This document discusses vapor barriers and provides recommendations for building enclosures based on climate. It defines key terms like vapor retarder and proposes a classification system. The main points are:
1) Vapor barriers are intended to retard vapor migration while air barriers retard air movement. Confusion exists between the two.
2) Incorrect use of vapor barriers can prevent assemblies from drying out, leading to moisture problems.
3) Recommendations for building enclosures are provided for different climates and construction types to encourage drying and avoid trapping moisture.
4) Key principles include avoiding double vapor barriers, interior vapor barriers in conditioned spaces, and vapor-impermeable finishes that can trap moisture.
This document discusses strategies for controlling rain penetration in building enclosures. There are three main strategies: storage walls which absorb rainwater, perfect barrier walls which prevent all water penetration, and drained walls which allow some rain penetration but include drainage features. Drained walls are now the preferred approach, using cladding to screen rain and an air gap behind to drain water out. Proper design of overhangs, flashing, weep holes and ventilation are also discussed to effectively manage moisture and allow drying. The three key aspects for rain control are deflection of rain, drainage/storage/exclusion, and allowing for drying.
The document summarizes the traditional and modern methods for finishing basements. Traditionally, basements were finished with wood framing, fiberglass insulation, and plastic vapor barriers. However, this approach can trap moisture and lead to mold and rot issues. Modern methods use prefabricated wall panels like SMARTWALL that are designed based on building science principles to manage moisture. SMARTWALL uses semi-permeable vapor barriers, encapsulated framing to prevent thermal bridging, moisture-resistant drywall, and graphite-infused insulation to create a safe, dry, and energy efficient finished basement.
Hidden water leaks are a major issue that cause significant damage and health problems. Standard gypsum wallboard is ineffective in wet areas. There are moisture-resistant products that can help prevent issues from water leaks. While more expensive initially, they will save money long-term by reducing damage, health problems, and repairs. Implementing these products for new construction and renovations requires updating design standards and training architects and managers, but no additional resources.
Intertek BECx & Building Enclosure Design - 2016.05.19 CSI RichmondKeith P. Nelson
This presentation will provide a primer on the practice of Building Enclosure Commissioning (BECx) and its benefits with real world case studies and then dive further into the various approaches as defined by industry standards and code.
2016.05.19 CSI Richmond - Intertek BECx and Building Enclosure Design2Keith P. Nelson
The document provides information about a continuing education course on Building Enclosure Commissioning (BECx). It begins with identifying the course provider, credit information, copyright details, and learning objectives. The majority of the document then focuses on defining key aspects of the building enclosure, including its various components and control layers. It also discusses the BECx process, including its benefits and the typical phases involved - pre-design, design, construction, and operations & maintenance. Overall, the document serves to provide an introduction and overview of BECx for building professionals.
A new method is proposed that can be implemented in case of mine fire. One of the most fatal accidents in Mining is outbreak of mine fire, this method helps to isolate the area under fire and simultaneously tries to diminish the fire to prevent coal loss.
This document discusses strategies for controlling rain penetration in building enclosures. There are three main strategies: storage walls which absorb rainwater, perfect barrier walls which prevent all water penetration, and drained walls which allow some rain penetration but include drainage features. Drained walls are now the preferred approach, using cladding to screen rain and an air gap behind to drain water out. Proper design of overhangs, flashing, weep holes and ventilation are also discussed to effectively manage moisture and allow drying. The three key aspects for rain control are deflection of rain, drainage/storage/exclusion, and allowing for drying.
The document summarizes the traditional and modern methods for finishing basements. Traditionally, basements were finished with wood framing, fiberglass insulation, and plastic vapor barriers. However, this approach can trap moisture and lead to mold and rot issues. Modern methods use prefabricated wall panels like SMARTWALL that are designed based on building science principles to manage moisture. SMARTWALL uses semi-permeable vapor barriers, encapsulated framing to prevent thermal bridging, moisture-resistant drywall, and graphite-infused insulation to create a safe, dry, and energy efficient finished basement.
