THE EFFECT OF REFLECTIVE ROOF COATINGS ON THE DURABILITY OF ROOF SYSTEMS

Transcription

1 THE EFFECT OF REFLECTIVE ROOF COATINGS ON THE DURABILITY OF ROOF SYSTEMS Joseph W. Mellott II and Donald C. Portfolio ROOF COATING MANUFACTURERS ASSOCIATION International Roofing Expo TU-03 Technical March 6, 2007 Las Vegas, NV

2 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.

3 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.

4 LEARNING OBJECTIVES Recognize the effect of reflective roofing on aging of roofing membranes Identify the differences in reflectance of various reflective materials Distinguish the resultant differences in natural weathering at three different US locations Identify physical properties of asphalt and roofing membranes to help understand measurable aging properties of the membrane (substrate)

5 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 system Un-Coated Aluminum Roof Coatings White Elastomeric Roof Coatings

6 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)

7 COATING FORUMLATIONS Aluminum Roof Coatings Generic Formulations (Group Agreement) White Elastomeric Starting Formulations from 3 manufacturers of latex used in the coatings Two types Acrylic Styrene Acrylic

8 ROOFING MEMBRANE 4 Ply Glass Built-Up Roofing Membrane Surfacing Aluminum Coating (NF): 1 gal/sq in 2 coats Aluminum Coating (F): gal/sq in two coats White Elastomeric: 1.5 gal/sq in 2 coats Nothing

9 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 years Secondary (RCMA) Effect of reflectance properties of the BUR membrane system over time

10 RESULTS ASPHALT PROPERTIES Coating Type Ref. Initial Ref. 3 Yr SP. F 3 Yr Δ SP, F Pen, dmm 3 Yr Δ Pen, dmm White SA Al-F Med Al-NF None

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

12 CONCLUSIONS Reflective coatings result in a measurable effect on the change of asphalt properties measured Reflective coatings result in a smaller increase in softening point and decrease in penetration than a nonreflective surface

13 CONCLUSIONS The asphalt properties measured are associated with the aging of asphalt Reflective coatings decrease the rate at which asphalt ages in a BUR system There is need for more work due to inadequate design of original work

14 WHY THE INTEREST IN MEMBRANE PROPERTIES? It Can Be Difficult to Justify Cool Roofing Just in Terms of Energy Savings Insulation 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

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

16 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.

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

18 Selection of Coatings

19 How Were the Coatings Selected? 3 manufacturers of each type selected at random 3 manufacturers submitted blind samples 1 of the samples chosen for the study

20 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

21 Deck Design 2 square feet per section 8 separate sections Built for Testing Not as Roofing Allows for 4 separate tests Small Initial Deck produced for Initial Test

22 Location of Decks Northeast Ohio Warm, Cold, Wet, Dry Arizona Hot, Dry South Florida Hot, Wet

23 Testing Protocol for BUR, SBS and APP Decks Tensile / Elongation Reflectance Softening Point Penetration Iatroscan DSR

24 Testing Protocol for EPDM Deck Tensile / Elongation Reflectance Cold Bend Thickness

25 Coating Performance SEBS Solvent Based White Elastomeric Coating Reflectance SBS APP EPDM BUR Original on Substrate NEO 6 mont hs on Subst rat e NEO 10 mont hs on Subst rat e NEO 17 months on Substrat e NEO 22 months on Substrate NEO 30 months on Subst rat e NEO 37 mont hs on Subst rat e in NEO Original on Subst rat e FLA 5 months on Substrate FLA 9 months on Substrate FLA 16 months on Substrate in FLA

26 Coating Performance Acrylic White Elastomeric Coating Reflectance SBS APP EPDM BUR Roofing System Type Original on Subst rat e NEO 6 months on Substrate NEO 10 mont hs on Subst rat e NEO 17 months on Substrate NEO 22 months on Substrate NEO 30 mont hs on Subst rat e NEO 37 mos. on Substrate in NEO Original on Subst rat e FLA 5 months on Substrate FLA 9 months on Substrate FLA 16 mont hs on Subst rat e in FLA

27 Coating Performance Styrene Acrylic White Elastomeric Coating Reflectance SBS APP EPDM BUR Roof System Type Original on Substrate NEO 6 months on Substrate NEO 10 months on Substrate NEO 17 months on Substrate NEO 22 months on Subtrate NEO 30 months on Substrate NEO 37 months on Substrate in NEO Original on Subst rat e FLA 5 months of Substrate FLA 9 months on Substrate FLA 16 months on Substrate in FLA

