ParsonsBrinckerhoffHalsall

Putting the R (Value) in Roofing

Putting the R(Value) in ofing

In This Presentation, We Will Cover:

• Brief History of Roof Insulation: The Rise of R Values• Insulation Properties• Insulation types:

– Characteristics– Advantages, Disadvantages and Challenges

• Regulations• The Future Rise of Insulation

Brief History of Roof Insulation

• 19th century, wood roofdecks

• Steep slopes to shed water• Early 1900s, evolution to

more diverse buildings• Architectural needs =

Structural Engineer solutions• Result of structural changes

= greater building designflexibility

The Advent of Low-Slope Roofing• Steel and concrete

revolutionized building design• Roof structures began to flatten

into low sloped roofs• Weight of concrete decks

limited designs• Introduction of lightweight deck

alternatives:– lightweight gypsum– fluted sheet metal decking

(most common)

The Advent of Low-Slope Roofing

The roofing membrane needed to be supported overthe spans of fluted sheet metal decks. Lowperformance insulation boards were introduced tomeet this need.These include:

• Wood Fibreboard• Perlite• Vermiculite• Glass fiber

The 1970s Energy Crisis• Over time, interior building climate needs and loads increased (air

conditioning and heating)

• OPEC oil embargo of the 1970s and energy crisis increased buildingoperating costs, forcing development of standards for buildings

• 1975: first version of ASHRAE model energy-efficiency standard forbuildings, Standard 90

• New insulations and solutions were introduced:– Phenolic foam– EPS– Polyisocyanurate– Lightweight insulated concrete– Spray Polyurethane foam

Insulation PropertiesPer CRCA, roof insulation needs to have:

• Dimensional stability;

• Firmness to withstand installation traffic (compressionstrength);

• Uniformity of thickness;

• Convenient, equal size panels;

• Shear strength; and

• Compatibility with other elements in the roof system.

Other Insulation PropertiesConsider also:

• Warping / cupping under field performance;

• Fire resistance / combustibility;

• Acoustical properties;

• Sustainability (manufacturing, field performance and beyond);and

• Stability of R value performance in different climates(temperature, humidity, etc.).

Conventional Roof Assembly• In conventional roof assemblies, the insulation is installed below the roof

membrane and can be exposed to different products and conditions whichmay be detrimental to them during the construction phase. Examples ofthese include:– Solvent based adhesive and primers– Hot mopping asphalt– High temperature from torches

• The type of insulation chosen must be able to resist these conditions or asuitable protection panel must be installed over the insulation beforeinstalling the membrane.

Inverted Roof Membrane Assembly (IRMA) orProtected Membrane Roofs (PMR)

• In an IRMA/PMR system, the insulation will always beexposed to water as the insulation is installed above theroof membrane.

• The insulation needs to have minimal water absorptioncharacteristics.

• The only type of insulation suitable for this is extrudedpolystyrene.

• Some hybrid roofs include insulation below the membraneand above the membrane

Insulation TypesCharacteristics, Advantages, Disadvantages and Challenges

• Wood Fibreboard• Perlite Board• Glass Fibre• Expanded Polystyrene• Extruded Polystyrene• Phenolic• Cellular Glass• Polyisocyanurate• Stone Wool• Spray Polyurethane Foam• Lightweight Insulating Concrete

Wood Fibreboard• Introduced in US markets in 1928

• Wood based product

• Interlocking cellulose fibersbonded together by heat,pressure and asphalt resin

• Boards limited to approximately25 mm thickness; thicker boardsglued together

Wood FibreboardSome Advantages:

• Economical

• Local manufacturing

• Relatively hard and can beused as an overlay board layerto protect the underlyinginsulation

• Available in tapered boards

Some Disadvantages:

• Low R-value per thickness

• Vulnerable to moisture

• Risk for mould (organicmaterial)

• Manufacturing process withhigh water contents = in-situroof membrane blistering

• Increased weight versus otherinsulation boards: ISO, EPS

Perlite Board• Introduced in US markets in

1958

• Composed primarily ofexpanded perlite withreinforcing cellulosic fibersand selected binders

• Mineral based insulation

• Top surface sealed with anasphalt emulsion coating

Perlite BoardSome Advantages:• Economical

• Stable R-value and fire resistance

• Can be used as an overlay boardlayer to protect the underlyinginsulation

• Dimensional stability

• Could contain high recycled content= environmental product

• High Density: install directly over awide flute or metal deck applicationfor spans up to 2½" and resistsdamage from construction andmaintenance

Some Disadvantages:• Fewer manufacturers

• Low R-value

• Can collapse and rot when wet,thus offering no moreprotection to the insulationbelow.