Hidden water leaks are a major issue that cause significant damage and health problems. Standard gypsum wallboard is ineffective in wet areas. There are moisture-resistant products that can help prevent issues from water leaks. While more expensive initially, they will save money long-term by reducing damage, health problems, and repairs. Implementing these products for new construction and renovations requires updating design standards and training architects and managers, but no additional resources.
Intertek BECx & Building Enclosure Design - 2016.05.19 CSI RichmondKeith P. Nelson
This presentation will provide a primer on the practice of Building Enclosure Commissioning (BECx) and its benefits with real world case studies and then dive further into the various approaches as defined by industry standards and code.
2016.05.19 CSI Richmond - Intertek BECx and Building Enclosure Design2Keith P. Nelson
The document provides information about a continuing education course on Building Enclosure Commissioning (BECx). It begins with identifying the course provider, credit information, copyright details, and learning objectives. The majority of the document then focuses on defining key aspects of the building enclosure, including its various components and control layers. It also discusses the BECx process, including its benefits and the typical phases involved - pre-design, design, construction, and operations & maintenance. Overall, the document serves to provide an introduction and overview of BECx for building professionals.
A new method is proposed that can be implemented in case of mine fire. One of the most fatal accidents in Mining is outbreak of mine fire, this method helps to isolate the area under fire and simultaneously tries to diminish the fire to prevent coal loss.
This document discusses corrosion under insulation (CUI). It occurs when moisture accumulates between insulation and equipment, trapping corrosive components. Factors like moisture, corrosive fluids, and elevated temperatures from insulation can cause corrosion rates of around 4 mm per year in carbon steel. Visual inspection is commonly used to detect CUI but has limitations. Preventing CUI involves stopping water penetration into insulation and using protective barriers to isolate the metal surface from corrosives. Improving insulation system designs and maintaining seals are recommended prevention methods.
This document discusses the benefits of spray foam insulation for reducing energy costs and improving indoor air quality. It states that spray foam insulation provides industry-leading thermal resistance while also improving air quality, reducing drafts, and preventing moisture issues. The document recommends spray foam insulation as the first step to conserve energy and control the internal environment through an efficient building envelope. Spray foam insulation seals the building better than other materials, allowing HVAC systems to be right-sized and saving on equipment and operating costs.
The document discusses duct design and sealing. Some key points:
1) Poorly sealed ductwork is a common problem that wastes energy and can impact comfort and health. Locating ducts inside conditioned spaces eliminates leakage issues.
2) The IECC requires effective sealing materials like mastic and tape to minimize duct leakage. Limiting leakage saves energy and improves indoor air quality.
3) Forced air systems should have balanced airflow between supply and return ducts to prevent pressure imbalances that can increase leakage and backdrafting of combustion appliances. High priority leak areas to seal include disconnected components and connections to the air handler.
Selecting the Correct Underslab MembraneW. R. Meadows
The document discusses underslab vapor retarders and their importance in controlling moisture movement below concrete slabs. It outlines how moisture can enter structures through liquid water, air, and water vapor transmission. Industry standards like ASTM and ACI are referenced which provide classifications for vapor retarders and guidelines on their proper installation. Both arguments for and against the use of cushion courses below vapor retarders are presented.
Recent Planning Experience in Balancing Collection and Building Preservation Needs: Improvements to the Mercer Museum
Presented at 1993 AIC Meeting in Denver
drainage capabilities and heat loss of different inverted roof assembliesAmiran Bokhua
The document summarizes research conducted to evaluate the drainage capabilities and heat loss of different inverted roof assemblies. Tests were performed using a calibrated hot box to simulate winter temperature conditions. Various inverted roof assemblies were tested that included different drainage layer configurations, insulation orientations, and gaps between insulation boards. Test results showed that the majority of rainwater drained at the membrane level regardless of assembly configuration. Introducing gaps between insulation boards increased drainage rates. Assembly configuration was also found to impact the overall effective thermal performance, with increased heat loss observed when the drainage layer was removed and insulation was in direct contact with the roof membrane.
