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Learn about the benefits and properties of polyisocyanurate (polyiso) insulation for constructing energy-efficient buildings. This program is registered with the AIA/CES for continuing professional education.
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Polyisocyanurate (polyiso) insulation for commercial exterior wall assemblies Date & Place
Carlisle, Inc. 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. 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. Thank you!
Energy Use in the Built Environment • The commercial real estate industry spends approximately $24 billion annually on energy. • Energy represents the single largest controllable operating expense for office buildings - typically a third of variable expenses • Source: www.boma.orgBEEP (BOMA Energy Efficiency Program) U.S. ENERGY USE BY SECTOR
The Importance of Good Insulation • Government and private initiatives call for aggressive reduction of energy consumption • High-performance insulation is crucial for achievement of these objectives! Today we will learn about polyiso insulation – a commercially-available, cost-effective material that easily enables construction of more energy-efficient buildings.
Learning Objectives • List the basic characteristics and important physical properties of polyiso foam board insulation. • Describe the track record and market adoption of polyiso insulation in building construction applications. • Explain the benefits afforded by polyiso insulation when used in exterior wall assemblies. • List the important elements of successful installation of polyiso insulation in exterior wall assemblies.
Chemistry. • How it’s made. • Properties – Polyiso Spec ASTM C 1289 • R-Value Learning Objective 1: List the basic characteristics and important physical properties of polyiso insulation.
Polyiso Foam • Similar to polyurethane • Starts as pourable resin. 2-component rapid reaction causes expansion and cure • Forms a rigid plastic, closed-cell foam • In production, reaction occurs in-line, while facers are laminated on both sides to form boards. Boards are cut to size, packaged, cured and shipped Beads of mixed 2-part resin extruded onto facer Resin expands and cures, filing space between facers
Polyiso– Green Features • No CFCs, zero ozone depletion potential (ODP) • EPA compliant blowing agents • Recyclable through re-use or down-cycling • FSC-Certified wood used on wood-faced products • Durable, long service life material • National manufacturing network - available regionally
Polyiso Insulation Properties • ASTM C 1289 “Standard Specification for Faced Rigid Cellular Polyisocyanurate Thermal Insulation Board” • Classification: Facer composition, foam core compressive strength • Physical Properties: Dimensional stability, flexural strength, water absorption, water vapor transmission • R-Value • Measure of heat flow through specimen • Test methods dictated in ASTM C 1289
Polyiso Insulation Facers facer • Most roofing applications use glass-reinforced organic felt facers • Polyiso for wall assemblies has coated-glass or foil facer • Coated-glass facers improved fire resistance, moisture resistance and dimensional stability • Foil facers improve fire resistance, UV resistance, moisture resistance and R-Value • Polyiso can be easily laminated to plywood or OSB to form an insulating nail base polyiso foam core facer
R-Value – The Key Property of Insulation R Value of common building materials R-value of insulation comes primarily from air or some other gas R value is a material property indicating resistance to heat flow though the material. Insulating materials have higher R-Value.
How Insulation Provides R-Value • Foam: Cells are filled with air or other gas • Fiber: Air is trapped among the fibers FIBER FOAM
Foam vs. Fiber Insulation FIBER FOAM • Plastic Based (combustible) • Board foam or spray foam • Closed Cell or Open Cell • Closed cell type is an air barrier • Closed cell type resists water absorption • Mineral Based (non-combustible) • Semi-rigid boards, batts or loose (blown-in) • Permeable to air and moisture
How do Foam Insulations Provide Such High R-value? • Foam insulation consist of plastic resin and gas • Cells in polyiso insulation are filled with a higher-R-value gas than air Most common blowing agent used in polyiso and polystyrene foam insulation CFC, banned for use in insulation production
How does Polyiso Compare with other Foam Board Insulations? * Based on 2” thick board, R-14.4 foil-faced polyiso Note: all 3 insulation types are suitable for exterior wall applications. The check mark indicates the insulation that is best in that characteristic.
Learning Objective 2: Describe the track record and market adoption of polyiso insulation in building construction applications.
