481

Section

Fireproofing

Contents

7

7.0.0 Fireproofing or fire resisting?7.1.0 Four accepted methods to fireproof

steel7.1.1 Spray-on or trowel-on “dry” or “wet”

systems7.2.0 Fireproofing terminology7.3.0 Typical spray fireproofing specifica-

tions7.4.0 Spray fireproofing guide for dry mix

applications7.5.0 UL/ULC fire-resistance ratings chart

(dry and wet mixes)7.6.0 Standard physical-performance prop-

erties for spray-applied materials7.7.0 Column fireproofing utilizing gyp-

sum drywall (two- and three-hourratings)

7.8.0 Two-hour fire-rated drywall columnenclosure (UL Design X518)

7.9.0 Two three-hour drywall column en-closure design (UL Design X518,X515)

7.10.0 Three-hour drywall column enclo-sure at precast concrete panel (ULDesign U904)

7.11.0 Three-hour drywall column enclo-sure at 12" block wall corner (ULDesign X515)

7.12.0 Three-hour concrete column enclo-sure (traffic area)

7.13.0 Three-hour masonry column enclo-sure

7.14.0 Fire resistant materials and con-struction per the Uniform BuildingCode

7.15.0 Finishes on interior surfaces perUniform Building Code

7.16.0 Flame spread classifications7.17.0 Maximum flame spread classifica-

tions7.18.0 Firestopping through-penetrations

7.0.0 Fireproofing or Fire Resisting?

Fireproofing, in many cases, might better be referred to as fire resistance because the materials ap-plied, mainly to structural steel systems, are meant to protect these systems from collapsing whenexposed to the presence of fire for specific periods of time (one, two, three, or four hours). In othercases, the term fire retardant is more applicable, particularly when applied to flammable or com-bustible materials, like wood. In this case, fire retardancy provides a limit to the flame spread, fuelcontribution, and smoke development that would have occurred if the combustible surface had notbeen treated with a fire-resistive coating.

7.1.0 Four Accepted Methods to Fireproof Steel

1. Spray or trowel on materials of a cementitious or mineral-fiber nature.

2. Concrete encase structural steel columns or beams, or increase the thickness of concrete-suspended slabs on metal deck.

3. Apply specific numbers of layers of gypsum drywall onto the structural steel members.

4. Spray, brush, or roll on a water- or solvent-based intumescent material or mastic.

7.1.1 Spray-on or Trowel-On “Dry” or “Wet” Systems

Spray- or trowel-on “dry” or “wet” cementitious or mineral-fiber materials are the most prevalentforms of structural-steel fireproofing and are generally divided into two groupings (Type I and Type II).

• Type I A factory-mixed cementitious materials with a minimum density of 15/14 pounds per cu-bic foot (240 kg/cubic meter).

• Type II A factory-mixed, asbestos-free, mineral-fiber material with inorganic binders, having aminimum applied dry density of 15 pounds per cubic foot (240 kg/cubic meter). If this system isused, it is generally followed by a water overspray to press any loose fibers and allow the bindersto migrate and product a firm surface.

7.2.0 Fireproofing Terminology

• Air erosion Resistance of spray fireproofing to dusting, flaking, sifting, and delamination be-cause of air movement across its surface. ASTM E-859-82/GSA sets the performance quality for airerosion; it is to be 0.025 gm/ft2 maximum.

• Bond strength The ability of the spray fireproofing to resist pulling away from the steel sub-strate. The higher the bond strength, the lower the chance for cohesive or adhesive failure. ASMTE-736-80 refers to bond strength and sets 200 lbs/ft2 as the minimum bond strength.

• Damageability The resistance to physical abuse from abrasion, impact penetration, and com-pression. Two tests conducted by the City of San Francisco developed two standards and one testby ASTM provides the third:

Impact penetration Six cubic centimeters maximum (City of San Francisco).

Abrasion resistance 22 cubic centimeters maximum (City of San Francisco).