• Needs surface coating toprevent excessive absorption ofasphalt during the installationprocess

• Could contain high recycledcontent = unstable product?

Glass Fibre Insulation• Composed of inorganic glass fibers

• Used in commercial roofingsystems since 1941

• Surfaces faced with a glass fiberreinforced, asphalt kraft paper

Glass Fiber InsulationSome Advantages:• Stable R values

• Dimensionally stable

• Will not expand with heat or swellwhen exposed to moisture

• Flexible and chemically inert

• Flexibility will allow the insulationto conform to minor deckirregularities

• Thermal barrier over steel roofdecks: adds fire-resistance

• Can manufacture tapered panels

Some Disadvantages:• Not readily available

• Costs: production, handling

• Manufacturing and transport costs= less competitive than EPS / ISO

• Soft underfoot = impression of wetsubstrate = fools people

Expanded Polystyrene (EPS)

• Rigid closed cell foam plastic

• Formed from plastic polymer

• Moulded into blocks, processedinto sheets (flat or tapered)

• Types 1, 2 and 3 from less denseto denser materials.

Expanded Polystyrene (EPS)Some Advantages:• Lightweight

• No chemical blowing agents (CFC,HFC, HCFC) results in a more stableR value over time

• Very cost competitive versus otherboards

• Cut easily to suit site conditions

• Non-nutritive: It has no food valueand will not support the growth ofinsects, parasites or animal andplant life

• Inert to a wide range of chemicals

Some Disadvantages:• Will absorb water

• Vulnerable to petroleum products(solvents, adhesives, coatings,separation sheets, hot asphalt)which will soften and collapseboards

• Will shrink and warp whenexposed to high temperatures(75C+/170F+)

• Susceptible to foot traffic damageand damage during installation

• Combustible

Extruded Polystyrene (XPS)• Rigid Closed cell foam

• Low water permeability

• Low vapour permeability

• Known as type 4 insulation

• Can be made more dense to supportgreater weights for placement underplanters, high traffic areas etc.

Extruded Polystyrene (XPS)Some Advantages:• Resists water absorption =

Installation as part of a PMR/ IRMA roof assembly

• Low water permeability

• Low vapour permeability

• Can be made more dense tosupport greater weights(beneath planters, etc.)

Some Disadvantages:• Vulnerable to solvents, hot

asphalt, and hightemperatures (earlyinstallation underside BUR =major failures)

• Costs = limited use aboveroof membranes

• Use in PMR roofs requiresballast = system weight

Phenolic Foam• Manufactured from about

1974 to 1994

• Found in roofing systemssince 1982

• Catalyst blend of organicsulfonic acids

• Phenol is a weak acid that issoluble in water. It is the saltsthat remain after its reactionwith water that may promotemore rapid corrosion of thesteel deck or steelcomponents (fasteners andplates).

Phenolic Foam and CorrosionSome Advantages:• Highest initial R values

• Very cost competitive duringthe late 1980s, early 1990s.

• If dry and separated frommetal components, mayperform in the long term(vapour retarder over metaldecks / adhered vsmechanically fastenedsystems).

Some Disadvantages:• Increased risk of corrosion of metal

assembly components (white rust)

• Water can come into contact withphenolic foam (similar to otherinsulation) in a number of differentways:– Water is naturally entrapped in the foam– From leaks– From vapour entering the assembly

• Actual failures led to a phasing out ofthe product in the 1990s

• Important information when carryingout field testing

Cellular Glass Insulation

• Introduced in US marketsin 1943

• Manufactured fromcrushed glass and carbon

• Not common in Canada

Cellular Glass InsulationSome Advantages:• Impervious to moisture and water

• Vapor impermeable

• Fire protecting insulation: will not burnor give toxic fumes or smoke.

• Rot, insect, vermin and acid proof.

• Does not support the growth of mold,fungi or micro-organisms.

• Retains its original insulation value forthe life of the building.