Polyiso History • Derived from polyurethane chemistry, which first appeared in the 1950s • Polyiso foam insulation for construction first appeared on the US market in the late 1970s • Polyisocyanurate Manufacturers Association (PIMA) established in 1988 • More than 70% of all roof insulation used in the USA is polyiso • Growing use in exterior wall assemblies Polyiso directly over steel roof deck Polyiso in a wall assembly
Polyiso Use - Construction • Polyiso has high service temp – up to 250°F • Unaffected by most solvent-based adhesives and coatings • Thermoset plastic – performs well in roof and wall assembly fire testing • High R-value per inch allows thinner board Wall Roof
Polyiso Heat Resistance and Dimensional Stability • Heat Resistance • Polyiso service temp up to 250°F • Can be installed directly under metal and under roofing membrane • Dimensional Stability • Won’t shrink or warp with heat and humidity. Polyiso boards directly under black roof membrane
Polyiso Moisture Resistance • ASTM C 209, 2h room-temp water immersion, <0.1% volume • Closed cell polyiso foam resists moisture absorption from ambient humidity • Moisture-resistant facers, such as foil and coated glass greatly enhance performance • Polyiso is suitable for use in above-grade exterior wall assemblies and in covered roof assemblies. Behind wall cladding Under roof membrane
PolyisoR-Value Measurements • Felt-Faced Roofing Insulation • CAN-ULC S770 Long-Term Thermal Resistance (LTTR) • R-5.6 to 6.0 per inch • Wall Insulation ASTM C 518 • 75°F mean temp • ASTM C 1289 requires 180 day aging at room temp and minimum 40°F temp difference • R-6.0 to 6.7 per inch Coated-glass-faced Foil-faced
“Continuous insulation” in building code • High R-value per Inch • Heat & moisture management • Air & vapor barrier • Fire performance Learning Objective 3: Explain the benefits polyisoinsulation affords when used in exterior wall assemblies.
The Colder the Climate, the more Insulation is Required • USDOE Heating Zones • 8 in the USA • 1 is warmest, 8 is coldest
Component R-Value vs. Assembly U-Value Material 1 Material 3 Material 4 Material 2 • Building Code Gives 2 Compliance Options: • Meet a minimum R value of insulation prescribed for that type of assembly • Meet a maximum assembly U Value designated for that type of assembly = R1+R2+R3+R4 RAssembly 1 UAssembly = R1+R2+R3+R4 R1 R2 R3 R4
Requirements for “ci” • Example: IECC 2012 Steel Stud Wall Requirements • R-13 + 7.5 ci R-13 in the stud cavity Stud Cavity Insulation Continuous Insulation “ci” is insulation installed continuously across studs. R-7.5 minimum “continuous insulation”
Energy Loss Through Insulation Discontinuity Batt insulation installed between steel studs IR camera image showing thermal bridging
Continuous Insulation Requirement Insulation placed between studs loses much of its nominal R-Value Source: ASHRAE 90.1, 90.2
Example – IECC Requirements for “ci”, Non-Residential Steel Stud walls 5 5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 3.8 3.8 3.8 NR NR NR NR NR ‘06 ‘06 ‘06 ‘06 ‘06 ‘06 ‘06 ‘06 ‘09 ‘09 ‘09 ‘09 ‘09 ‘09 ‘09 ‘09 ‘12 ‘12 ‘12 ‘12 ‘12 ‘12 ‘12 ‘12 Min R-value of ci required NR Zone 1 Zone 2 Zone 3 Zone 4 (Exc. Marine) Zone 6 Zone 5 & Marine 4 IECC version 7.5 7.5 Zone 8 Zone 7
Common Types of “ci” • Polyiso • XPS • EPS • SPF • Rockwool
R-Value of Common Types of Insulation • Polyiso has the Highest R-Value per Inch • Use thinner board to comply with minimum code requirements • Use same size board and put more R-value into limited wall space
Benefits of Thinner Insulation • Reduced cost of insulation • Simplify and reduce cost of cladding attachment • Shorter fasteners • Larger spacing • More cladding options
1 1 2 2 Example: Polyiso vs. XPS 5 4 3 5 4 3 7 • On 10,000 SQ FT of wall, what is the difference in heat loss through the wall, given a ΔT of 30°F? • XPS Wall: 16,216 BTU/h; POLYISO Wall: 12,300 BTU/h • POLYISO wall presents a 24% improvement 7 6 6 6 2” Foil-Faced POLYISO R-14.4 2” XPS R-10
“ci” on the Exterior Keeps walls Drier during Winter Wall is dry where insulation is installed on the exterior Condensation of interior moisture on cold block Indoor moisture condenses on cold steel studs and gypsum sheathing. Vapor retarder traps this moisture.
