The Evolution of Roofing
1
Helene Hardy PierceGAF
Discuss both low- and steep- pitch roof solutions for hot-humid climates and high-velocity hurricane zones, review evolution of roofing methods and materials, new vs. replacement roofs.
So let’s talk about roofing membranes…
The Roofing System…
Membrane
System Wind/Fire Traffic Bldg. Use Access Secondary Use Maintenance
Structural Deck… Deck
Ability to attach Moisture Movement Slope Movement
relative to walls Air leakage
Insulation…
Insulation Number of layers Attachment Compatibility Fastener location Durability to traffic Coverboard or not Joints staggered
Membrane… System Type
Mechanically attached Hot asphalt Heat welding Fully adhered
Membrane Number of layers Type
Vapor Retarder Need Type Attachment Compatibility
Details
Critical to ANY Installation…
WHERE DID WE COME FROM?Evolution…
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From Tar Pits to TPO…
BUR
Indians would use surface bitumen to waterproof…
From 1896…
Bitumen…
– Pitch– Asphalt
• Type I Dead Level Applications• Type II• Type III• Type IV Steep Slope Applications
2/12+– Rubberized
Plies…
• Type IV Fiberglass• Type VI Fiberglass• Fiberglass Reinforced• Polyester Reinforced
CARE Sponsored by: NRCA Members
Surfacing…
• Protection– UV Degradation– Roof Top Traffic– Wind Damage
• Aggregate• Mineral Surface (Granulated)• Coating
• Multi-ply• Waterproofing • Surfacing Options
BENEFITS
• Multi-ply• Waterproofing • Surfacing Options
BENEFITS
• Labor • Fumes• Temperature
LIMITATIONS
• Multi-ply• Waterproofing • Surfacing Options
BENEFITS
• Labor • Fumes• Temperature
LIMITATIONS
• “Old Technology”• Not Energy Star/Reflective• No Longer Available
MISPERCEPTIONS
From Tar Pits to TPO…
BUR
EPDM
EPDM…
• Since 1960’s• Went down quickly-large panels• Very economical-gravel ballast• More versatile-building movement• “Cleaner” than BUR
• Very Stable Membrane• Large Sheet Size• Taped Seams Perform Well
BENEFITS
LIMITATIONS
MISPERCEPTIONS
• Very Stable Membrane• Large Sheet Size• Taped Seams Perform Well
BENEFITS
• Low Reflectivity• Taped/Glued Seam vs. Heat
Fused/Welded• “Single Ply”
LIMITATIONS
MISPERCEPTIONS
• Very Stable Membrane• Large Sheet Size• Taped Seams Perform Well
BENEFITS
• Low Reflectivity• Taped/Glued Seam vs. Heat
Fused/Welded• “Single Ply”
LIMITATIONS
• Most Are Ballasted• Black Energy Efficient• Not Puncture Resistant
MISPERCEPTIONS
From Tar Pits to TPO…
BUR
EPDM
PVC
PVC…
• Introduced in early 1970’s• Heat welded seams• Highly reflective - white • Very chemical resistant• High fire resistance
• Reflective• Heat Welded Seams• Chemical Resistance
BENEFITS
LIMITATIONS
MISPERCEPTIONS
• Reflective• Heat Welded Seams• Chemical Resistance
BENEFITS
• “Red Listed” by some• High Temperature • Single Ply
LIMITATIONS
MISPERCEPTIONS
• Reflective• Heat Welded Seams• Chemical Resistance
BENEFITS
• “Red Listed” by some• High Temperature • Single Ply
LIMITATIONS
• Shatters• Shrinkage• Impact Resistance
MISPERCEPTIONS
From Tar Pits to TPO…
BUR
EPDM
PVC
Modified Bitumen
Polymer Modified Bitumen…
Mod
ified
Bitu
menAPP
SBS
APP...• Atactic Polypropylene • Developed in Italy, introduced to US in late 70’s• Excellent inherent flexibility and stability• Heat ( Torch ) Applied
SBS...• Styrene Butadiene Styrene• Developed in Northern Europe• Excellent flexibility and elongation
characteristics• Hot Applied• Cold Applied• Torch Applied• Self Adhered Applied
• Multi-ply• High Abuse/Puncture • Easy Repair/Maintenance
BENEFITS
LIMITATIONS
MISPERCEPTIONS
• Multi-ply• High Abuse/Puncture • Easy Repair/Maintenance
BENEFITS
• Labor • Open Flames (APP)• Cost
LIMITATIONS
MISPERCEPTIONS
• Multi-ply• High Abuse/Puncture • Easy Repair/Maintenance
BENEFITS
• Labor • Open Flames (APP)• Cost
LIMITATIONS
• “Old Technology”• Not Energy Star/Reflective• Durability in High UV
MISPERCEPTIONS
From Tar Pits to TPO…
BUR
EPDM
PVC
Modified Bitumen
TPO
TPO…
• Introduced in late 1980’s• Heat welded seams• Highly reflective - white • Cost effective• High UV/heat formulations
• Reflective• Heat Welded Seams• Cost
BENEFITS
LIMITATIONS
MISPERCEPTIONS
• Reflective• Heat Welded Seams• Cost
BENEFITS
• Chemicals• Weather - Adhered• Single Ply
LIMITATIONS
MISPERCEPTIONS
• Reflective• Heat Welded Seams• Cost
BENEFITS
• Chemicals• Weather - Adhered• Single Ply
LIMITATIONS
• Length on Market• Performance• Impact Resistance
MISPERCEPTIONS
From Tar Pits to TPO…
BUR
EPDM
PVC
Modified Bitumen
TPO
Installation Evolution…Primarily Single Ply Membranes…
Not As Simple As a Few Years Ago…
2000
Today
BallastedFully Adhered
Mechanically Attached
Mechanically AttachedFully Adhered*
BallastedRhinoBond Attachment
Self Adhered
Mechanically Attached Ballasted