• Can be made from recycling glass up to66% content = environmental product;May be a viable consideration for long-term environmental product

Some Disadvantages:• High Cost material and handling

• Brittle material may crack undermovement, shipping

• Limited manufacturer base

• Smaller panels 2’ x 4’ than otherinsulations = more joints = morehandling

• Relative low R value as compared toother commercial insulations

• Canadian contractor base unfamiliarwith technology, application andperformance

• Cold weather performance limitations

Polyisocyanurate• Closed cell polyisocyanurate

foam core bonded to paper,foil, or fiber glass reinforcedfacers

• Fabrication: Liquid foam issprayed against a substrate(paper facers, glass facers,foil facers) and expands toform a rigid panel

• Used in roofing since 1982

Polyisocyanurate (ISO)Some Advantages:• Cost competitive

(manuf./transport)

• Handling (lightweight)

• Installation (cutting)

• Higher R-values (typically around5.7, based on LTTR values)*

Some Disadvantages:• R-Value stability in the long term

= design to lesser R values(R5/inch per NRCA)

• Older insulations hadenvironmentally unfriendlyblowing agents (concern withroofs in place prior to 2000s,CFCs, pentenes, HCFC)

• Substrates originally consisted ofpaper facers (subject to moisturedamage, mould, curling), but nowinclude foil, glass or other facers

ASTM C1289 Standard Change• Standard for polyisocyanurate products

• Long-Term Thermal Resistance (LTTR) value:– 15-year weighted average of the thermal resistance

• Test method changed from CAN/ULC-S770-03 to CAN/ULC-S770-09 to better represent long-term thermal behaviour

• This change was effective as of January 1, 2014 andmanufacturers have consequently updated their literature

Stone Wool Insulation(Mineral Fibre)

• Production process: fusion ofvolcanic rock, slag and coke at atemperature of +-1600° C(2732°F).

• Minor amounts of binder and oiladded.

• Spinning process to produce massof fine, intertwined fibres

• Structure and density of the woolare adjusted before it enters thecuring oven

• Cured wool proceeds to cuttingsaws and packing equipment or ledto off-line equipment for specialtreatment

Some Advantages:• R-value long term stability

• Dimensionally stable

• Vapour permeable

• Noncombustible product with a meltingpoint of approximately 2150°F (1177°C)

• Excellent fire resistance properties

• Water repellent yet vapor permeablematerial.

Some Disadvantages:• Weight in comparison to other rigid

boards

• Soft underfoot: impression of wetsubstrate = fools people (densermaterials now on market)

• Cost. Some markets have highertransport costs

• Handling may cause irritation to skin

• Should not be exposed to weatherduring shipment, storage orinstallation

• Not intended for use as a structuralroof deck or for use under heavytraffic areas.

Stone Wool Insulation (Mineral Fibre Insulation)

Spray Polyurethane Foam Insulated roofs (SPF) or (PUF)

• Early 1970's, urethane foams werebeing specifically designed forroofing applications.

• Functions as both structuralinsulation and waterproofing

• Combination of chemicals sprayedon roof surfaces in layers to createmonolithic surface

• Opened and closed cellconfiguration

• Surface to be coated to protectfrom UV degradation

Some Advantages:• High fire resistance

•R-value long term stability

• Vapour permeable

Some Disadvantages:• Temperature, humiditylimitations for applicationmakes it difficult in someclimate zones

•Degradation of coverings

•Some coatings were foodsources for seagulls

Spray Polyurethane Foam Insulated roofs (SPF) or (PUF)

Lightweight Insulating Concrete• Roof installations prior to the 1970s

in varying thicknesses withoutintegral insulations

• Early 1970s, constant layers of EPSinsulation integrated in assembly.

• Late 1970s, stepped layers of EPSinsulation introduced.

• Different types of lightweightconcrete mixes provide ranges ofcompressive and tensile strengths tosuit project needs.

• System functions as both structuralinsulation and sloped to drain system

Lightweight Insulating ConcreteSome Advantages:• Durable claims

• Addresses ponding / poolingwater issues in existing roofs

• Air movement seals

• Replace membranes onlyover time = long term costsavings

Some Disadvantages:• Weight (installation and

ongoing): structutal review

• Cost

• Setup

• Limited applicators (betternow)

The R-Value• The R-value is an indication of the thermal

resistance of a material or assembly

• It can be represented as the thickness of amaterial divided by its thermal conductivity:

=Where

==

The R-Value• The R-value uses US units of (h*ft²*°F)/BTU

• The RSI value uses metric units of (K*m²)/W

• The R-values are roughly 5.67 times higher thanRSI values.