“ci” and Air/Vapor Barrier Membrane work Together • Air/vapor barrier prevents air and moisture transmission through wall, even seals around fasteners • “ci” keeps steel studs, gypsum sheathing and stud cavity above dew point, preventing condensation Steel studs and insulation Continuous insulation (ci) installed over air/vapor barrier Gypsum sheathing Fully-adhered air/vapor barrier membrane on gypsum sheathing Exterior cladding fastened to structure
Polyiso Board Can be Installed as an Air and Vapor Barrier FOIL-FACED POLYISO, FOAM SEALANT BETWEEN BOARDS • Vapor Barrier (ASTM E 96): • 1” board has < 1 Perm w/ coated glass facer, <0.1 Perm with foil facer • Air Barrier (ASTM E 2178): • 2010 ASHRAE 90.1 and 2012 IECC qualify minimum ½” thickness foil-faced as an “air barrier” POLYISO INSULATION AIR/VAPOR BARRIER – BRICK CAVITY WALL Reduced cost assembly, but less redundancy than wall with membrane + “ci”
NFPA 285 • 2-story wall assembly burn test • Applicable to Type I-IV Construction • Simulates an interior fire, with flashover effect through window opening. • Vertical and lateral fire propagation is evaluated. • Insulation, cladding and wall membranes can trigger Code Requirement!
NFPA 285 Test Set-Up 1st: burn room burner is ignited 2nd after 5 min, window burner is ignited 3rd after 30 minutes, both burners are shut off. 4th residual burning is allowed to progress for at least 10 minutes Thermocouples here cannot reach 1,000 deg F Test Wall 7’ 6” min. 10’ 18’ Burn room burner 7’ 6” min. Window burner Section View – not drawn to scale
EXTERIOR: Fire propagation not to occur beyond area of flame plume impingment CORE: Fire propagation within the wall is allowed only a certain distance above window opening, indicated by thermocouples INTERIOR: Temp not to exceed 750 F in 1st story stud cavity and flames shall not reach second story. NFPA 285 Acceptance Criteria insulation cladding stud • Measures lateral and vertical propagation of fire • Pass/fail determined by amount and layering of combustible components. • Mineral wool fire stopping required in stud cavity between floors interior finish Sheathing Air barrier Air space
NFPA 285 Pass – what does it mean? Assembly test includes… • Base Wall System • Approved Exterior Finish • Insulation Material Options • Floor line Fire-stopping • Stud Cavity • Exterior Sheathing • WRB Membrane
Polyiso Performs well in Vertical Burn!! NFPA 285 test, in progress and inspection after burn • Inspection • Polyiso stays in place • No formation of burning drips • Protects underlying rubberized asphalt membrane
PolyisoPasses the NFPA 285 Test with Many Types of Claddings Projects showing polyiso insulation and aluminum compsite (ACM) rain screen cladding
Class A Polyiso Passes NFPA 285 Even When Applied Over Open Studs • Install air, water, vapor and thermal barrier in one layer • Build a high-performance wall at a reduced cost!
Polyiso Allows Simple Window Details in the NFPA 285 Test • Polyiso passes NFPA 285 without any fire blocking in window opening! XPS NFPA 285 Window Detail: Specifies Mineral Wool Pinned across Window Head
Other Fire Tests ASTM E 84 • ASTM E 84 • “Tunnel Test”: horizontal burn of material • Limited applicability to vertical wall performance. • Standard Polyiso: flame spread 75 or less, smoke 450 or less • “Class A” Polyiso: flame spread 25 or less and smoke 450 or less • NFPA 286 • Corner burn test • Some polyiso foam/facer configurations can pass this test • Required if insulation will be left exposed in interior wall and ceiling applications NFPA 286
Details and Instructions • Qualified installer • Field quality control • Reliable supplier Learning Objective 4: List the important elements of successful installation of polyiso insulation in exterior wall assemblies.
Insulation Manufacturer shall Provide Standard Details • Windows • Foundation • Penetrations • Wall-to-Roof • Inter-Story • Corners • Expansion joints • Termination at existing
Barriers Shown in Details Shall Align Thermal image showing alignment of wall insulation with window’s thermal break • Thermal barrier • Air barrier • Water resistive barrier
Installation Instructions • Board pattern • Joint treatment • Fastening • Bonding • Exposure and Protection