1. Fire Resistant Coatings
Presented by:
Jayson L. Helsel, P.E.
KTA-Tator, Inc.

2. Learning Objectives
Comprehension of the Fire Resistant Webinar will enable the participant to:
Describe how intumescent coatings protect underlying steel from heat exposure
Identify the US authority that evaluates and approves intumescent coatings
List two fire rating classification tests that are used to qualify intumescent coatings for use in building construction
Identify two primary resin types that are used to formulate intumescent coatings

3. Learning Objectives (cont.)
List characteristics of the resin systems used to formulate intumescent coatings
Explain how steel size and structure design affect specified thickness and number of coats
Describe the methods used to improve the appearance of the texture of intumescent coatings
Describe a method to measure the hardness of the applied coating to assess cure
Identify the generic types of primer and finish coats commonly used in conjunction with intumescent coatings

4. Fire Resistant Coatings
Sprayed Fire Resistive Materials (SFRM) are broad group of materials including:
Cementitious and gypsum based materials
Intumescent coatings
(Note: There is a separate category for “Fire Retardent” coatings, which are not reviewed here)

5. Fire Resistant Coatings
Intumescent Coatings:
Are categorized as SFRMs
Similar to conventional coatings
Have unique fire resistant properties

6. Intumescent Coatings How they function:
Intumescent coatings char and swell when exposed to fire/heat
The charred layer acts to insulate the steel from fire

7. Intumescent Coatings Performance ratings
Coatings rated by how long steel is protected at specified thickness
Ratings from 1 to 3 hours (at 30 minute intervals
Specific to shape/size of steel, e.g. W10 x 49 column

8. Fire Resistance Classifications
Underwriters Laboratories (UL) is recognized authority that evaluates and approves intumescent coatings for a certain classification and fire rating
Certifications can be verified online at

11. Fire Resistance Classifications
Certifications are “design” specific by coating manufacturer
Numbering system defines an alphanumeric design number

14. Fire Resistance Classifications
Beams
W, M or S shaped steel sections (AISC)
Minimum beam size for fire resistance is expressed as W/D ratio
W = weight of beam per lineal foot
D = perimeter of protection material
Beams of same configuration with greater W/D ratio may be used in design

15. Fire Resistance Classifications
Columns
Minimum column size and configuration specified in X and Y series designs
Same hourly rating applies when section with equal or greater W/D ratio is substituted for same configuration

16. Fire Resistance Classifications
Beams and Columns
Required coating thickness increases as weight of steel decreases
Lighter steel heats up more rapidly and requires more protection

17. Fire Resistance Classifications
Intumescent (and Mastic) Coatings
Coating thickness specification in a design is minimum average thickness measured in accordance with Technical Manual 12-B
Average thickness should not exceed maximum thickness published (if listed) in individual designs or by
No individual measurement <80% of specified design thickness

18. Fire Resistance Classifications
Technical Manual 12-B
Published by Association of the Wall and Ceiling Industries (AWCI International)
Individual measurement = average of 3 gauge readings (similar to SSPC-PA 2)
Testing frequency one bay per floor or one test per 10,000 square feet (further defines required shapes)

21. Fire Resistance Classifications
Technical Manual 12-B
Scope
General Information
Substrate Conditions
Site Conditions
Inspection Procedures
Method of Tests
Conditions of Finished Application
Patching

22. Fire Resistance Classifications
ANSI/UL 263
Used for resistance to cellulosic fire (e.g. combustion of wood or building materials)
Slower rise in temperature
1000 F at 5 min.; 1550 F at 30 min.; 1700 F at 60 min.; 1925 F at 180 min.; 2000 F at 240 min.
Interior and exterior exposures

23. Fire Resistance Classifications
ANSI/UL 263 Classified Coatings
Typical use for structural steel in commercial structures

24. Fire Resistance Classifications
ANSI/UL 1709
Used for resistance to a hydrocarbon fire
Rapid rise in temperature
2000 F at 5 minutes
Interior and exterior exposures
Environmental tests include, accelerated aging, high humidity, salt spray, thermal cycling for exterior exposure

25. Fire Resistance Classifications
ANSI/UL 1709 Classified Coatings
Typical use for steel structures at petrochemcial facilities, e.g.
Chemical plant
Refineries
Offshore oil platforms

32. Other Approvals
Intumescent coatings may also need approval by city building codes
Coating manufacturers should provide approvals as applicable

34. Generic Coating Types
Intumescent coatings are generally the following generic resin types:
Acrylic/vinyl
Epoxy
Intumescents are also generally categorized as “thin-film” or “thick-film” coatings

35. Generic Coating Types Acrylic/vinyl Thin-film coating
Solvent or water-based
Single component
Typically rated under UL 263

36. Generic Coating Types Acrylic/vinyl Applied in several coats
Time-frame for a complete application may span several days
Additional time may be needed before application of any required exterior finish coat.

