BELOW GRADE ASSEMBLIES AND RIGID INSULATION 2010 Atlas Roofing Corporation. Atlas EPS is a division of Atlas Roofing. ThermalStar is a registered trademark and X-Grade is a trademark of Atlas Roofing Corporation.
Atlas Roofing is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES). Credit(s) earned on completion of this program will be reported to AIA/CES for AIA members. Certificates of Completion for both AIA members and non-aia members are available upon request. This program is registered with 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.
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LEARNING OBJECTIVES Learning objective 1: at the end of this program, participants will be able to describe the components of a well designed below grade assembly. Learning objective 2: at the end of this program, participants will have acquired knowledge in the benefits that can be gained by using the correct details below grade. Learning objective 3: at the end of this program, participants will have acquired knowledge of the types of rigid insulation available and their unique attributes. Learning objective 4: at the end of this program, participants will understand facts regarding sustainability of the various types of rigid insulation.
Learning objective 1: at the end of this program, participants will be able to describe the components of a well designed below grade water management assembly.
BELOW GRADE ASSEMBLIES
TYPICAL COMPONENTS OF A BELOW GRADE WATER MANAGEMENT SYSTEM Drainage materials Filter fabrics Damp-proofing or waterproofing membranes Protection board/insulation materials Drainage tile
BELOW GRADE COMPONENTS RIGID INSULATION DRAINAGE MATERIAL WATERPROOFING MEMBRANE FILTER FABRIC DRAIN TILE
Learning objective 2: at the end of this program, participants will have acquired knowledge in the benefits that can be gained by using the correct details below grade.
Why is it important to detail below grade assemblies correctly? To moderate interior temperature To maintain good indoor air quality Eliminate mold and moisture issues Reduce energy consumption Increase building durability Reduce greenhouse gas emissions
Energy loss below grade, greenhouse gas emissions
Learning objective 3: at the end of this program, participants will have acquired knowledge of the types of rigid insulation available and their unique attributes
RIGID INSULATION TYPES POLYISOCYANURATE - POLYISO EXTRUDED POLYSTYRENE - XPS EXPANDED POLYSTYRENE ARCHITECTURAL GRADE EPS-A EXPANDED POLYSTYRENE - COMMODITY GRADE EPS-C
R VALUE PER INCH OF EACH TYPE OF RIGID INSULATION 7 6 5 4 3 2 1 R-values per inch 0 Polyiso XPS EPS - A EPS - C
CELL STRUCTURE
CELL STRUCTURE
CELL STRUCTURE Conclusion: Open cell or closed cell does not have a basis in lab testing EPS and XPS have virtually the same cell structure Some other types of rigid insulation do have a cell structure that appears more open when viewed with a microscope Contrary to what might be inferred from the discussion of open cell and closed cell structure, all rigid insulation material will absorb water if installed without proper drainage.
COMPRESSIVE RESISTANCE
COMPRESSIVE RESISTANCE 120 Available compressive strength by type 100 80 60 40 20 0 Polyiso XPS EPS - A EPS - C
BLOWING AGENTS
BLOWING AGENTS What are the gasses contained in XPS and Polyiso? Since 2010, manufactures have had to phase out HCFC blowing agents as a result of the Montreal Protocol. Polyiso and XPS producers use gasses in their formulations to create the insulating cells, and these trapped gasses impede heat transfer, leading to higher initial R-Value per inch. EPS contains only air in the insulating cells. Although the exact formulas are proprietary, here are some facts about the gasses in XPS and Polyiso. Since 2010, XPS has reportedly been produced using a refrigerant know as R134a as the basis for the blowing agent in XPS. This substance is a greenhouse gas more on this later. The gasses used in Polyiso production are not published but they may also be greenhouse gasses.
BLOWING AGENTS Ultimately, some gas in XPS and Polyiso escapes the cells. These emissions are not desired in construction products since it makes heating and cooling design difficult. As previously mentioned, since EPS-A and EPS-C contain only air, the thermal performance is stable from the moment installed to end of life, allowing predictable thermal design. Much of the historical data on both Polyiso and XPS long term performance is based on now discontinued gasses. EPS-A and EPS-C contains only air in its insulating cells, just as EPS has contained since its creation in the 1960s As gas escapes, the thermal performance decreases. A test to simulate Long Term Thermal Resistance (LTTR) has been developed to assess this decrease in performance, and data is generally available from the Polyiso and XPS producers. In real-world construction assemblies, the emissions from XPS and Polyiso are slow and the thermal performance change over time for the new gasses is still being studied. If changing R-values are a design concern, EPS emits no gasses and has a proven stable R-value.
