THE EFFECT OF REFLECTIVE ROOF COATINGS ON THE … · THE EFFECT OF REFLECTIVE ROOF COATINGS ON THE...

THE EFFECT OF REFLECTIVE ROOF COATINGS ON THE

DURABILITY OF ROOF SYSTEMS

Joseph W. Mellott II and Donald C. PortfolioROOF COATING MANUFACTURERS ASSOCIATION

International Roofing Expo

TU-03 Technical

March 6, 2007

Las Vegas, NV

AIA CREDITS

Hanley Wood is a Registered Provider with The American Institute of Architects Continuing Education Systems. Credit earned on completion of this program will be reported to CES Records for AIA members. Certificates of Completion for non-AIA members available on request.

AIA CREDITS

This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

LEARNING OBJECTIVES

Recognize the effect of reflective roofing on aging of roofing membranesIdentify the differences in reflectance of various reflective materialsDistinguish the resultant differences in natural weathering at three different US locationsIdentify physical properties of asphalt and roofing membranes to help understand measurable aging properties of the membrane (substrate)

BACKGROUND

1997 Roof Coating Manufacturers (RCMA) Association Technical Committee– Research program with Oak Ridge National

Laboratory (ORNL)– Heat Transfer through roofing systems related to

reflectance and emittance of systemUn-CoatedAluminum Roof CoatingsWhite Elastomeric Roof Coatings

COATINGS TESTED

Aluminum Roof Coating (Non-Fibrated)Aluminum Roof Coating (Fibrated – Good)Aluminum Roof Coating (Fibrated – Medium)Aluminum Roof Coating (Fibrated – Economy)White Elastomeric Coating (Acrylic)White Elastomeric Coating (Styrene-Acrylic)

COATING FORUMLATIONS

Aluminum Roof Coatings– Generic Formulations (Group Agreement)

White Elastomeric– Starting Formulations from 3

manufacturers of latex used in the coatings– Two types

AcrylicStyrene Acrylic

ROOFING MEMBRANE

4 – Ply Glass Built-Up Roofing MembraneSurfacing– Aluminum Coating (NF): 1 gal/sq in 2 coats– Aluminum Coating (F): 1.5 – 2 gal/sq in two

coats– White Elastomeric: 1.5 gal/sq in 2 coats– Nothing

SCOPE OF PROJECT

Original Primary (ORNL)– Effect of reflectance and emittance on heat

transfer through roofing membrane– Effect of weathering on reflectance and

emittance over three yearsSecondary (RCMA)– Effect of reflectance properties of the BUR

membrane system over time

RESULTS ASPHALT PROPERTIES

Coating Type

Ref. Initial

Ref. 3 Yr

SP. °F 3 Yr

Δ SP, °F

Pen, dmm3 Yr

Δ Pen, dmm

White SA 0.86 0.52 109 5 8 4

Al-F Med 0.64 0.34 118 14 6 6

Al-NF 0.71 0.39 124 20 4 7

None 0.06 0.06 131 27 4 7

ASPHALT PROPERTIES

Both increase in softening point and decrease in penetration are measures of asphalt aging

CONCLUSIONSReflective coatings result in a measurable effect on the change of asphalt properties measuredReflective coatings result in a smaller increase in softening point and decrease in penetration than a non-reflective surface

CONCLUSIONSThe asphalt properties measured are associated with the aging of asphaltReflective coatings decrease the rate at which asphalt ages in a BUR systemThere is need for more work due to inadequate design of original work

WHY THE INTEREST IN MEMBRANE PROPERTIES?It Can Be Difficult to Justify Cool Roofing Just in Terms of Energy SavingsInsulation Can Be a Better Energy Savings Choice than a White Coating –Insulation Does Not Have to be Cleaned Periodically and Does Not Have to be Replaced (Re-coated) Periodically

WHY THE INTEREST IN MEMBRANE PROPERTIES?Insulation Causes Higher Temperatures in the Membrane Than No InsulationA White “Cool” Coating Applied to an Insulated or Non-Insulated Roofing System Can Reduce the Temperature of the Membrane

RCMA: The Next Step

Based on the data generated in the preliminary study at Oakridge National Laboratories, The RCMA launched a new study in 2003.

Coating Durability Membrane Performance

Multi-year Project to Determine the Effect of Roof Coatings on Membrane Performance and Weathering Performance of

Coatings

Selection of Coatings

How Were the Coatings Selected?

3 manufacturers of each type selected at random3 manufacturers submitted blind samples1 of the samples chosen for the study

The Substrates

BUR– 2 Plies of Type IV Glass and 1 G2 Base in Type IV

Asphalt

SBS– G2 Base, SBS Cap in Type IV Asphalt

APP– G2 Base, APP Smooth – Torched

EPDM– 45 mil (Black)

Insulation/Deck– ½ Plywood, 2” Iso + ½” Cover board

Deck Design

2 square feet per section8 separate sectionsBuilt for Testing Not as RoofingAllows for 4 separate testsSmall Initial Deck produced for Initial Test

Location of Decks

Northeast OhioWarm, Cold, Wet, Dry

South FloridaHot, Wet

ArizonaHot, Dry

Testing Protocol for BUR, SBS and APP Decks

Tensile / ElongationReflectanceSoftening PointPenetrationIatroscanDSR

Testing Protocol for EPDM Deck

Tensile / ElongationReflectanceCold Bend Thickness

Coating PerformanceSEBS Solvent Based White Elastomeric Coating

20

30

40

50

60

70

80

90

SBS APP EPDM BUR

Ref

lect

ance

Original on Substrate NEO 6 months on Substrate NEO 10 months on Substrate NEO 17 months on Substrate NEO22 months on Substrate NEO 30 months on Substrate NEO 37 months on Substrate in NEO Original on Substrate FLA5 months on Substrate FLA 9 months on Substrate FLA 16 months on Substrate in FLA

