through the material and will progress much more slowly

Extent to which foam insulation will increase fire spread within a wood-framed wall depends on the existence of air space

Glass wool and rock wool in the form of batts or blankets with combustible paper or foil coverings

Fiberglass

• Granulated rock wool
• Mineral wool/glass wool blown into or manually packed into studs
• Cellulose fiber/shredded wood treated with water-soluble salts to reduce combustibility

Loose-fill

• Soft foam insulation that hardens after application
• Foam is treated with flame retardants before application
• Style of insulation is gaining popularity and is referred to as “building icing” because of its appearance
• Two types: polyurethane foam and urea formaldehyde foam

Solid-fill

Provides weather protection

Can contribute to the appearance of a building

Some materials are noncombustible

Some materials are combustible

Combustibility of a siding material can affect fire behavior

New siding is frequently applied over existing siding

Aluminum

Asphalt siding/shingles

Cement board

Plywood

Stone

Stucco

Wood boards

Wood shingles

Vinyl

One of the oldest and simplest building materials

Can be used for fencing or stone work trim

• Fundamental construction technique consists of stacking masonry units on top of one another and bonding them into a solid mass

Inspector’s chief interest is masonry’s use for wall construction

• Masonry units are inherently fire-resistive, however, mortar joints may deteriorate over time or when exposed to fire and result in weakening of the structure

Masonry caution

Brick

Concrete block

Stone

Clay tile block

Gypsum block

Produced from a variety of locally available clay and shale

Manufactured by placing clay in molds, removing the molded clay, and drying

Fired in a kiln during which they are subjected to temperatures as high as 2,400°F (1 300°C)

Intense heat converts them to a ceramic material

Also known as concrete masonry units (CMUs)

Most commonly used concrete block is the hollow concrete block, sometimes referred to as cinder block

In addition to the hollow block, concrete masonry units can be produced as either bricks or as solid blocks

Consists of pieces of rock that have been removed from a quarry and cut to the size and shape desired

Principal types: granite, limestone, sandstone, slate, marble

Used in two ways: laid with mortar to form walls or used as an exterior veneer attached by supports to the structural frame

Used for foundations and walls in areas where clay is available

Blocks are hollow, providing a space for fill material

Blocks do deteriorate over time

Blocks are susceptible to damage from water and freezing temperatures

Gypsum block is not used often in modern practice

Were once widely used for construction of interior partitions

Structural glazed tile is still frequently used

Pavement

Foundations

Columns

Floors

Walls

Concrete masonry units

Does not burn

Resists insects

Resists the effects of contact with soil

Can be placed in forms to create a variety of architectural shapes

Concrete types include ordinary and lightweight

Cannot be used alone where significant tensile forces occur in a structure

Concrete is reinforced through the use of steel bars (rebar) or cables placed within the concrete

Basically an alloy of iron and carbon

Common structural steel has less than three tenths of one percent carbon

Strongest of the structural materials

Nonrotting

Resistant to aging

Dimensionally stable

Flame resistant

Relatively expensive

Strength and the variety of forms in which it is produced allow it to be used in smaller quantities than other materials

Used for applications varying from heavy beams and columns to door frames and nails

• Tends to rust when exposed to air and moisture
• Loses strength and elongates when exposed to the heat of a fire; can cause exterior walls to fail and eventually lead to building collapse
• Rust can be an indication of deterioration or a weakening of the structure; especially exposed fire escapes

As a structural building material

• Painting the surface with a rust-inhibiting paint
• Coating it with zinc or aluminum
• Can be produced using ingredients that resist rust, as in the case of stainless steel

Methods employed to overcome

Mass of the steel members and surface area exposed

Intensity of the exposing fire

Load supported by the steel

Type of structural connections used to join the steel members

Most common method is through the use of an insulating material

Metal lath and plaster

Gypsum board

Sprayed-on cement coating

Mineral and fiberboard

More susceptible to being dislodged as well

Damage may reduce or negate the fire rating of the member

Damage needs repair whether it happens during construction or over time

Paint-like coatings

Applied in thicknesses of a fraction of an inch (millimeter)

Provide fire-resistance ratings of up to three hours when applied as required by its listing

Frequently used to protect steel floor support systems

Noncombustible ceiling system or a special insulating ceiling tile

Popular with designers

Allows ductwork and electrical conduit to be hidden above the ceiling

Provides an attractive finished surface

Rated ceiling acts as a thermal barrier to the heat of a fire below it

May require special provisions to maintain the integrity of the ceiling

Present in most buildings

Windows, skylights, storefronts, and anywhere light transmission is desirable

Architectural applications of glass include church windows, partition walls, and some structural applications