Fully Adhered• Solvent Based• Low VOC• Water Based• Low Rise Foam• 2 Part
RhinoBondSystem Self-Adhered
Installation Methods
Mechanically Attached• Cost effective• Most common installation method• No sprayers or additional capital
investment• No odors• Up to 50% faster installation than fully
adhered smooth membranes• Membrane carries wind load• Wide application temperature
Mechanically AttachedLimitations/Considerations
• Deck type/holding power • Insulation thickness• Tapered insulation difficulty*• Impact resistance• Need for an air barrier• Moisture• Roof as a platform
* Note: tapered with any mechanical attachment increases difficulty
Ballasted
• Low labor cost• No sprayers or additional capital
investment• No odors• Ballast provides wind resistance• Minimal fastening required• Ideal for very wide sheets• High impact resistance
BallastedLimitations/Considerations
• Deck type – capacity for load • Availability of quality ballast• Leak detection• Wind resistance – code restrictions• Roof as a platform
Fully Adhered – Bonding Adhesive
• No sprayers or additional capital investment
• Excellent wind uplift performance• Familiarity with workers• Solvent, low VOC, and water based
adhesives• Uniform, smooth appearance• Ability to “bury” fasteners
Fully Adhered – Bonding AdhesiveLimitations/Considerations• VOC content of adhesive• Weather limitations for both application
AND storage• Open time – largest installation time• Material costs• Wet decks and adhesives don’t play well
Fully Adhered – Fleece-Back Laid in Wet
• Fast installation time – low labor cost
• Excellent wind uplift performance• Low odor/VOC compliant• No open cure times• Uniform, smooth appearance• Ability to “bury” fasteners• Excellent impact resistance
Fully Adhered – Fleece-Back Laid in WetLimitations/Considerations
• Material costs• Wet decks and adhesives don’t
play well • Substrates• Cure times
Fully Adhered – Low Rise Foam & 2 Part Adhesives
• Fast installation time – low labor cost
• Excellent wind uplift performance• Low odor• VOC compliant• Uniform, smooth appearance• Ability to “bury” fasteners• Excellent impact resistance
Fully Adhered – Low Rise Foam & 2 Part AdhesivesLimitations/Considerations
• Depending on adhesive, equipment cost can be high
• Material costs• Wet decks and adhesives don’t
play well • Substrates
Rhinobond System
• Moderate material cost• No open cure times• No need for half sheets at
perimeter and corners• Less flutter than MA systems• Less fatigue on fasteners• Wide application temperature
Rhinobond SystemLimitations/Considerations• Equipment cost (however, can
increase speed with second machine)
• Deck type/holding power • Tapered insulation difficulty• Impact resistance• Need for an air barrier?• Moisture• Roof as a platform
Self-Adhered
• No sprayers or additional capital investment
• Excellent wind uplift performance
• No odors/no adhesives• No open cure times• Ability to “bury” fasteners
Self-AdheredLimitations/Considerations
• Material cost• Single layer of insulation• Self-adhered lap vs. heat
welded lap• Aesthetics
Market Evolution…
Technology Transition
Technology Transition… digging a little deeper
P&S
REGARDLESS OF MEMBRANE, Still Need Good Bones!!!
Don’t Forget the “20 Questions!”
• Identify the poison pills• Rule out what won’t work• Drill down to better options
These questions should identify WHAT won’t work, WHAT will work, and WHAT are the best options for the specific property… and WHY, based on the needs of the building owner
Roofing System ChecklistCost Low labor cost Low capital investment Cost effective Speed of installation
Performance High impact resistance Redundancy Wind resistance High reflectivity Fire resistance @ slope
System Traits Fully adhered Uniform appearance Ability to bury fasteners No open cure time VOC compliant Low or no flutter Low odor No open flames Wide application window Traffic resistant Maintainable
Roofing System ChecklistCost Low labor cost Low capital investment Cost effective Speed of installationPerformance High impact resistance Redundancy Wind resistance High reflectivity Fire resistance @ slope
System Traits Fully adhered Uniform appearance Ability to bury fasteners No open cure time VOC compliant Low or no flutter Low odor No open flames Wide application window Traffic resistant Maintainable
SE SpecificWindAmbient ConditionsEnergy CodeDirt/algae Pick-UpPhasingDeck PreferencesRadiative Properties
PART IV: Theory Is Nice…But Let’s Look at Reality
Real World…Specifics…
• New Construction• Concrete Deck• Iso Insulation
What Comes to Mind • What is concrete poured
over?• Concrete = Adhered• Is the deck flat?• What kind of “concrete”?