Waterproofing Challenges and Suggested Remedial measures for High Rise Buildi...IJSRD
Leakage can occur in both old and new constructions. Mostly it has been witnessed in old constructions. This indeed is a major problem faced by the buildings. As it is affecting both exterior and interior look of buildings and also causing damage to structural members. It also harms paint of the wall. The problem includes survey of not only leakage, but also dampness and seepage in the residential blocks. This study provide a better and more scientifically based understanding of the role of waterproofing materials to assist the prevention of moisture from penetrating sub-grade walls and slabs. The significance of the research topic is to provide a review of the development of waterproofing materials in implementing waterproofing system in building industry with some case study reference in the current market in India.
The document summarizes an experiment testing different wall cladding systems for water leakage. The author sprayed a brick veneer wall with a hose to test how quickly water would pass through, finding it took under 30 seconds. They then built an eight-sided test structure to evaluate 21 combinations of cladding materials and building papers. By adding a measured amount of water and tracking what comes in and out, they could compare how much water was absorbed by different systems. The experiment found that stucco bonded too tightly to housewrap, destroying the water repellency of the paper and not allowing for drainage. Proper drainage and an air space between cladding and drainage plane are needed for wall systems to manage water effectively.
This document summarizes the properties and benefits of Aerolon, a thermal insulating coating developed by Tnemec that features aerogel as a key ingredient. Aerolon offers superior thermal insulation and protection against corrosion under insulation compared to other coating and insulation options. It has an ultra-low thermal conductivity and high R-value, providing significant energy savings. Aerolon also improves worksite safety by reducing surface temperatures and preventing burns. It can be easily applied to pipes, tanks, and structures in industrial facilities.
Aerogel is a type of solid material that is composed of a gel-like structure, in which the liquid component has been replaced with gas. This results in a material that is extremely lightweight, with a density that can be as low as three times that of air.
Aerogels are often referred to as "frozen smoke" or "solid smoke" due to their translucent, wispy appearance. They were first developed in the 1930s by Samuel Kistler, who used a process called supercritical drying to create the material.
Aerogels are highly insulating, with a thermal conductivity that is much lower than that of traditional insulating materials like fiberglass or foam. They are also highly absorbent, making them useful for applications such as oil spill cleanup or water filtration.
Aerogels can be made from a variety of materials, including silica, carbon, and metal oxides. They are used in a range of industries, including aerospace, energy, and electronics, due to their unique properties and versatility.
whatisaerogelusefor
carbnaerogel
Aerogel properties
Chemical properties of aerogel
aerogel come from natura lmaterials
aerogel change the future
Doped' nanoparticles can absorb more sunlight
Aerogels based on nanoparticles can be used as a photocatalyst, which enables or accelerates chemical reactions (when combined with sunlight) to produce extremely useful products in the modern world, including hydrogen.
NASA aerogel
Aerogel is 1,000 times less dense than glass, another silicon-based solid. This exotic material has many unusual properties, such as uniquely low thermal conductivity, refractive index, and sound speed, in addition to its exceptional ability to capture hypervelocity dust.
Is aerogel used by NASA?
NASA turned to the material to keep rocket fuel at cryogenic temperatures and worked with industry to create the world's first practical, flexible aerogel blankets in the 1990s.
In space, aerogels can be particularly useful for thermal insulation in extreme low-temperature and low pressure environments, such as Mars.
Aerogels: Thinner, Lighter, Stronger,
Picture preparing a bowl full of a sweet, gelatin dessert. The gelatin powder is mixed with hot water, and then the mixture is cooled in a refrigerator until it sets. It is now a gel. If that wiggly gel were placed in an oven and all of the moisture dried out of it, all that would be left would be a pile of powder.
But imagine if the dried gelatin maintained its shape, even after the liquid had been removed. The structure of the gel would remain, but it would be extremely light due to low density. This is precisely how aerogels are made.