• U-value: overall thermal conductance. U-value isequal to the inverse of the sum of the R-value in asystem (U=1/R total).

The Rise of the R-ValueIndustry practices in most parts of Canada for some commercial,higher end buildings:

• Up to and including the 1960s: R-1 to R-5• 1970s: R-5 to R-10• 1980s: R-10 to R-15• 1990s: R-10 to R-20• 2000s: +- R-20• 2010s: +- R-20 (not following OBC codes)• 2020s: R-30 + ?• November 2007 RCI Interface magazine article by Jared Blum

outlines the various ASHRAE proposals up until that time.

R-Value/inch of different types of insulationApproximate Insulation Material R values per 1" thick boardsBased on room temperature values (colder and warmer conditions affect R values of different insulations)

Introduction in US Approx. R valuesRoof market ** (inch thickness)

Snow Roughly R–1Straw bales About R–1.5Vermiculite R-2.13Wood Fiberboard 1928** R-2.5** to R-2.78***Loose cellulose, fiber glass, rock wool R-2.5 to R-4Perlite 1958** R-2.78**Cellular Glass 1943** R-2.86** to 3.57Open-cell polyurethane spray foam R-3.6Moulded expanded polystyrene (EPS) low-density 1976** (1955**) R-3.85**

Dual density mineral wool board insulation R-3.8Expanded polystyrene EPS Type 1 R-3.75Rigid Glass Fiber (fiber glass) 1941** R-3.9 to R-4.2**

Stone Wool insulation (Mineral fibre)1937 (Europe)

1990s (US/Canada) R-4Lightweight Insulated Concrete (with EPS insulation) 1970s R-4Expanded polystyrene EPS Type 2 R-4.04Expanded polystyrene EPS Type 3 (High compressive strength) R-4.3Extruded polystyrene XPS Type 4 1965 R–5Spray polyurethane (closed cell) 1970s R–6Polyisocyanurate (ISO) Regular densities 1982** (1972**) R5.7 (R–5***)Polyisocyanurate (ISO) Higher densities R–5.7 plusPhenolic foam Rigid panel 1982** - end 1992 R–7 to 8.3**Aerogel 20xx? about R–10-30Vacuum insulated panels 20xx? R–45

Notes:*blown & in batts ** NRCA 1991 data(Canada soon after) *** NRCA recommended design R values for northernclimates

Other R values taken from various manufacturers published data or other sources

Which type of roof insulation to use?• It does not only depend on the roofing system being used

• Consider R value requirements for the building use and location

• R value requirements also vary per the OBC*.*2012 OBC code requirements for 2017 based on Energy Efficient DesignRequirements and on ASHRAE 90.1 standard or the Model National EnergyCode for Buildings (MNECB) plus supplementary standard SB-10 EnergyEfficiency Supplement July 1, 2011 update

• Requirements vary for new construction versus retrofit toexisting buildings and if building permits are required.

Which type of roof insulation to use?• Example Insulation Requirements (per SB-10 dated Sept. 14, 2012, in effect Jan. 1, 2014)

For a non-residential building within Part 9 scope in Ottawa, roof R-values will vary:

– New construction requirements:• Prior to 2014 (per SB-10 Aug. 15, 2006, in effect Dec. 31, 2014) = R- 22 insulation• Division 2 (permit application before January 1, 2017) = R-30 insulation• Division 3 (permit application after December 31, 2016) = R-30 insulation

– Roof replacement, no permit:• Replace with R-value to match or exceed existing per Division 11 (could be as low as R-5 !?)

– Roof replacement, permit required (not an Ottawa requirement now if project is purely roofreplacement):

• Considered as extensive renovation to meet parts of the building code (construct to meetstructural and fire-resistance compliance)

• GREY AREA: new roof system for roof replacement project needs to comply to fire-resistance and structural requirements, but no mention of meeting minimum R-values.Interpretation: Replace with R-value to match or exceed existing assembly per Division 11(could be as low as R-5 !? but assembly must be fire rated). Local Building Officials mayhave a different opinion.