VAPOR PERMEANCE
VAPOR PERMEANCE Depending on the application, water vapor permeance may or may not be a design concern. As today s building envelopes become tighter, design professionals are increasingly challenged on how and where to include vapor barriers within the wall or floor assemblies. The primary concern is inclusion of a vapor barrier where it is NOT desired, thus potentially trapping moisture within the assembly, promoting rot and mold growth. Here are some factors to consider when selecting a type of rigid insulation for an assembly:
VAPOR PERMEANCE A vapor barrier is generally defined as having a vapor permeance of less than 1.0 perm Thicker products are generally more vapor retardant than thinner products At 2 thick, EPS-A and EPS-C have a permeance of over 1.5 perm, and are thus not a vapor barriers XPS is typically listed as vapor permeance of less than 1.1 perm at 1 thick, which means that it is a vapor barrier at thicker dimensions. Lab testing shows this to be true. Polyiso is available with several different facer options. The products with foil facers are generally vapor impermeable and the products with coated glass or organic facers are semi permeable.
VAPOR PERMEANCE Vapor barriers are generally NOT recommended on the exterior of wall assemblies in the Midwester or Northerner climate zones 5 through 8 Insulation products that are vapor barriers can be a worse case combination, trapping moisture at the surface of the sheets but allowing moisture vapor to intrude at the edges. If a vapor barrier is desired, use a continuous film rolled product at the desired surface of the assembly vs relying on the insulation Generally, neither EPS-A nor EPS-C are factors in vapor transmission and they allow the designer to strategically place the correct continuous vapor barrier in the assembly without interference from the insulation.
MOISTURE ABSORPTION
MOISTURE ABSORPTION XPS has historically been most specified for below grade application as a result of the testing per ASTM C272. In this test, rigid insulation is immersed in water for 24 hours then tested for water absorption 20 ASTM C272 moisture absorption 15 10 5 0 XPS EPS-C EPS-A
MOISTURE ABSORPTION In a real world scenario, where the foam is continually immersed (XPS, EPS-A and EPS-C), many studies have shown that any of these would become water logged If the insulation system is immersed in water, intrusion at the seams & penetrations create thermal bridging in effect, the insulation value is negated When EPS-A with 1.5% water content from 24 hour immersion was evaluated for R-value, the resulting decrease was only 7% from the stated performance Similar immersed EPS-A samples return to 0% water content via simple diffusion if allowed to dry another 24 hours following immersion
MOISTURE ABSORPTION In real world applications (buried against foundation walls, buried under roads, as part of insulated concrete forming systems) EPS-A and EPS-C products have been excavated after decades of use and found to have no significant reduction in physical or thermal performance When tested, in the lab, in vapor-drive conditions (high humidity and cold surface cycling separated by foam sample), EPS-A and EPS-C showed no loss of physical or thermal performance after 28 days (ASTM C1512). In this test, the sample is frozen repeatedly after water vapor drive and condensation, to test the theory that rigid insulation would break apart in such a scenario from expanding water / ice. EPS-A and EPS-C passed with no physical degradation, as well as samples of XPS In general, XPS, EPS-A and EPS-C are most popular for below grade use. Polyiso can be used below grade but its compressive resistance can be affect by moisture absorption. REGARDLESS OF INSULATION, PROPER DRAINAGE IS CRUCIAL FOR ASSURING LONG TERM PERFORMANCE.
RIGID INSULATION AND TERMITES In California and most of the southern US, the building codes have deemed these very heavy termite infestation areas and do not allow the use of rigid foam insulation below or within 6 of the grade, UNLESS the foam is protected from termite attack by a proven preservative. Another third of the US is considered heavy termite infestation, where the codes don t require protection of the foam from termites, but may be desired by the designer. ICC-ES has created a stringent 3 year field test program and lab study in order to approve termiticide protected products. EPS-A has surpassed these tests against the most prevalent termites for 5 years.