Coating PerformanceAcrylic White Elastomeric Coating

20

30

40

50

60

70

80

90

SBS APP EPDM BUR

Roofing System Type

Ref

lect

ance

Original on Substrate NEO 6 months on Substrate NEO 10 months on Substrate NEO 17 months on Substrate NEO22 months on Substrate NEO 30 months on Substrate NEO 37 mos. on Substrate in NEO Original on Substrate FLA5 months on Substrate FLA 9 months on Substrate FLA 16 months on Substrate in FLA

Coating PerformanceStyrene Acrylic White Elastomeric Coating

20

30

40

50

60

70

80

90

SBS APP EPDM BUR

Roof System Type

Ref

lect

ance

Original on Substrate NEO 6 months on Substrate NEO 10 months on Substrate NEO 17 months on Substrate NEO22 months on Subtrate NEO 30 months on Substrate NEO 37 months on Substrate in NEO Original on Substrate FLA5 months of Substrate FLA 9 months on Substrate FLA 16 months on Substrate in FLA

Coating PerformanceHigh Softening Point Asphalt Aluminum Coating

20

30

40

50

60

70

80

90

SBS APP EPDM BUR

Roofing System Type

Ref

lect

ance

Original on Substrate NEO 1 Year on Substrate NEO 16 months on Substrate NEO 23 months on Substrate NEO28 months on Substrate NEO 36 months on Substrate NEO 43 months on Substrate in NEO Original on Substrate FLA5 months on Substrate FLA 9 months on Substrate FLA 16 months on Substrate in FLA

Coating PerformanceLow Softening Point Asphalt Aluminum Coating

20

30

40

50

60

70

80

90

SBS APP EPDM BUR

Roofing System Type

Ref

lect

ance


Coating PerformanceWater Based Asphalt Aluminum Coating

20

30

40

50

60

70

80

90

SBS APP EPDM BUR

Roofing System Type

Ref

lect

ance


Coating PerformanceAsphalt Emulsion

0

2

4

6

8

10

12

14

16

18

20

SBS APP EPDM BUR

Roofing System Type

Ref

lect

ance


Membrane Initial PropertiesProperty ResultsMembrane Identification APP SBS BURSoftening Point, °F 306 249 231Penetration, dmm 16 22 10Tensile Strength, Peak Load, MD, lbf. 123 123 271Elongation, at Peak Load, MD, % 51 34 3.2

Iatroscan Composition

Saturates, % 16.2 13.9 TBDAromatics, % 39.7 24.2 TBDResins, % 36.5 52.7 TBDAsphaltenes, % 7.6 9.2 TBD

DSR TBD TBD TBD

Membrane Initial Properties

Property Results

Membrane Identification EPDM

Thickness, in. 0.435

Tensile Strength, psi 1389

Ultimate Elongation, % 893

Tear Resistance, lbf. 10

DECKS – TAMPA, FL 2005

SBS

EPDMBURAPP

DECKS IN FLORIDA

APP

AcrylicStyrene Acrylic

High SP ALLow SP AL

Water Based AL

Asphalt Emulsion

SEBS

DECKS IN FLORIDA

SBS

DECKS IN FLORIDA

BUR

DECKS IN FLORIDA

EPDM

TYPICAL DIFFERENCES

Styrene-Acrylic Acrylic

TYPICAL DIFFERENCES

WB Low SP High SP

DECKS IN NE OHIO 11-06

SEBS Acrylic

Sty. Acrylic

High SP Al

Low SP Al

Al Emulsion

Asphalt Emulsion

APP


BUR


EPDM


SBS

DECKS IN FLORIDA – 12/2006

Acrylic

Styrene AcrylicHigh SP AL

Low SP ALWater Based ALAsphalt Emulsion

SEBS

APP


SBS


BUR


EPDM

INTERIM RESULTSOUTDOOR WEATHERING

Styrene Acrylic Coating is Performing Significantly Better than Acrylic CoatingLow Softening Point Aluminum Coating is Performing Slightly Better Than High Softening Point Aluminum and Water Based AluminumPerformance of Roof Coatings does not appear to be very Substrate Dependent in the long term

CONCLUSIONS – PART II

Expected Four Years After Initial Membrane SamplingInterim Reflectance Measurements Will Be Determined at Approximate Six Month Intervals

ACKNOWLEDGEMENTS

Deck Construction– Momentum Technologies– SR Roofing Products

Outdoor Weathering and Testing– Henry Company– Momentum Technologies– PRI Asphalt Technologies

THANK YOU

This concludes the American Institute of Architects Continuing Education Systems Program.

QUESTIONS?

Donald C. Portfolio: PRI Construction Materials Technologies, Tampa, FL

Joseph W. Mellott II: The Garland Company, Cleveland, OH

THE EFFECT OF REFLECTIVE ROOF COATINGS ON THE … · THE EFFECT OF REFLECTIVE ROOF COATINGS ON THE...

Documents

Transcript of THE EFFECT OF REFLECTIVE ROOF COATINGS ON THE … · THE EFFECT OF REFLECTIVE ROOF COATINGS ON THE...