28 Coating Performance High Softening Point Asphalt Aluminum Coating Reflectance SBS APP EPDM BUR Roofing System Type Original on Substrate NEO 1 Year on Substrate NEO 16 months on Substrate NEO 23 months on Substrate NEO 28 months on Substrate NEO 36 months on Substrate NEO 43 months on Substrate in NEO Original on Substrate FLA 5 months on Substrate FLA 9 months on Substrate FLA 16 months on Substrate in FLA

29 Coating Performance Low Softening Point Asphalt Aluminum Coating Reflectance SBS APP EPDM BUR Roofing System Type Original on Substrate NEO 1 Year on Substrate NEO 16 months on Substrate NEO 23 months on Substrate NEO 28 months on Substrate NEO 36 months on Substrate NEO 43 months on Substrate in NEO Original on Substrate FLA 5 months on Substrate FLA 9 months on Substrate FLA 16 months on Substrate in FLA

30 Coating Performance Water Based Asphalt Aluminum Coating Reflectance SBS APP EPDM BUR Roofing System Type Original on Subst rat e NEO 1 Year on Substrate NEO 16 mont hs on Subst rat e NEO 23 mont hs on Subst rat e NEO 28 months on Substrate NEO 36 months on Substrate NEO 43 months on Substrate in NEO Original on Substrate FLA 5 months on Substrate FLA 9 months on Substrate FLA 16 months on Substrate in FLA

31 Coating Performance Asphalt Emulsion Reflectance SBS APP EPDM BUR Roofing System Type Original on Subst rat e NEO 1 Year on Substrate NEO 16 mont hs on Subst rat e NEO 23 months on Substrate NEO 28 mont hs on Subst rat e NEO 36 months on Substrate NEO 43 months on Substrate in NEO Original on Substrate FLA 5 months on Substrate FLA 9 months on Substrate FLA 16 months on Substrate in FLA

32 Membrane Initial Properties Property Results Membrane Identification APP SBS BUR Softening Point, F Penetration, dmm Tensile Strength, Peak Load, MD, lbf Elongation, at Peak Load, MD, % Iatroscan Composition Saturates, % TBD Aromatics, % TBD Resins, % TBD Asphaltenes, % TBD DSR TBD TBD TBD

33 Membrane Initial Properties Property Membrane Identification Results EPDM Thickness, in Tensile Strength, psi 1389 Ultimate Elongation, % 893 Tear Resistance, lbf. 10

34 DECKS TAMPA, FL 2005 APP BUR EPDM SBS

35 DECKS IN FLORIDA SEBS Acrylic Styrene Acrylic High SP AL Low SP AL Water Based AL Asphalt Emulsion APP

36 DECKS IN FLORIDA SBS

37 DECKS IN FLORIDA BUR

38 DECKS IN FLORIDA EPDM

39 TYPICAL DIFFERENCES Styrene-Acrylic Acrylic

40 TYPICAL DIFFERENCES WB Low SP High SP

41 DECKS IN NE OHIO SEBS Acrylic Sty. Acrylic High SP Al Low SP Al Al Emulsion Asphalt Emulsion APP

42 DECKS IN NE OHIO BUR

43 DECKS IN NE OHIO EPDM

44 DECKS IN NE OHIO SBS

45 DECKS IN FLORIDA 12/2006 Asphalt Emulsion Water Based AL Low SP AL High SP AL Styrene Acrylic Acrylic SEBS APP

46 DECKS IN FLORIDA 12/2006 SBS

47 DECKS IN FLORIDA 12/2006 BUR

48 DECKS IN FLORIDA 12/2006 EPDM

49 INTERIM RESULTS OUTDOOR WEATHERING Styrene Acrylic Coating is Performing Significantly Better than Acrylic Coating Low Softening Point Aluminum Coating is Performing Slightly Better Than High Softening Point Aluminum and Water Based Aluminum Performance of Roof Coatings does not appear to be very Substrate Dependent in the long term

50 CONCLUSIONS PART II Expected Four Years After Initial Membrane Sampling Interim Reflectance Measurements Will Be Determined at Approximate Six Month Intervals

51 ACKNOWLEDGEMENTS Deck Construction Momentum Technologies SR Roofing Products Outdoor Weathering and Testing Henry Company Momentum Technologies PRI Asphalt Technologies

52 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