Aerogels are among the lightest solid materials known to man. They are created by combining a polymer with a solvent to form a gel, and then removing the liquid from the gel and replacing it with air. Aerogels are extremely porous and very low in density. They are solid to the touch. This translucent material is considered one of the finest insulation materials available. Aerogel
Technical Bulletin 0714 Elastomeric insulation versus polyisocyanurate in low...Dyplast Products
PURPOSE
Several of Dyplast’s prior Technical Bulletins have provided in-depth comparisons of various insulants, including polyisocyanurate (polyiso or PIR), polyurethane (PUR), phenolic, polystyrene (expanded EPS and extruded XPS), cellular glass, and fiberglass - - as well as less-than-comprehensive comparisons with elastomeric and aerogel. Now with somewhat more information becoming available from elastomeric manufacturers and the aggressive marketing from elastomeric suppliers for colder applications it is appropriate to dedicate a Technical Bulletin to elastomeric insulants as compared to polyisocyanurate - - and to a much lesser extent phenolic, and cellular glass.
Technical Bulletin 0714 Elastomeric insulation versus polyisocyanurate in low...Joe Hughes
PURPOSE
Several of Dyplast’s prior Technical Bulletins have provided in-depth comparisons of various insulants, including polyisocyanurate (polyiso or PIR), polyurethane (PUR), phenolic, polystyrene (expanded EPS and extruded XPS), cellular glass, and fiberglass - - as well as less-than-comprehensive comparisons with elastomeric and aerogel. Now with somewhat more information becoming available from elastomeric manufacturers and the aggressive marketing from elastomeric suppliers for colder applications it is appropriate to dedicate a Technical Bulletin to elastomeric insulants as compared to polyisocyanurate - - and to a much lesser extent phenolic, and cellular glass.
This document discusses various methods and materials for waterproofing buildings. It describes common waterproofing materials like polyurethane liquid membranes, cementitious coatings, EPDM rubber, bituminous membranes, PVC, and thermoplastics. It also outlines methods for waterproofing basements, roofs, floors, toilets, and bathrooms. These include interior/exterior drainage systems and vapor barriers. Sheet and liquid-applied membrane waterproofing options are presented along with their advantages.
While work is ongoing to further define the benefits of what has been termed Above-Sheathing Ventilation (ASV), the significance of this information is likely to create a very strong impetus for change in how tile roofs are installed.
Integral damp-proofing involves treating building walls and floors during construction to prevent moisture from passing into interior spaces. There are various methods of damp-proofing including membrane damp-proofing, integral damp-proofing, surface treatment, guniting, and cavity wall construction. Integral damp-proofing works by including waterproofing materials within the concrete itself during construction, giving the concrete a waterproof quality through either hydrophilic or hydrophobic systems. Hydrophilic systems use crystallization technologies while hydrophobic systems use fatty acids to block pores in the concrete.
Over a decade ago, while performing warranty reviews and condition assessments, RDH began to find water-filled blisters under many new cold-applied membranes. In some cases it was so severe that the premature replacement of entire roof assemblies was necessary. This presentation explains the science behind what was going on, and how we were able to develop a fix for future installations.
353 - 356, Badiu 1 RESEARCH REGARDING THE CASUSES OF DEGRADATION OF ROOF SYSTEMSEDUARD C BADIU
The document discusses several factors that can cause degradation of roof systems over time, including extreme temperature fluctuations, wind, rain, snow, hail, traffic on the roof, and installation of equipment. It notes that the type and stability of the roof deck can affect performance, with decks that are too light or flexible contributing to stresses on the roof. Poor ventilation can also lead to issues like mold, rust, sagging decking, and deterioration of roofing materials from excessive heat and moisture buildup. Different types of roofing materials like asphalt shingles and metal roofs each have advantages and disadvantages that can impact their longevity.
Microshield Water Restoration Presentation, John P. Lapotaire, CIEC 7-12-2011John P. Lapotaire, CIEC.
Microshield Environmental Services, John Lapotaire, CIEC, presentation on Restorative Structural Drying.