Be aware: when glazing is broken, it is often replaced with inferior glass

• Produced by slowly cooling the hot glass during its production; permits the release of thermal stresses that would form if the glass were cooled rapidly

Single-strength annealed

• Residual surface compression stronger than annealed glass of the same size and thickness; more resistant to thermally induced stresses, cyclic wind pressures, and impacts by windborne objects

Heat-strengthened

• Residual surface compression even stronger than heat-strengthened glass
• Breaks into small granules; used in windows that might be subject to high wind forces and exterior doors that people might walk into accidentally

Fully tempered

• Consists of two layers of glass with a transparent layer of vinyl bonded into the center
• When broken, the inner core of vinyl holds the broken pieces of glass in place; used in security windows and to reduce noise transmission

Laminated

• Produced either as solid or hollow non-load-bearing units
• Can have different surface patterns
• May be used for the protection of limited-size openings in fire-rated walls when permitted by the local building code

Glass block

• Used in both interior and exterior applications
• Used in fire doors, in windows adjacent to fire escapes, in corridor separations, and to protect against exterior exposures
• When glass breaks, the wires hold the glass in place, permitting it to act as a barrier to a fire

Wired glass

• Does not use interior wires
• Made from a combination of glass and plastic
• Must be installed in a fire-rated framing that is rated as an assembly

Fire-rated glass

Also known as drywall or Sheetrock®

Mineral-based product used to construct plaster and wallboards

High water content gives it excellent heat-resistant and fire-retardant properties

Corridor partitions

Stair enclosures

Shaft walls

Column protection

Membrane ceilings

• Used in fire-rated assemblies
• Produced with glass fibers that act as reinforcement and provide tensile strength; prevent its deterioration when exposed to fire

Type X

• Contains vermiculite that expands as it is exposed to heat; allows the gypsum to maintain its integrity and remain dimensionally stable for longer periods of exposure

Type C

Regular gypsum board

• Used for most applications

Water-resistant gypsum board

• Water-repellent paper facing for use where it may be exposed to moisture

Type X and Type C gypsum board

• Used in fire-rated assemblies

Foil-backed gypsum board

• Used to replace the vapor barrier in outside walls

Gypsum backing board

• Used as a backing layer in multilayer assemblies

Coreboard

• Used for shaft walls and solid partitions

Siding

Floor covering

Insulation

Tub/shower enclosures

Vapor barriers

Pipe and pipe fittings

Lighting fixtures

Skylights and roof domes

Sprinkler piping

Moldings

Wall coverings

Gratings and mantel pieces

Strength of plastic materials is close to that of wood

Glass-fiber-reinforced plastic may be nearly as strong as steel

Not usually used for structural applications in buildings because of their generally lower strength and their greater tendency to bend

Increases fire hazards, both inside and outside the structure

Some plastics used as thermal barriers may be invisible to the inspector once the structure is completed

Other plastics, used for external veneer, may be difficult to recognize

Flammability of plastics varies widely

Some plastics, such as cellulose nitrate, burn so rapidly that they constitute a unique fire hazard

Other plastics may burn slowly and stop burning when the ignition source is removed

Fire retardants can be added to some plastics to reduce their flammability and ignition sensitivity

Even plastics with low flammability are subject to deterioration and may give off toxic gases at temperatures above 500°F (260°C)

• Some materials drip
• Some plastics generate enormous quantities of heavy smoke

Plastic materials frequently exhibit burning properties different from other materials

Products of combustion of some plastics are more toxic than nonplastic materials

They add to the amount of fuel in a building

Increase the toxicity of products of combustion

• Requires special treatment like covering the surface of the insulation with a noncombustible material or installing automatic sprinklers

Where large amounts of plastic are used the fire hazard is greatly increased

Installed to reduce the heat rise of the material it is protecting

Adopted building codes may require the use to separate plastics and other combustible materials from the interior of the building

One application for plastic in an exterior veneer system

Consists of fiberglass insulation, gypsum board, expanded polystyrene beadboard , extruded foam with a noncombustible hand-troweled finish

Finished product closely resembles a stucco or etched-concrete finish

A way to improve the appearance of an existing masonry wall that has become deteriorated

EIFS can be ignited from exterior source or radiant heat of exposed fire

• Foam insulation is combustible
• Flame spreads rapidly over its surface
• Typically, a code will require that foam insulation be faced with a thermal barrier

Building codes impose stringent regulations on the use because