Fireproofing of Structural Steel and Equipment Supports

This article is about technical specification of Fireproofing of Structural Steel and Equipment Supports.

Table of Contents

1.	Purpose
2.	Scope
3.	Related Documents
4.	General
5.	Materials
6.	Installation
7.	Certification
8.	Fireproofing Details
Figure 1	Column Detail
Figure 2	Beam Detail
Figure 3	Column Cap Detail
Figure 4	Base Plate Detail
Figure 5	Vessel Skirt Without Insulation
Figure 6	Vessel Skirt With Insulation
Figure 7	Tank Saddle Detail

1. Purpose of This specification defines the fireproofing requirements for exterior structural steel and equipment supports.

2. SCOPE

2.1 This specification applies to exterior structural steel and equipment supports that are identified inCompany job specifications and engineering drawings as requiring a fireproofing system.

3. Related International Codes and Standards

American Society for Testing and Materials (ASTM)

ASTM E 84 Standard Test Method for Surface Burning Characteristics of Building Materials

ASTM E 605 Standard Test Methods for Thickness and Density of Sprayed Fire-Resistive Material (SFRM) Applied to Structural Members

ASTM E 1529 Standard Test Methods for Determining Effects of Large Hydrocarbon Pool Fires on Structural Members and Assemblies

Underwriters Laboratories Inc. (UL)

Fire Resistance Directory

UL 1709 Rapid Rise Fire Tests of Protection Materials for Structural Steel

4. Fireproofing of Structural Steel and Equipment Supports

The Contractor shall supply all labor, materials, and equipment to ensure a complete fireproofing system for all exterior structural steel and equipment supports as detailed in this specification and as outlined in the job specification or on the contract drawings. Top coating is not required for fireproofing covered by this specification.

5. Fireproofing Materials

5.1 Fireproofing

Acceptable fireproofing systems and their suppliers are as follows:

Pyrocrete®

241 Carboline Fireproofing Products Division

350 Hanley Industrial Court

St. Louis, MO 63144

Fendolite Mandoval Vermiculite Products, Inc.

3340 Bingle Road

Houston, TX 77055

5.2 Handling

Fireproofing shall be delivered to the job site in original, unopened, premeasured, factory-sealed packages. These material packages shall bear the name of the manufacturer, the brand name, and the proper UL labels for fire hazard and fire-resistance classification.
Any packages of fireproofing that are opened or exposed to water prior to use shall be discarded.
Fireproofing materials shall be stored in a dry area, above the ground, until they are ready for use.

5.3 Lath

Lath shall be 3.4 pounds per square yard, galvanized or primed metal lath, or other approved corrosion-resistive material.
Lath shall conform to the specifications of the listed and tested design as described in the UL Fire Resistance Directory (e.g., XR-704).

5.4 Anchoring Studs

Anchoring studs shall be of galvanized or primed metal or other approved corrosion-resistive material.
Anchoring studs shall conform to the specifications of the listed and tested design as described in the UL Fire Resistance Directory (e.g., XR-704).
Anchoring studs shall not be attached to any pressure vessel or to any tank.
Anchoring studs shall be either of these types:
1. Studs normally attached by electric welding techniques, such as those supplied by:
  - Midwest Fasteners, Inc.
  - 450 Richard Street
  - Miamisburg, OH 45342
  - TRW Nelson Stud Welding Division
  - 7900 West Ridge Road
  - Elyria, OH 44036
2. Self-drilling, self-tapping screws, such as those supplied by:
  - ITW Buildex
  - 1349-T West Bryn Mawr Avenue
  - Itasca, IL 60143
3. Self-adhesive pins shall not be used.

5.5 Water

The water used to mix the fireproofing material shall be fresh, suitable for domestic consumption, and free of mineral or organic substances that might affect the set of the fireproofing material.
Mixing water shall not contain more than 50 ppm of chlorides or sulfates.

5.6 Caulking

Acrylic, butyl rubber, or silicone caulking compounds that are compatible with cementitious material, or any materials that have an alkalinity of pH 12 or greater shall be used.

5.7 Primer

A primer might be required to recoat the steel prior to the application of the fireproofing material.
The primer shall be as recommended by the fireproofing material manufacturer, shall be suitable for application over the primer or finish paint used on the steel, and as indicated in the job specification or on the contract drawings.
The effectiveness of the primer and the compatibility of the primer with the existing primer paint shall be proven by the contractor by means of a sample application prior to the general application of the primer. (Refer to paragraph 6.3 for sample application details.)