The presentation helps Insurance Agents and Adjusters understand the process of restorative structural drying, the different categories of water according to the ANSI approved IICRC S-500, as well as the benefits of hiring IICRC trained professionals.
John P. Lapotaire, CIEC
Microshield Environmental Services, LLC
www.Microshield-ES.com
The popularity of LED and other innovative technologies for outdoor luminaires is driven by today’s focus on cost savings, energy savings and environmental sustainability. But if the outdoor luminaire fails prematurely, the costs of repair or replacement quickly offset any savings or other benefits that might have been realised.
Multiple studies have shown that the root cause of premature failure in outdoor luminaires can often be traced to a failure to equalize pressures within the luminaire’s housing.
Susan presented findings from a comparative study of vented and non-vented LED Roadway Streetlight housings. She discussed how luminaire longevity can be affected by the formation of condensation, the diffusion process, and the impact of factors such as temperature. As this study demonstrates, pressure differentials can compromise housing seals and joints, as well as other connection points within the LED lamp itself – which can reduce the longevity of the power-supply drivers and other electronics. Additional data, from a lifetime study of Protective Vents in outdoor enclosures, will further substantiate the benefits of venting enclosures to prevent premature failure of the sensitive electronics within.
Talk by Susan Chambers, W.L. Gore & Associates (UK) Ltd
- Green roofs originated in Germany in the 1960s and 1970s as a way to replace natural spaces lost to rapid urbanization. They provided benefits like stormwater retention and temperature regulation.
- German research in the 1970s and standards established in the 1980s helped establish green roofs as an industry. By the 1990s there were an estimated 160 million square feet of green roofs in Germany, 95% of which were extensive lightweight sedum roofs.
- Proper installation requires following manufacturer specifications and industry standards. Key components include a waterproof membrane, filter fabric, drainage layer, growth medium, and plants. Safety, positive drainage, and compliance with local building codes are also important considerations.
Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
More Related Content
Similar to BSD-106_Understanding Vapor Barriers_2013.pdf
This document discusses corrosion under insulation (CUI). It occurs when moisture accumulates between insulation and equipment, trapping corrosive components. Factors like moisture, corrosive fluids, and elevated temperatures from insulation can cause corrosion rates of around 4 mm per year in carbon steel. Visual inspection is commonly used to detect CUI but has limitations. Preventing CUI involves stopping water penetration into insulation and using protective barriers to isolate the metal surface from corrosives. Improving insulation system designs and maintaining seals are recommended prevention methods.
This document discusses the benefits of spray foam insulation for reducing energy costs and improving indoor air quality. It states that spray foam insulation provides industry-leading thermal resistance while also improving air quality, reducing drafts, and preventing moisture issues. The document recommends spray foam insulation as the first step to conserve energy and control the internal environment through an efficient building envelope. Spray foam insulation seals the building better than other materials, allowing HVAC systems to be right-sized and saving on equipment and operating costs.
The document discusses duct design and sealing. Some key points:
1) Poorly sealed ductwork is a common problem that wastes energy and can impact comfort and health. Locating ducts inside conditioned spaces eliminates leakage issues.
2) The IECC requires effective sealing materials like mastic and tape to minimize duct leakage. Limiting leakage saves energy and improves indoor air quality.
3) Forced air systems should have balanced airflow between supply and return ducts to prevent pressure imbalances that can increase leakage and backdrafting of combustion appliances. High priority leak areas to seal include disconnected components and connections to the air handler.
Selecting the Correct Underslab MembraneW. R. Meadows
The document discusses underslab vapor retarders and their importance in controlling moisture movement below concrete slabs. It outlines how moisture can enter structures through liquid water, air, and water vapor transmission. Industry standards like ASTM and ACI are referenced which provide classifications for vapor retarders and guidelines on their proper installation. Both arguments for and against the use of cushion courses below vapor retarders are presented.
