Transcript Module One - PaintSquare

Fire Resistant Coatings
Presented by:
Jayson L. Helsel, P.E.
KTA-Tator, Inc.
Learning Objectives
Comprehension of the Fire Resistant Webinar
will enable the participant to:
how intumescent coatings protect underlying steel
 Describe
from heat exposure
the US authority that evaluates and approves
 Identify
intumescent coatings
 List two fire rating classification tests that are used to
qualify intumescent coatings for use in building construction
two primary resin types that are used to formulate
 Identify
intumescent coatings
Learning Objectives (cont.)
characteristics of the resin systems used to formulate
 List
intumescent coatings
 Explain how steel size and structure design affect specified
thickness and number of coats
the methods used to improve the appearance of
 Describe
the texture of intumescent coatings
a method to measure the hardness of the applied
 Describe
coating to assess cure
 Identify the generic types of primer and finish coats
commonly used in conjunction with intumescent coatings
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)
Fire Resistant Coatings
Intumescent Coatings:
– Are categorized as SFRMs
– Similar to conventional coatings
– Have unique fire resistant properties
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
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
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
www.ul.com
Fire Resistance Classifications
Certifications are “design” specific by
coating manufacturer
Numbering system defines an
alphanumeric design number
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
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
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
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
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)
Fire Resistance Classifications
Technical Manual 12-B
– Scope
– General Information
– Substrate Conditions
– Site Conditions
– Inspection Procedures
– Method of Tests
– Conditions of Finished Application
– Patching
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
Fire Resistance Classifications
ANSI/UL 263 Classified Coatings
– Typical use for structural steel in
commercial structures
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
Fire Resistance Classifications
ANSI/UL 1709 Classified Coatings
– Typical use for steel structures at
petrochemcial facilities, e.g.
Chemical plant
Refineries
Offshore oil platforms
Other Approvals
Intumescent coatings may also need
approval by city building codes
Coating manufacturers should provide
approvals as applicable
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
Generic Coating Types
Acrylic/vinyl
Thin-film coating
Solvent or water-based
Single component
Typically rated under UL 263
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.
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
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
Generic Coating Comparison
Coating Type
Required Number
Thickness of Coats
(mils)
Solvent-based acrylic
130
5
Recoat
Time
(between
coats)
@50ºF
24 hours
Time to
Finish
Coat
@50ºF
Solvent-based vinyl
375
4
4 hours
20+ days
Water-based acrylic
180
6
8 hours
10+ days
Epoxy
180
1
n/a
24 hours
Epoxy w/mesh
340
1-2
n/a
48 hours
25 days
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”
Testing for Coating Cure
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)
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
Use of Primers
Intumescent coating manufacturer may
have approved list of primers
– Types include alkyd, acrylic, epoxy and
zinc-rich
– Application thickness important
Primers
Function of primer
– Provides adhesion to substrate
– Provides suitable surface for intumescent
– Provides additional barrier protection
Can also provide inhibitive or sacrificial
protection
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
Finish Coats
Function of topcoat
– Color and gloss
– Abrasion resistance
– Chemical resistance
– Washability
– Resistance to the environment
Finish Coats
Acrylics
– Advantages
Single component
Ease of application
Color & gloss retention
Flexibility
Low VOC content for waterbased
Finish Coats
Acrylics
– Limitations
Limited alkali and solvent resistance
Moderate abrasion resistance
Application temperature >50ºF for waterbased
Finish Coats
Urethanes
– Advantages
Color & gloss retention (aliphatic)
Adhesion
Acid, alkali resistant
Chemical resistant
Impact/abrasion resistant
Finish Coats
Urethanes
– Limitations
Multi-component
Short recoat intervals
Limited pot life
Moisture sensitive during cure
Difficult to recoat
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
Fire Resistive Coatings
Questions?