5.8 Submittals

A material description of the fireproofing, lath, studs, caulking, and primer paint (when required) shall be submitted to Companyby the contractor. This description shall consist of the manufacturer’s published specifications, performance data, application instructions, Material Safety Data Sheets (MSDS) for each component, thickness required to meet the fire rating, and evidence of fire hazard classification by UL to conform to ASTM E 84. The fire rating shall be as defined by the appropriate design number tested by UL and listed in the UL Fire Resistance Directory.
The contractor shall submit to Companyfor approval, a certified laboratory report of a sample of the water to be used in mixing the fireproofing. This report shall indicate the amount of chlorides and sulfates in the water in parts per million (ppm). No fireproofing shall be mixed until Companyapproves the water sample laboratory report.
The contractor shall certify that all persons who are to apply the fireproofing materials have attended the required factory training program. The contractor shall submit copies of the material manufacturer’s certification of this training to Company .

5.9 Substitutions

Substitutions for materials specified in this specification shall be made only after written approval is obtained from Company .
Approval of a proposed substitution or alternate material will be granted by Companyonly when this material’s qualifications are supported by test data from UL. This data shall indicate that the proposed product is equivalent to the materials specified in this specification in chemical resistance, and in specified physical characteristics, as well as in fire resistance.
Materials such as sprayed mineral fiber, gypsum-vermiculite blends, foamed cementitious, magnesium oxychloride, and other friable materials that do not have physical characteristics equivalent to those of the material specified in this specification shall not be allowed.
Fireproofing material shall not contain any chlorides, sulfates, asbestos, or red label solvents.
Only nondusting products shall be used.
The fireproofing material shall form a hard, inorganic coating after curing. This coating shall resist abrasion, vibration, impacts, and similar forms of physical abuse under normal conditions.
Fireproofing material shall have been tested by UL in accordance with ASTM E 1529, UL 1709, and shall be listed in the UL Fire Resistance Directory.
Fireproofing material shall be suitable for exterior use without the need for application of paint or paint systems for weather protection.
Fireproofing material shall provide the fire endurance ratings indicated in the job specification or on the contract drawings for the steel on which they are applied.

6. Fireproofing of Structural Steel and Installation

6.1 General

All installation work shall be performed in strict accordance with the fireproofing material manufacturer’s latest dated application instructions.
Fireproofing shall be installed after all steel is in place.
Other trades shall be restricted from working on or adjacent to freshly applied fireproofing for a minimum of 24 hours after the fireproofing application has been completed.
Finished surfaces, in-place equipment, and piping shall be protected from damage and overspray or spattering by masking, covering, or other appropriate means.
Fireproofing shall be applied when temperatures are between 40°F and 100°F. The fireproofing manufacturer shall be consulted for further temperature guidelines when cold weather conditions exist.
Fireproofing shall be protected for a minimum of 24 hours after the application from severe weather, such as a heavy rainfall.
If rapid surface drying conditions are experienced, the fireproofing surface shall be wrapped with plastic or periodically wetted with a fine mist water spray until the material has cured.

6.2 Surface Preparation for Fireproofing of Structural Steel

Surfaces that are to have fireproofing applied to them shall be clean and in a condition that will enhance adhesion of the fireproofing. These surfaces shall be free of loose, foreign matter such as rust, scale, dust, grease, oil, release agents, and loose or flaking paint. These surfaces shall not have a glossy finish. Surfaces that are not clean and free of foreign matter or surfaces that will adversely affect fireproofing adhesion shall be reported to the Companyrepresentative. These conditions shall be corrected before the surfaces are covered with lath.
Beginning the fireproofing application shall indicate acceptance of surface conditions. The contractor shall be held accountable for unsatisfactory results.

6.3 Sample Application

The contractor shall prepare a sample application prior to proceeding with the work.
The sample application shall consist of a four-foot long specimen of fireproofing on a typical structural steel member that is already installed at the job site and that is identified as requiring fireproofing. The steel member shall be coated with the necessary primer (when required) prior to the application of the fireproofing. Fireproofing used in the sample application shall be mixed with water from the source that will be used to mix the remainder of the fireproofing.
The sample application shall be allowed to cure and shall then be inspected by an Companyrepresentative. The representative will approve satisfactory sample applications. The contractor shall be held accountable for unsatisfactory results if any fireproofing is applied without first obtaining this approval.
The sample application shall be used to:

- Prove the suitability of the fireproofing primer (when required) used with the paint system that was applied to the steel.
- Prove the suitability of the water used to mix fireproofing.
- Serve as a guide for any points of dispute related to workmanship and finish.