Recent Planning Experience in Balancing Collection and Building Preservation Needs: Improvements to the Mercer Museum
Presented at 1993 AIC Meeting in Denver
drainage capabilities and heat loss of different inverted roof assembliesAmiran Bokhua
The document summarizes research conducted to evaluate the drainage capabilities and heat loss of different inverted roof assemblies. Tests were performed using a calibrated hot box to simulate winter temperature conditions. Various inverted roof assemblies were tested that included different drainage layer configurations, insulation orientations, and gaps between insulation boards. Test results showed that the majority of rainwater drained at the membrane level regardless of assembly configuration. Introducing gaps between insulation boards increased drainage rates. Assembly configuration was also found to impact the overall effective thermal performance, with increased heat loss observed when the drainage layer was removed and insulation was in direct contact with the roof membrane.
Waterproofing Challenges and Suggested Remedial measures for High Rise Buildi...IJSRD
Leakage can occur in both old and new constructions. Mostly it has been witnessed in old constructions. This indeed is a major problem faced by the buildings. As it is affecting both exterior and interior look of buildings and also causing damage to structural members. It also harms paint of the wall. The problem includes survey of not only leakage, but also dampness and seepage in the residential blocks. This study provide a better and more scientifically based understanding of the role of waterproofing materials to assist the prevention of moisture from penetrating sub-grade walls and slabs. The significance of the research topic is to provide a review of the development of waterproofing materials in implementing waterproofing system in building industry with some case study reference in the current market in India.
The document summarizes an experiment testing different wall cladding systems for water leakage. The author sprayed a brick veneer wall with a hose to test how quickly water would pass through, finding it took under 30 seconds. They then built an eight-sided test structure to evaluate 21 combinations of cladding materials and building papers. By adding a measured amount of water and tracking what comes in and out, they could compare how much water was absorbed by different systems. The experiment found that stucco bonded too tightly to housewrap, destroying the water repellency of the paper and not allowing for drainage. Proper drainage and an air space between cladding and drainage plane are needed for wall systems to manage water effectively.
This document summarizes the properties and benefits of Aerolon, a thermal insulating coating developed by Tnemec that features aerogel as a key ingredient. Aerolon offers superior thermal insulation and protection against corrosion under insulation compared to other coating and insulation options. It has an ultra-low thermal conductivity and high R-value, providing significant energy savings. Aerolon also improves worksite safety by reducing surface temperatures and preventing burns. It can be easily applied to pipes, tanks, and structures in industrial facilities.
Aerogel is a type of solid material that is composed of a gel-like structure, in which the liquid component has been replaced with gas. This results in a material that is extremely lightweight, with a density that can be as low as three times that of air.
Aerogels are often referred to as "frozen smoke" or "solid smoke" due to their translucent, wispy appearance. They were first developed in the 1930s by Samuel Kistler, who used a process called supercritical drying to create the material.
Aerogels are highly insulating, with a thermal conductivity that is much lower than that of traditional insulating materials like fiberglass or foam. They are also highly absorbent, making them useful for applications such as oil spill cleanup or water filtration.
Aerogels can be made from a variety of materials, including silica, carbon, and metal oxides. They are used in a range of industries, including aerospace, energy, and electronics, due to their unique properties and versatility.
whatisaerogelusefor
carbnaerogel
Aerogel properties
Chemical properties of aerogel
aerogel come from natura lmaterials
aerogel change the future
Doped' nanoparticles can absorb more sunlight
Aerogels based on nanoparticles can be used as a photocatalyst, which enables or accelerates chemical reactions (when combined with sunlight) to produce extremely useful products in the modern world, including hydrogen.
NASA aerogel
Aerogel is 1,000 times less dense than glass, another silicon-based solid. This exotic material has many unusual properties, such as uniquely low thermal conductivity, refractive index, and sound speed, in addition to its exceptional ability to capture hypervelocity dust.
Is aerogel used by NASA?
NASA turned to the material to keep rocket fuel at cryogenic temperatures and worked with industry to create the world's first practical, flexible aerogel blankets in the 1990s.
In space, aerogels can be particularly useful for thermal insulation in extreme low-temperature and low pressure environments, such as Mars.