Compression 500 pounds per square foot minimum (ASTM E-761-80).

• Dry mix It has no requirement to pre-mix with water or other additives. It can be applied in itsoriginal state by air under pressure. Water is introduced at the spray nozzle prior to application.The dry mix is quick and easy to apply.

• Wet mix The product is mixed with water to provide a slurry that is applied under high pressurethrough a nozzle. Although it is frequently referred to as cementitious, many manufacturer’sproducts do not contain cement. This type of application provides cost-effective, fire-resistant per-formance per unit thickness.

482 Section 7

7.3.0 Typical Spray Fireproofing Specifications

Fireproofing 483

7.4.0 Spray Fireproofing Guide for Dry Mix Applications

484 Section 7

(By permission of Isolatex International, Stanhope, New Jersey.)

7.4.0 Spray Fireproofing Guide for Dry Mix Applications—Continued

Fireproofing 485

(By permission of Isolatex International, Stanhope, New Jersey.)

7.5.0 UL/ULC Fire-Resistance Ratings Chart (Dry and Wet Mixes)

486 Section 7

(By permission of Isolatex International, Stanhope, New Jersey.)

7.6.0 Standard Physical-Performance Properties for Spray-Applied Materials

Fireproofing 487

(By permission of Isolatex International, Stanhope, New Jersey.)

7.7.0 Column Fireproofing Utilizing Gypsum Drywall (Two- and Three-Hour Ratings)

488 Section 7

(By permission from United States Gypsum

Corp., Chicago, Illinois.)

7.8.0 Two-Hour Fire-Rated Drywall Column Enclosure (UL Design X518)

Fireproofing 489

7.9.0 Two Three-Hour Drywall Column Enclosure Design (UL Design X518, X515)

490 Section 7

7.10.0 Three-Hour Drywall Column Enclosure to Precast Concrete Panel (UL Design U904)

Fireproofing 491

7.11.0 Three-Hour Drywall Column Enclosure at 12" Block Wall Corner (UL Design X515)

492 Section 7

7.12.0 Three-Hour Concrete Column Enclosure (Traffic Area)

Fireproofing 493

7.13.0 Three-Hour Masonry Column Enclosure

494 Section 7

Fireproofing 495

(Reproduced from the 1997 Edition of the Uniform Building Code, Volumes 1, 2, 3, copyright 1997, with the permission of the

publisher, the International Conference of Building Officials (ICBO). ICBO assumes no responsibility for the accuracy or the

completion of summaries provided therein.)

7.14.0 Fire Resistant Materials and Construction per Uniform Building Code

496 Section 7

Continued

Fireproofing 497

Continued

498 Section 7

Continued

Fireproofing 499

Continued

500 Section 7

Continued

Fireproofing 501

Continued

502 Section 7

Continued

Fireproofing 503

(Reproduced from the 1997 Edition of the Uniform Building Code, Volumes 1, 2, 3, copyright 1997, with the permission of the

publisher, the International Conference of Building Officials (ICBO). ICBO assumes no responsibility for the accuracy or the com-

pletion of summaries provided therein.)

7.15.0 Interior Finish Criteria

504 Section 7

Figure 7.15.0—Continued

(Reproduced from the 1997 Edition of the Uniform Building Code, Volumes 1, 2, 3,

copyright 1997, with the permission of the publisher, the International Conference of

Building Officials (ICBO). ICBO assumes no responsibility for the accuracy or the com-

pletion of summaries provided therein.)

(Reproduced from the 1997 Edition of the Uniform Building Code, Volumes 1, 2, 3, copyright 1997, with the permission of the

publisher, the International Conference of Building Officials (ICBO). ICBO assumes no responsibility for the accuracy or the com-

pletion of summaries provided therein.)

7.16.0 Flame Spread Classifications

7.17.0 Maximum Flame Spread Class

Fireproofing 505

7.18.0 Firestopping Through-Penetrations