RIGID INSULATION AND TERMITES
RIGID INSULATION AND TERMITES LAB TESTING ¼ X1 X1 SAMPLES FROM SEPARATE LAB JARS WITH 400 TERMITES EACH AFTER 4 WEEKS EXPOSURE XPS AND WOOD CONTROL EPS-C AND WOOD CONTROL EPS-A WITH PREVENTOL 35
RIGID INSULATION AND TERMITES While EPS-A, treated with Preventol, achieved a very high rating against the more aggressive Formosan termite in lab studies, and field studies on wood were favorable, the field studies on EPS-A needed for ICC-ES approval were not conducted. Formosans are generally not a concern in the continental US but are in Hawaii. Where Formosans are a concern, EPS-A is not approved for use below grade. In summary, certain areas of the US do not allow XPS OR EPS-C below grade due to termite concerns. EPS-A was developed to offer a long term solution to code restricted areas and other areas where the designer might have termite concerns.
Learning objective 4: at the end of this program, participants will understand facts regarding sustainability of the various types of rigid insulation.
SUSTAINABILITY MATERIALS & RESOURCES (MR CREDIT ) MR CREDIT 2.1 & 2.2 CONSTRUCTION: DIVERT 50% OR 75% FROM DISPOSAL (2 POINTS POSSIBLE) MR CREDIT 3.1 & 3.2 MATERIALS REUSE: 5% OR 10% (2 POINTS POSSIBLE) MR CREDIT 4.1 & 4.2 RECYCLED CONTENT: 10% OR 20% (2 POINTS POSSIBLE) MR CREDIT 5.1 & 5.2 REGIONAL MATERIALS (2 POINTS POSSIBLE 1 POINT FOR 10% & 2 POINTS FOR 20%) 38
SUSTAINABILITY SUST AIN ABL E SIT ES (SS CREDITS ) SS CREDIT 7.2 HEAT ISLAND REDUCTION: ROOF (1 POINT POSSIBLE) ENERGY & ATMOS PHERE (EA CREDITS ) EA CREDIT 1 OPTIMIZE ENERGY EFFICIENCY PERFORMANCE (10 POINTS POSSIBLE) 39
SUSTAINABILITY CLIMATE CHANGE AND RIGID INSULATION
WHERE CAN YOU RECYCLE? ANY OF THESE FACILITIES AND MORE VISIT WWW.EPSINDUSTRY.ORGFOR MORE INFO 41
REVIEW 1. Components in a well designed below-grade water management system include: Drainage material, drain tile, rigid insulation for protection and energy efficiency, damp-proofing or water proofing membrane and filter fabric. 2. Benefits of a well designed below grade water management system: Reduced energy consumption, better indoor air quality, moderate interior temperatures, reduced mold and moisture issue, increase building durability, and reduce greenhouse gas emissions. 3. The unique attibutes of the various types of rigid insulation: R-value polyiso R-6, XPS R-5, EPS-A R-4.2, EPS-C, R-3.5. Due to release of trapped gasses XPS and polyiso will eventually be the same as EPS-A. Compressive strength polyiso is available up to 25 psi, xps is available up to 100 psi, EPS-A is available up to 60 psi and EPS-C is available up to 10 psi.
REVIEW CONTINUED Vapor permeance polyiso s vapor permeance depends on its facer material, some are permeable, some are not, XPS that is thicker than 1 is a vapor barrier. EPS-A and EPS-C are vapor permeable. Moisture absorption in a 24 hour test, xps performs the best. EPS, XPS, and polyiso will become saturated in poorly drained assemblies long term. EPS and XPS both perform well long term if the assembly is drained. Termite protection this is code required in the south and southwest. Only EPS-A offers and integrated termiticide. 4. Sustainability all four types of rigid insulation can help with LEED credits. All four types can also be recycled. EPS-A and EPS-C are most easily recycled since each molding facility is capable. The blowing agent in XPS is considered to have an extremely high global warming potential. Polyiso s blowing agent could also have high global warming potential. EPS contains only air.
ANY QUESTIONS? THANK YOU FOR YOUR TIME AND ATTENTION 2010 Atlas Roofing Corporation. Atlas EPS is a division of Atlas Roofing. ThermalStar is a registered trademark and X-Grade is a trademark of Atlas Roofing Corporation.