Roof Insulation PerformanceThe Drifting R Value• Studies of insulation performance

• Paper presented by a Canadian consultant (RDH) at the 2013 RCI Building EnvelopeSymposium - Monitored Field Performance of Conventional Roofing Assemblies –Measuring the Benefit of Insulation Strategy (3 types of insulation assembliesversus 3 roof surface colours)

• Publication by BSC (U.S. Consultants): Information Sheet 502- Understanding theTemperature Dependence of R-values for Polyisocyanurate Roof Insulation

•Similar conclusions from research• Various types of insulations perform differently at different exterior temperatures,

with minimal impact from roof surface colour (cold weather performanceconcerns)

• Using more stable insulations or hybrid insulation systems (different insulationtypes) with more stable insulation layers on top will provide more consistentresults

Roof Insulations are Only as Good as Their Application

• It takes more than just insulationto slow heat

• Importance of air and vapourretarder substrates and detailing

• Insulation will not work in awind tunnel

– Still air is about R-6 per inch.– Eliminate Gaps in insulation boards

(horizontally and vertically)

Case Study- "Consolidation" of EPS insulation

towards low point.- 1.5" gap created along the perimeter- Thermal loss and ineffective insulation

Installation Challenges- Are Fastening patterns

ever followed?- Are insulation joints

staggered?- Does it matter?

Laying insulation on metal deck, offset joints horizontally and vertically

Roof Insulation Performance

Roof Insulation Performance

Gaps in phenolic insulation underside membrane, causing ridges to form above

Metal roof on an industrial building:Heat loss due to inadequate insulationbetween roof girts and metal roofcladding.

Roof Insulation Performance

Inverted roof on an office building:Heat loss through insulation board joints.

The Future of Roof Insulation

Where is the market heading?

The Future of Roof Insulation

Climate change impact on roofing and insulation requirements

The Future of Roof InsulationGOVERNMENTS WILL CONTINUE TO BE INVOLVED

• Regulations for thermal performance of buildings will driveinsulation development and costs (already has)

• Programs and Incentives Designed to Help Battle ClimateChange (Politicians react to climate change)

• Other regulations affecting insulation– Safety: mechanically fastening through decks and conduits!– Health: Will insulation types or adhesives used today be a

health risk tomorrow? (past history confirms this!)

The Future of Roof Insulation• Consultants have a responsibility in insulation selection

for sustainability– Design to leave substrates in place, where practical– Consider building airtightness in designs– Consider designs of roofs that harvest energy– Design to provide optimal system performance– Design to provide long term health, safety, cost benefits– Consider actual Thermal Performance of in-situ insulations. Are

they equal to claims made?– Work with all parties in the construction team and provide the

needed Quality Assurance during all stages of roof systeminstallation

– Provide knowledgeable services (RCI Registered RoofConsultants – RRCs and Registered Roof Observers – RROs)

The Future of Roof Insulation• Will insulation be thicker or thinner?

New products and innovations• Vacuum Insulated Panel (VIP)

– Highest R values to date: R-30 to R-50 per inch = thinner systems =construction cost savings

– Germany / Europe innovation– Cost now prohibitive and production challenges: sealed units cannot

be cut (getting around this)– NRC Research - Long-term performance of Vacuum Insulation Panels

(VIP) in the Canadian climate Volume 17, Number 3, September 2012

NRC Research• Research Paper: Long-term performance of Vacuum Insulation Panels (VIP) in the

Canadian climate Volume 17, Number 3, September 2012• Research Paper presented at the IVIS Symposium: APPLICATION OF VACCUM

INSULATION PANELS IN LOW SLOPE ADHESIVE APPLIED ROOFING SYSTEMS

The Future of Roof InsulationSilica Aerogel (Maerogel):• Aerogel is almost a

product out of sciencefiction. Nicknamed“frozen smoke”

• R-10/inch

• Aerogel provides nearly40 times the performanceof fiberglass insulationResearcher: Prof. Dr. Halimaton Hamdan

Malaysia

Conclusion• The selection of insulation types varies with building use, building code

interpretations, building location

• R-values drive the selection process (maybe too much), need to considerother properties as well as installation challenges

• Long-term thermal performance and in-situ stability are a concern thatcannot be ignored

• Multiple insulation layers create redundancy and deal with air movement,thermal bridging

• Multiple types of insulation within an assembly can deal with variancesand optimize total system performance

• More research is leading to better existing insulations and newgenerations of “science fiction” insulations

• Maybe thinner will be the new normal, not thicker!

Putting the R(Value) in ofing

Thank You