6.4 Lath

Lath shall be installed in accordance with the appropriate design in UL 1709 and with the details shown in Section 8. In addition, all columns having fireproofing shall have fire-stops installed on 8-feet centers. The fire-stops shall be made by bending lath inward from the hollow face of the box to the web of the column and covering the lath with the appropriate thickness of fireproofing.
Metal lath shall be installed overall on flat surfaces of cylindrical metal vessel skirts and tank saddles that are more than 12 inches wide. This lath shall be anchored on 12-inch centers using anchoring studs (refer to paragraph 5.4).

6.5 Fireproofing Application

Fireproofing shall be installed using a mortarboard and trowel technique on those areas and items listed in the job specification or on the contract drawings. Fireproofing shall be smoothed to an even texture, and all trowel marks shall be removed. All corners shall be square, and all edges shall be straight.
Approved open-mesh, galvanized corner beads may be used, when installed in accordance with the manufacturer’s application instructions.
Columns, beams, vessel skirts, and tank saddles shall be fireproofed in accordance with the details shown in Section 8. Fireproofing shall have fire-stops as described in paragraph (Lath) in this article.
The required thickness of fireproofing depends on the system being used and the required endurance rating. The required endurance rating is specified in the job specification or on the contract drawings. The thicknesses (in inches, by system) per rating shall be as follows:
- Thickness of applied fireproofing shall be determined by frequent random probings of the wet fireproofing with an approved thickness gauge that is recommended by the fireproofing manufacturer.
  System 1-Hour Rating 2-Hour Rating 3-Hour Rating 4-Hour Rating
  
  Pyrocrete® 241
  
  UL Design XR-702
  11/16 1 1 1/4 1 1/2
  
  Fendolite®
  
  UL Design XR-704
  1 1 7/16 1 13/16 2 1/4
- Dried fireproofing thickness shall be determined by probing and measuring or by measuring flanges. The techniques shall be as described below:
  - Probing and measuring shall be performed by drilling into the fireproofing with a hand- held power drill. The depth of penetration shall then be measured. (Refer to paragraph 6.7 for upgrading and patching.)
  - Measuring flanges shall be performed by measuring the overall thickness of beam or column flanges that have the fireproofing material applied. The original thickness of the steel member shall be subtracted from this measurement, and the resulting dimension is divided by two to yield an average fireproofing thickness on each side of the flange.
- All areas found to be deficient when the thickness is measured shall have sufficient additional fireproofing applied to increase the thickness to the required dimension.
- Company may, at its own discretion and expense, employ an independent testing laboratory to sample and verify the thickness and density of the applied fireproofing in accordance with ASTM E 605. The contractor shall be responsible for correcting any areas found to be deficient as a result of this testing.
Spattering or waste fireproofing shall be cleaned up with scrapers, rags, and soapy water. Fireproofing shall not be allowed to cure before cleanup.
No deep or wide cracks, voids, spalls, or any exposure of the protected metal shall be visible in the dried fireproofing. Dried fireproofing shall conform to the approved sample application (refer to paragraphs 6.3 and 6.7 for sample application, and upgrading and patching).

6.6 Caulking

Caulking shall be applied to all intersections of steel and fireproofing where water might enter due to the ending of fireproofing. Examples are the top flanges of pipe rack beams, the top end of fireproofing on vessel and on tower skirts, and the upper level of column fireproofing. Caulking details are shown in Section 8.

6.7 Upgrading and Patching

Corrective measures shall be taken to upgrade or patch all areas where fire protection materials are deficient or have been damaged or removed. Included are areas where material was removed for testing and areas where material was removed by other trades. Upgrading or patching shall be performed in accordance with the material manufacturer’s recommendations and instructions.
Patches and repairs that are made due to damage by other trades shall be paid for by the trades that caused the damage.

7. CERTIFICATION

The contractor shall prepare a certification document upon completion of the work. This document shall identify the project, the fireproofing material used, the Material Safety Data Sheet (MSDS) for each component, the fire endurance ratings achieved, and shall contain any other pertinent information concerning this application. The completed document shall be submitted to Company.

A completed manufacturer’s official certification form.
A written certificate of compliance with this specification.

8. FIREPROOFING DETAILS

The details shown in Figures 1 through 7 shall be used for applying fireproofing to structural steel, vessel skirts, and tank saddles.

Column Fireproofing Details