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Fireproofing of Building Structural Steel | Technical Specification

 

1.  Purpose of this article is to describe about fireproofing requirements for structural steel in buildings.

2. Fireproofing of Building Structural Steel

This specification applies to structural steel in buildings that are identified in job specifications and engineering drawings as requiring a fireproofing system.

3. Related Codes and Standards

American Society for Testing and Materials (ASTM)

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

E 119      Standard Test Methods for Fire Tests of Building Construction and Materials

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

Underwriters Laboratories Inc. (UL)

Fire Resistance Directory

4. GENERAL

The contractor shall supply all labor, materials, and equipment to ensure a complete fireproofing system for all structural steel as detailed in this specification and as outlined in the job specification or on the contract drawings.

5. MATERIALS

5.1      Fireproofing

Acceptable fireproofing systems and their suppliers are as follows:

System                                             Supplier

  • Pyrocrete 241                     Carboline Company

Protective Coatings and Linings www.carboline.com

5.2      Handling

  1. Fireproofing, bonding agent, and topcoat materials 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.
  2. Any packages of fireproofing, bonding agent, or topcoat materials that are opened or exposed to water prior to use shall be discarded.
  3. Fireproofing, bonding agent, and topcoat materials shall be stored in a dry area, above the ground, until they are ready for use.

5.3      Bonding Agent

  1. A bonding agent might be required to coat the steel prior to the application of the fireproofing material to the steel.
  2. The bonding agent shall be as recommended by the fireproofing material manufacturer and shall be suitable for application over the primer paint used on the steel.
  3. Effectiveness of the bonding agent and compatibility of the bonding agent with the primer paint shall be proven by the contractor by the means of a sample application prior to the general application of the bonding agent. (Refer to paragraph 6.3 for sample application details.)

5.4      Topcoat

Topcoat material might be required over fireproofing material. The topcoat shall be as recommended by the fireproofing material manufacturer and shall be as indicated in the job specification or on the contract drawings.

5.5      Water

The water used to mix the fireproofing material shall be clean, fresh, suitable for domestic consumption, and free of mineral or organic substances that might affect the set of the fireproofing material.

5.6      Primer

  1. A primer might be required to recoat the steel prior to the application of the bonding agent or the fireproofing material.
  2. The primer shall be as recommended by the fireproofing material manufacturer, shall be suitable for application over the primer paint used on the steel, and as indicated in the job specification or on the contract drawings.
  3. 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 ”sample application details”.)

5.7      Submittals

  1.  A material description of the fireproofing, bonding agent (when required), and topcoat shall be submitted to Owner Company by 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.
  2. 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 Air Products.

5.8      Substitutions

  1. Substitutions for materials specified in this specification shall be made only after written approval is obtained from Company.
  2. Approval of a proposed substitution or alternate material will be granted by Owner Company only 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.
  3. Materials containing magnesium-oxychloride, gypsum, or red label solvents shall not be used.
  4. Fireproofing material shall be a factory-mixed, cementitious type, that does not contain any chlorides, sulfates, or asbestos.
  5. Fireproofing material shall be suitable for spray application.
  6. 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.
  7. Fireproofing material shall have been tested by UL in accordance with ASTM E 119 and shall be listed in the UL Fire Resistance Directory.
  8. Fireproofing material shall meet the following fire hazard classifications as tested in accordance with ASTM E 84:
    • Flame Spread:                 10
    • Fuel Contributed:               5
    • Smoke Developed:             0
  9. Fireproofing material shall provide a fire endurance rating for the steel onto which it is applied, as specified in the job specification or on the contract drawings.

6. Building Structural Steel Fireproofing Installation

6.1      General

  1. The bonding agent, fireproofing, and topcoat materials shall be applied in strict accordance with the material manufacturer’s latest dated installation instructions.
  2. Fireproofing shall be installed after all steel is in place.
  3. 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.
  4. Finished surfaces, in-place equipment, piping, acoustical insulation metal liner, and acoustical insulation vapor barrier shall be protected from damage and overspray or spattering by masking, covering, or other appropriate means.
  5. Ambient air and substrate temperature shall be maintained at a minimum temperature of 40°F for 24 hours before and 24 hours after the application of fireproofing.
  6. 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.
  7. Proper air circulation and ventilation to properly dry the fireproofing after its application shall be provided.

6.2      Surface Preparation

  1. 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 Contractor or Company representative. These conditions shall be corrected before the surfaces are covered with fireproofing.
  2. Beginning the fireproofing application shall indicate acceptance of surface conditions. The contractor shall be held accountable for unsatisfactory results.

6.3      Sample Application

  1. The contractor shall prepare a sample application prior to proceeding with the work.
  2. 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 bonding agent 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.
  3. The sample application shall be allowed to cure and shall then be inspected by an Air Products representative. 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.
  4. The sample application shall be used to:
  • Prove the suitability of the bonding agent (when required) used with the primer 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      Bonding Agent Application

The bonding agent, when required, shall be applied to all steel members indicated in the job specification or on the contract drawings as requiring fireproofing.

6.5      Fireproofing Application

  1. Fireproofing shall be applied using the sprayed-in-place method to the steel members indicated in the job specification or on the contract drawings as requiring fireproofing. Certain areas such as the lower part of building columns might require a smooth trowel finish.
  2. Fireproofing shall be applied as thick as required by the appropriate UL design number to obtain the fire endurance rating specified in the job specification or on the contract drawings. Topcoating shall not be used to provide any portion of this thickness.
    • Thickness of applied fireproofing shall be determined by frequent random probings of the fireproofing with an approved measuring device while the fireproofing is still wet. Alternately, fireproofing thickness may be determined by measuring the overall thickness of the beam and column flanges with the fireproofing applied, subtracting the thickness of the steel member, and dividing by two. All areas found to be deficient when thickness is measured shall have sufficient additional fireproofing applied to increase the thickness to the required dimension.
    • Contractor 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.
  3. Spattering or waste fireproofing shall be cleaned up with scrapers, rags, and soapy water. Fireproofing shall not be allowed to cure before cleanup.
  4. 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 paragraph 6.3).

6.6      Topcoat Application

Topcoat material shall be applied over fireproofing as identified in the job specification or on the contract drawings.

Note:   Not all fireproofing requires topcoating.

6.7      Upgrading, Patching, and Repairing

  1. All upgrading, patching, and repairing whether due to the contractor’s deficiencies or to damage by other trades shall be performed according to the material manufacturer’s recommendations and instructions.
  2. 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 Air Products. This document may be either of the certificates listed in paragraphs 7.1.1 and 7.1.2.

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

 

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