Fire Inspection and Code Enforcement, 7th Edition

Chapter 6 — Building Construction:

Components

Inspector II

Inspector II 6–1

Inspector II

Today we will…

Discuss fire walls, party walls, fire partitions, and curtain walls

Discuss roof types and coverings

Discuss various characteristics of floors

Inspector II 6–2

Inspector II

Today we will…

Describe common characteristics of ceilings.

Describe types of stairs and their common components and explain how stairs are protected when used as part of the means of egress.

Purpose of Fire Walls

• Erected to limit maximum spread of fire

• Act as an absolute barrier to a fire under conditions of a total burnout on either side

• Fire-resistance ratings

Inspector II 6–3

Fire Wall Construction Types

• Freestanding

– Self-supporting and independent of building frame

– Found in buildings of wood-frame or masonry construction

• Tied

– Erected at a column line in a building of steel-frame or concrete-frame construction

Inspector II

6–4

Fire Wall

Inspector II 6–5

Characteristics of Fire Walls

• Must extend beyond walls and roofs to prevent radiant heat of flames from igniting adjacent surfaces

• Subdivide a building into smaller areas so that a fire in one portion of a building is limited to that area and does not destroy entire building

Inspector II 6–6

(Continued)

Characteristics of Fire Walls

Inspector II 6–7

Fire Wall Openings

• Must be protected by automatic or self-closing fire doors

• When ducts for heating, ventilating, and air-conditioning (HVAC) systems penetrate fire walls with a fire-resistance rating of 2 hours or more, ducts must be equipped with fire and smoke dampers.

Inspector II 6–8

Party Wall

• Lies on a lot line between two buildings and is common to both buildings

• Erected to limit maximum spread of fire

• Frequently function as fire walls and extend through a building from the basement through the roof, capped with a parapet

Inspector II 6–9

Fire Partitions and Fire Barriers

• Interior walls used to subdivide a floor or area of a building

• Do not qualify as fire walls

• Fire Partitions

• Fire Barriers

Inspector II 6–10

(Continued)

Fire Partitions and Fire Barriers

• Can be constructed from wide variety of materials

• When floor area of a building is subdivided with fire-resistive partitions/walls, it is compartmentalized

Inspector II 6–11

Enclosure and Shaft Walls

• Used to encompass vertical openings that extend from floor to floor in a building

• Purpose

• Requirements

Inspector II 6–12

Curtain Wall

• Exists when a building is constructed using a structural frame for its main structural support

• Separates interior environment from exterior

Inspector II 6–13

(Continued)

Curtain Wall

Inspector II 6–14

(Continued)

Curtain Wall

• Construction

• Must be constructed to resist:

– Wind

– Rain

– Snow

Inspector II 6–15

(Continued)

Curtain Wall

• Must control

– Heat loss

– Noise transmission

– Solar radiation

• Lacks inherent fire resistance

Inspector II

6–16

(Continued)

Movable Partitions

• Make it possible to subdivide interior of a building to suit different needs

Inspector II 6–17

Roofs

• Fundamental part of all buildings

• Primary function — Provide protection from weather

• Can contribute to fire hazard of a building

Inspector II 6–18

Roof Types

Inspector II 6–19

Trusses

• Framed structural units made of a group of triangles in one plane

• Vulnerable to early failure under fire conditions due to reduced mass of components and interdependence of those components

Inspector II 6–20

Roof Coverings

• Provide water-resistant barrier for roof system

• Type used depends on a number of factors

• Wood roof shingles and shakes

Inspector II 6–21

(Continued)

Roof Coverings

• Asphalt shingles

• Clay, slate, and cement tiles

• Metal roof coverings

Inspector II 6–22

(Continued)

Floor Construction

• Concrete

• Terrazzo

• Clay tiles

Inspector II 6–23

(Continued)

Floor Construction

• Wood

• Brick

Inspector II 6–24

(Continued)

Floor Supports

• Steel

• Wood

• Masonry

Inspector II 6–25

Floor Coverings

• Carpet

• Paint

• Laminated wood

• Vinyl

• Ceramic tile

Inspector II 6–26

(Continued)

Floor Coverings

• Can conceal actual floor system beneath

• Flammability

– Can be increased by floor coverings

– Codes limit flammability of floor coverings

Inspector II 6–27

Floor Penetrations and Openings

• Must include fire-resistive enclosures

• Types of openings

• Ideally, should be enclosed

• Unprotected opening

Inspector II 6–28

Ceilings

• Do not play a structural role

• Frequently have a functional role in building

• Interstitial space can be used as a return-air plenum; fire inspector must ensure that materials are noncombustible or rated for plenum use

Inspector II 6–29

(Continued)

Types of Stairs

• Protected or enclosed stairs

– Part of required means of egress; must provide protection for occupants as they travel to safety

• Access or convenience stairs

– Not required to be a part of means of egress system and typically connect no more than two levels

Inspector II

6–30

Stair Designs

Inspector II 6–31

Stair Components

Inspector II 6–32

Stairs

• Can serve as chimneys to spread smoke and fire

• Provide a means of escape from all levels of the structure

Inspector II 6–33

DISCUSSION QUESTION

Why is it important that stairs meant for use as escape routes be as smoke free as possible?

Inspector II 6–34

Protected Stairs

• Enclosed with fire-rated construction depending on building height

• Generally serve two or more stories and part of the required means of egress

• Stair enclosures

Inspector II 6–35

(Continued)

Protected Stairs

Inspector II 6–36

Exterior Stairs

• Open to air

• Generally protected by limiting or protecting opening in building’s outside wall near stairs

• Enclosed

Inspector II 6–37

Fire Escapes

• Open metal stairs and landings attached to outside of a building

• Not permitted in new construction

• May not be able to support required live load created during emergency evacuations or fire suppression operations

Inspector II 6–38

(Continued)

Fire Escapes

Inspector II 6–39

Smokeproof Stair Enclosures

• Required by building codes under certain circumstances

• Stair enclosures using either active or passive smoke control

• Mechanical ventilation system

Inspector II 6–40

Unprotected Stairs

• Not protected from fire and smoke in building they serve

• Not enclosed with fire-rated construction

• Allowed in buildings when connecting only two adjacent floors above basement level

Inspector II 6–41

(Continued)

Unprotected Stairs

• Can be used as part of an exit system in a two-story building

• Open stairs — Only allowed in building equipped with an automatic sprinkler system in particular occupancies

Inspector II 6–42

Inspector II 6–43

Summary

• Many components are incorporated into a building’s structural system, as well as a number of systems that enclose the structural components to define a building’s limits.

(Continued)

Summary

• Certain components provide access to structures, and others are finished with interior finishes, all of which may or may not contribute to fire spread.

Inspector II 6–44

(Continued)

Summary

• Building services may also increase or decrease inherent fire hazards within a building.

• An inspector must be able to evaluate these building components and determine the level of fire protection provided by them.

Inspector II 6–45