BUILDING CONSTRUCTION IFSTA : Chapter 3

BUILDING CONSTRUCTION IFSTA : Chapter 3 Additional reading: IFSTA Essentials #4 – chapter 8, 9, 10 Only for the information relating to building construction Some quiz, midterm and final questions will be from this material

Learning Objectives List and define five types of building construction. Identify the effects fire has on common building materials to enable firefighter’s to effectively attack the fire. Identify the different occupancies and their effects at a structure fire.

Learning Objectives Identify the hazards of building construction during fire suppression operations. Identify construction features during size up. Identify indicators of structural failure or collapse during fire suppression operations

Types of Building Construction Most building codes have 5 types of building construction. Many buildings include several types of construction.

Type I: Fire Resistive Construction Structural members made of noncombustible / limited combustible materials. Construction intended to confine fire and its byproducts to a given location. Primary fire hazard is contents of structure.

Type II: Noncombustible Construction Lower degree of fire resistance than type I. Fire resistance rating on all exterior and interior load bearing walls. May have combustible features, as materials with no fire resistance rating may be used. Generally have flat roofs with combustible felt, insulation and roofing tar.

Why is Size-up Important?

Type III: Ordinary Construction Exterior walls & structural members of noncombustible / limited combustible materials. Interior members (walls, beams, floors, roof) are made of wood. Hazards: smoke and fire spread through concealed spaces. Fire stops to limit spread.

Type IV: Heavy Timber Exterior / interior walls noncombustible material. Interior structural members (beams, columns, arches, floors etc.) made of solid or laminated wood with no concealed spaces. Found in old factories, warehouses, churches.

Type V: Frame Construction

Type V: Frame Construction Exterior and interior structural members made of wood. Fire Hazards: unlimited potential for fire extension, fire extension to nearby structures. Typical residential home MOST COMMONLY DEALT WITH CONSTRUCTION TYPE.

Platform Frame

“Silent Flooring”

Poor Construction Methods

Fire Effects on Common Construction Materials – Wood May be used in load bearing and non-load bearing walls. Reaction of wood to fire conditions is based on the size of the wood and its moisture content. Water does not have a negative effect on wood’s structural strength. Plywood, particle board, paneling may be highly combustible, produce toxic gases and rapidly deteriorate under fire conditions.

Fire Effects on Common Construction Materials - Masonry Brick, concrete, and stonework. Commonly used for firewalls to separate connected structures and prevent fire spread. May be used as load bearing or veneer. Minimally affected by fire & high temperatures. Mortar joints between bricks, blocks may deteriorate. (mortar mix is weakest part of wall) Rapid cooling of masonry by water may cause cracking or spalling.

Fire Effects on Common Construction Materials - Concrete Concrete is a mixture of portland cement, sand, gravel and water. Often used as a fire resistive protection for structural steel (reinforced concrete). May crack or spall if heated, indication of damage & reduced strength. Heating may cause bond between steel and concrete to fail. Concrete tends to absorb and retain heat.

Fire Effects on Common Construction Materials – Reinforced Concrete

Fire Effects on Common Construction Materials - Steel Primary use of steel is for structural members. Steel is an excellent conductor of heat. Steel loses strength as temperature increases Steel structural members will elongate when heated. Water can cool steel structural members and reduce risk of failure or collapse.

Fire Effects on Common Construction Materials - Steel

Fire Effects on Common Construction Materials - Plastic Becoming integrated to replace/improve common building materials Plastics are oil-based (hydrocarbons) Two general types Thermoplastics (melt, deform, vapourize = burns!) Thermosets (decomposes, only burns with extreme temps)

Fire Effects on Common Construction Materials - Plastic General Rule of Thumb when fighting fires involving plastics… Burn fast Very intense heat Dense black smoke Extremely toxic Can resemble a Class B Fire (flammable liquids)

BREAK TIME

Roof Types Three Main Types: (a) Flat (b) Pitched (c) Arched

Occupancy Versus Type of Construction Occupancy creates the fire load. Building codes specify building type based on occupancy classification. Fire code determines fire protection based on building and occupancy use. Occupancies are residential, commercial, business, industrial and educational. Each type has a number of hazards.

Occupancy Hazards

Building Uses Ontario Fire Code and Ontario Building Code separate buildings in groups A-F, as related to their major use (or major occupancy) With each type of building comes various requirements/restrictions on building construction Private dwelling residences are exempt (with some exceptions)

Building Uses A – Assembly B – Institutional (compelled to sleep over) Theatres, libraries, schools, large bars, pubs and restaurants B – Institutional (compelled to sleep over) Jails, hospitals, orphanages, nursing homes C – Residential Apartment buildings (common area) , group homes, houses, motels D – Business and Personal Services Banks, barber shops, offices (medico legal), laundromat E – Mercantile Markets, stores, shops, supermarkets, restaurants, bars and pubs F – Industrial Flammable liquid plant, television studio, freight depot

Firefighter Hazards: Structure Fires Change in occupancy creating an unusually heavy fire load. Dangerous stockpiling and excessive stock creating access problems. Unknown design errors, renovations, contractor short cuts. Arsonists traps or tampering with fire protection systems. Occupancy may not be what it appears. (drug lab, boarding house, group home, etc.) ALL OF THESE TYPES OF CONDITIONS WILL CONTRIBUTE TO FIRE SPREAD.

Construction Features Assessed During Size Up What constructions features are important during size-up?

Construction Features Assessed During Size Up

Firefighter Hazards: Structure Fires Combustible furnishings & finishes. Wooden floors / ceilings. Large open spaces. Synthetic materials. Lightweight & truss construction.

Lightweight Wood or Steel Truss Construction = Very Dangerous Firefighting Conditions

Truss Roofs

Bowstring Truss!

Beware of the Truss!

Structural Collapse Every structure fire has the potential for collapse. Firefighters must be aware and look for indicators to collapse.

Signs of Potential Collapse Prolonged exposure.(time) Distorted structural members. Fire on floors below heavy machinery and heavy loads.

Signs of Potential Collapse

Building Collapse Zone

Size Up – What do you see?

The Back?

The Side?

Summary Firefighters must know & understand building construction. There are five common types of construction. Firefighters need to be aware of the hazards associated with structure fires. Effects of fire on building materials. Signs of structural collapse.