37. Generic Coating Types Epoxy Thick-film coating
Applied by plural component spray equipment in one or two coats
Rapid cure
Typically rated under UL 1709

38. Generic Coating Types Epoxy
May require mesh reinforcement (e.g. metal, fiberglass, carbon)
Typically requires the use of applicators licensed or approved by the coating manufacturer

39. Generic Coating Comparison
Coating Type
Required Thickness (mils)
Number of Coats
Recoat Time (between
Time to Finish
Solvent-based acrylic
130 5
24 hours
25 days
Solvent-based vinyl
375 4
4 hours
20+ days
Water-based acrylic
180 6
8 hours
10+ days
Epoxy 1
n/a
Epoxy w/mesh
340
1-2
48 hours

40. Testing for Coating Cure
Intumescents may require testing for proper cure
Typical test is Durometer Hardness (Shore D)
Resistance of coating film to indentation by Durometer instrument
ASTM D2240, “Standard Test Method for Rubber Property-Durometer Hardness”

41. Testing for Coating Cure

42. Coating Appearance
Intumescents generally have a rough or orange peel appearance
Methods to improve include:
Back rolling following spray application
Sanding (not recommended)
Finish coat application (may be required)

46. Coating Systems
Intumescent design approvals typically include a primer and/or finish coat
When included in design primer/finish must be applied to meet fire rating
Primer/finish must be endorsed by intumescent coating manufacturer
Preference always for same manufacturer

47. Use of Primers
Intumescent coating manufacturer may have approved list of primers
Types include alkyd, acrylic, epoxy and zinc-rich
Application thickness important

48. Primers Function of primer Provides adhesion to substrate
Provides suitable surface for intumescent
Provides additional barrier protection
Can also provide inhibitive or sacrificial protection
The primer is the first coating layer of the system. It provides adhesion of the coating system to the underlying substrate and must provide a suitable surface for the next coat. Depending on its formulation, the primer may provide barrier, inhibitive or sacrifical protection, often a combination of these. The primer most often is the coat employing sacrificial protection, as with zinc primers.

49. Use of Finish Coat
May be required in design approval for exterior exposure
Intumescent coating manufacturer must endorse finish material
Types include 100% acrylic and aliphatic urethane coatings
May affect/improve appearance

50. Finish Coats Function of topcoat Color and gloss Abrasion resistance
Chemical resistance
Washability
Resistance to the environment
The function of the top coat is for both aesthetics and corrosion protection. The top coat provides the final color and gloss, abrasion and chemical resistance, washability, and resistance to the environment.

51. Finish Coats Acrylics Advantages Single component Ease of application
Color & gloss retention
Flexibility
Low VOC content for waterbased
Add after alkyds, delete all Calcium Suflonate Alkyd slides on Pg 2-18 & 2-19
Notes for slide:
Silicone alkyds combine the excellent adhesion and easy handling properties of the alkyds with the exterior durability of the silicone resin. The coating cures by air drying and oxidation which may be slow.
Typical coating application is for hulls and superstructures on ships. The significantly improved weathering properties as compared to alkyds include gloss and color retention and resistance to chalking.

52. Finish Coats Acrylics Limitations
Limited alkali and solvent resistance
Moderate abrasion resistance
Application temperature >50ºF for waterbased
Add after alkyds, delete all Calcium Suflonate Alkyd slides on Pg 2-18 & 2-19
Notes for slide:
Silicone alkyds combine the excellent adhesion and easy handling properties of the alkyds with the exterior durability of the silicone resin. The coating cures by air drying and oxidation which may be slow.
Typical coating application is for hulls and superstructures on ships. The significantly improved weathering properties as compared to alkyds include gloss and color retention and resistance to chalking.

53. Finish Coats Urethanes Advantages Color & gloss retention (aliphatic)
Adhesion
Acid, alkali resistant
Chemical resistant
Impact/abrasion resistant
Add after alkyds, delete all Calcium Suflonate Alkyd slides on Pg 2-18 & 2-19
Notes for slide:
Silicone alkyds combine the excellent adhesion and easy handling properties of the alkyds with the exterior durability of the silicone resin. The coating cures by air drying and oxidation which may be slow.
Typical coating application is for hulls and superstructures on ships. The significantly improved weathering properties as compared to alkyds include gloss and color retention and resistance to chalking.

54. Finish Coats Urethanes Limitations Multi-component
Short recoat intervals
Limited pot life
Moisture sensitive during cure
Difficult to recoat
Add after alkyds, delete all Calcium Suflonate Alkyd slides on Pg 2-18 & 2-19
Notes for slide:
Silicone alkyds combine the excellent adhesion and easy handling properties of the alkyds with the exterior durability of the silicone resin. The coating cures by air drying and oxidation which may be slow.
Typical coating application is for hulls and superstructures on ships. The significantly improved weathering properties as compared to alkyds include gloss and color retention and resistance to chalking.

55. Summary of Key Points When specifying intumescents consider:
Required UL approval
City building code approval
Include required primer and finish coats
Applicator certification if needed (e.g. plural component materials)
Include test sections to evaluate appearance

56. Fire Resistive Coatings
Questions?