• Probably Not • Perhaps • Better/Best
Cost to fasten into concrete
Time
Tapered Insulation?
Vapor Retarder -
Access
Owner Preference
Wind Limitations
Availability of Ballast
Attachment Ease
Wind Uplift
Vapor Retarder +
Think Water
Real World
Specifics• Existing Standing
Seam Metal Deck• Want to Add
Insulation
What Comes to Mind• Attachment to what?• Wind Performance• Fire Performance• This is NOT a
traditional 22 gauge metal deck
Highlights… Retrofit Over Metal
• Retrofit – means existing metal building may well have been built with earlier/different strength limits
• Deflection limits for total load of L/60, whereas for membrane roofing “deck deflection should be no more than L/240 (4 times less deflection allowed)
Highlights… Retrofit Over Metal• Retrofit – means existing metal building may well have
been built with earlier/different strength limits
• Deflection limits for total load of L/60, whereas for membrane roofing “deck deflection should be no more than L/240 (4 times less deflection allowed)
• Most existing wind uplift ratings based on 22 gauge or thicker metal deck with 33 or 80 ksi yield strength
• FM 1-31 on Panel Roof Systems may be a good source of recommendations
(Probably) Not Perhaps Better
Weight - ballasted
Deflection for fully adhered
Into secondary support structure
Only with structural evaluation
Only into secondary support structure
Only with structural evaluation
Real World…
Specifics• Metal Deck• Replace due to
Blow Off• 85’ Building Height
What Comes to Mind• Wind performance• Parapet walls?• Type of steel deck?• Exposure – C or D?
(Probably) Not Best SolutionIt’s all about wind performance…
Check out FM Data Sheets…don’t think you can get there!
Well attached insulation + fully adhered membrane
Real World…
What Comes to Mind• Type of solar system• Roof area to be
covered?• Age of existing roof?• Ability to perform
maintenance?• Impact resistance?
Specifics• Roof as a
Platform• Solar
So let’s talk about steep slope roofing …
Age of Roof at Time of Remodeling Project, Homeowner Survey
90
n=559
The State of the Roofing Industry…• Top 5 complaint industry to the BBB• Over 50% of contractors go out of
business within 5 years• Millions of dollars wasted• Owners distrustful • Some bad contractors
Tear Off…Expose existing or
potential problems• Rotted decks• Mold growth• Damaged framing • Missing
underlayments• Flashing system
deteriorated
Components of a Steep Slope Roof
1. Shingles/seal tabs/4 or 6 nails
2. Underlayment3. Self-adhered
underlayment/ice dam protection
4. Starter strip/rake edge
5. Ventilation, balanced
6. Hip/ridge products
93
Leak Barriers
Leak Barriers
Ventilation…
Federal Housing Administration…
1. 9/10 homes are not properly ventilated
2. 1/300 Net Free Ventilated Area Ratio
3. Ventilation System must be balanced
Inadequate Ventilation…
• Mold• High energy consumption• Premature material wear• Rotted decks
Ventilation…
Non Vented...90° Outside170° Rooftop140°-165° Attic
Ventilation…
Vented...90° Outside170° Rooftop120°-135° Attic
Ventilate for Longevity
100
For every 10C increase, activation energy doubles.(Arrhenius Equation)
Georgia Tech…Ridge and soffit vents are best ventilation source
US Dept. Of Housing…Proper venting prevents ice dams
Plywood Associations…Proper ventilation is required for decking
Shingle Manufacturers…Ventilation is required for warranties
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107
Asphalt Shingles…
Today’s Asphalt Shingles
Wide Range of Styles and ColorsAffordableEasy to MaintainLightweightEasy to InstallTitle 24 Options/Cool Roofing Options
Asphalt Shingles…Historically Speaking
1980 2017
LaminateShinglesStripShingles
80% 80+%
• Shed Water• Fire Resistant• Durable• Wind Resistant• Code Compliant
Asphalt Shingles…Regardless of Style or Color
Wind TestingCan Be Either D7158 or D3161
Wind speed ASTM D7158 ASTM D316160 mph -- Class A90 mph Class D Class D110 mph -- Class F120 mph Class G --150 mph Class H --
Comparison of ASTM D7158 and ASTM D3161:
Documentation of Code Compliance
Third-party certification:
Wind Driven Rain Test Summary…
Florida Building Code Test Protocol TAS-100
Minimum slope specified by the manufacturer
No water infiltration through the sheathing; no blow-off/tear-off or release of the shingle or portion thereof
15 min wind/water
10 min off
35, 70, 90, & 110 mph
8”/hour rain event
Wind Driven Rain Test Summary…
Wind Driven Rain Test
www.ricowi.com
Questions?
Thank you for your time and attention!