Recap: FIRE RESISTANCE FOR STRUCTURAL STEEL - FIREPROOFING 03/25/2021
Craig Boucher from GCP Applied Technologies put on an excellent program on Fire Resistance for Structural Steel - Fireproofing. This was a one hour AIA Cont. Education Program (1 LU credits). The program was FREE for CSI Syracuse Chapter members, and $20 for non-members. We were requested not to post the zoom recording, but the slides were made available. Michael Kulik, CSI, CDT, CCCA provided a recap of this program by providing his supplimental notes shown below.
Description: Learn about the application of passive fire protection systems for structural steel buildings. After a brief overview of the purpose of fireproofing products, the audience is introduced to the tests that evaluate product performance, and proper UL Design selection. Case studies and building code requirements are included as part of this presentation as well, helping the audience to depart with a basic understanding of the specification, selection, and application of spray-applied fireproofing products.
Learning Objectives: After this presentation the audience will understand:
1. The purpose of spray-applied fire resistive materials (SFRM)
2. Fire test procedures & acceptance criteria
3. Building code requirements for SFRM
4. In-place performance of SFRM and Third Party Special Inspection procedures
5. Different SFRM products and where they are used in a building
6. Critical fireproofing issues (Restrained/Unrestrained, patching, primers, etc.)
Presentation Slides & Additional Resources: Restricted to Members Only
CSI Syracuse Chapter Presentation Supplemental Notes:
Prepared By Michael Kuilik
Types of active fireproofing systems are: (1) wet and dry sprinkler systems; (2) gas suppression systems (common gases carbon dioxide, inert gases, halon, and clean agents such as HFC-227ea that can put out fires without damaging equipment); (3) and there are foam suppression systems (a type of wet system where foam smothers the fire).
The types of passive fireproofing systems include: (1) gypsum wallboard and similar materials; (2) rated ceiling types; (3) and spray-applied fire resistive materials (spray fireproofing).
Spray-applied fire-resistive materials are composed of binding agents (gypsum or cement) and contain other fibrous non-combustible material. This material is mixed in the field and is typically sprayed on the structural steel or can be troweled on for a smoother finish. The purpose of applying spray fire resistive materials (SFRM) to steel is due the fact that approximately 50% of the load carrying capacity of steel is lost when the ambient temperature of a space reaches 1100 degrees Fahrenheit.
ASTM E119, Fire Test Standard, introduced steel and floor assemblies being classified as “restrained” and “unrestrained” based on a series of furnace tests. Restrained assemblies are able to sustain the applied load longer under the heat within the furnace than an unrestrained assembly.
An important consideration for the design of spray applied fireproofing is confirming if the assembly is restrained or unrestrained. The New York State Building Code (based on the International Building Code (IBC) states in Chapter 7, Fire and Smoke Protection Features, that an assembly shall be by default classified as unrestrained.
703.2.3 Restrained Classification
Fire-resistance-rated assemblies tested under ASTM E119 or UL 263 shall not be considered to be restrained unless evidence satisfactory to the building official is furnished by the registered design professional showing that the construction qualifies for a restrained classification in accordance with ASTM E119 or UL 263. Restrained construction shall be identified on the construction documents.
In general the description of a restrained assembly is a beam that is mechanically fixed to the rest of the structure so that the normal elongation of a steel beam within a fire is restrained, creating compression that results in better structural performance of the assembly. In contrast, building assembled without a fully fixed mechanical connection between the beams the composite slab. In this design, each element moves separately and in different elongations. To safely address this condition, a thicker layer of SFRM material is required. An unrestrained assembly, being more stringent, will cost more to apply spray-fireproofing materials.
The requirement for spray-applied fireproofing thickness is affected by the building heights. Taller buildings require higher bond strengths. Further considerations are taking the measurement from the lowest level of emergency access to the highest level of occupied space.
During the bidding and construction process, a lot of questions arise as to what type of fireproofing is required for each location. For example considerations are based on what remains exposed (subject to contact and damage) affecting durability. Of similar concern, the type of spray-applied fire protection material that must be applied during construction that will remain (temporarily) exposed to the elements prior to the building being “dried-in” must also be considered.
Manufacturer’s like GCP Applied Technologies make different products that can be used in different applications throughout a building project. When working in an existing building where patching of fireproofing is required, the existing fireproofing must be positively identified for the proper cohesion and adhesions with the new fireproofing mix. In both cases, it is best to work directly with a SFRM representative directly, will result in the best solution and cost for the project. For patching, see the UL directory for patching SFRM or the NFCA Handbook of Accepted Fireproofing Knowledge publication.
The section of the New York State building code that addresses the required SFRM inspections is Chapter 17 Inspections and Tests.
1705.14 Sprayed Fire-Resistant Materials
Special inspections and tests of sprayed fire-resistant materials applied to floor, roof and wall assemblies and structural members shall be performed in accordance with Sections 1705.14.1 through 1705.14.6. Special inspections shall be based on the fire-resistance design as designated in the approved construction documents. The tests set forth in this section shall be based on samplings from specific floor, roof and wall assemblies and structural members. Special inspections and tests shall be performed after the rough installation of electrical, automatic sprinkler, mechanical and plumbing systems and suspension systems for ceilings, where applicable.
1705.14.1 Physical and Visual Tests
The special inspections and tests shall include the following to demonstrate compliance with the listing and the fire-resistance rating:
Condition of substrates.
Thickness of application.
Density in pounds per cubic foot (kg/m3).
Bond strength adhesion/cohesion.
Condition of finished application.
Additional considerations discussed during this presentation was, additional materials that can be applied over SFRM. The most important consideration is that spray-fireproofing resistive materials can be painted. Most latex based paints are compatible, but in any case, confirm with both the SFRM and the paint manufacturer for compatibility. A tip provided by the presenter, Craig Boucher, was that in cases where the SFRM is to remain exposed but are desired to be painted, the mix can be troweled on to the correct thickness for a smoother (painted) appearance.
Incidentally, there are only three major fire proofing manufacturers in the United States.
Lastly, Craig discussed aspects of intumescent fireproofing; the durability issues with fiber based SFRM, and the most common design error language.
MasterFormat No:
07800 Applied Fireproofing