Aerogels: Thinner, Lighter, Stronger,
Picture preparing a bowl full of a sweet, gelatin dessert. The gelatin powder is mixed with hot water, and then the mixture is cooled in a refrigerator until it sets. It is now a gel. If that wiggly gel were placed in an oven and all of the moisture dried out of it, all that would be left would be a pile of powder.
But imagine if the dried gelatin maintained its shape, even after the liquid had been removed. The structure of the gel would remain, but it would be extremely light due to low density. This is precisely how aerogels are made.
Aerogels are among the lightest solid materials known to man. They are created by combining a polymer with a solvent to form a gel, and then removing the liquid from the gel and replacing it with air. Aerogels are extremely porous and very low in density. They are solid to the touch. This translucent material is considered one of the finest insulation materials available. Aerogel
Technical Bulletin 0714 Elastomeric insulation versus polyisocyanurate in low...Dyplast Products
PURPOSE
Several of Dyplast’s prior Technical Bulletins have provided in-depth comparisons of various insulants, including polyisocyanurate (polyiso or PIR), polyurethane (PUR), phenolic, polystyrene (expanded EPS and extruded XPS), cellular glass, and fiberglass - - as well as less-than-comprehensive comparisons with elastomeric and aerogel. Now with somewhat more information becoming available from elastomeric manufacturers and the aggressive marketing from elastomeric suppliers for colder applications it is appropriate to dedicate a Technical Bulletin to elastomeric insulants as compared to polyisocyanurate - - and to a much lesser extent phenolic, and cellular glass.
Technical Bulletin 0714 Elastomeric insulation versus polyisocyanurate in low...Joe Hughes
PURPOSE
Several of Dyplast’s prior Technical Bulletins have provided in-depth comparisons of various insulants, including polyisocyanurate (polyiso or PIR), polyurethane (PUR), phenolic, polystyrene (expanded EPS and extruded XPS), cellular glass, and fiberglass - - as well as less-than-comprehensive comparisons with elastomeric and aerogel. Now with somewhat more information becoming available from elastomeric manufacturers and the aggressive marketing from elastomeric suppliers for colder applications it is appropriate to dedicate a Technical Bulletin to elastomeric insulants as compared to polyisocyanurate - - and to a much lesser extent phenolic, and cellular glass.
This document discusses various methods and materials for waterproofing buildings. It describes common waterproofing materials like polyurethane liquid membranes, cementitious coatings, EPDM rubber, bituminous membranes, PVC, and thermoplastics. It also outlines methods for waterproofing basements, roofs, floors, toilets, and bathrooms. These include interior/exterior drainage systems and vapor barriers. Sheet and liquid-applied membrane waterproofing options are presented along with their advantages.
While work is ongoing to further define the benefits of what has been termed Above-Sheathing Ventilation (ASV), the significance of this information is likely to create a very strong impetus for change in how tile roofs are installed.
Integral damp-proofing involves treating building walls and floors during construction to prevent moisture from passing into interior spaces. There are various methods of damp-proofing including membrane damp-proofing, integral damp-proofing, surface treatment, guniting, and cavity wall construction. Integral damp-proofing works by including waterproofing materials within the concrete itself during construction, giving the concrete a waterproof quality through either hydrophilic or hydrophobic systems. Hydrophilic systems use crystallization technologies while hydrophobic systems use fatty acids to block pores in the concrete.
Over a decade ago, while performing warranty reviews and condition assessments, RDH began to find water-filled blisters under many new cold-applied membranes. In some cases it was so severe that the premature replacement of entire roof assemblies was necessary. This presentation explains the science behind what was going on, and how we were able to develop a fix for future installations.
353 - 356, Badiu 1 RESEARCH REGARDING THE CASUSES OF DEGRADATION OF ROOF SYSTEMSEDUARD C BADIU
The document discusses several factors that can cause degradation of roof systems over time, including extreme temperature fluctuations, wind, rain, snow, hail, traffic on the roof, and installation of equipment. It notes that the type and stability of the roof deck can affect performance, with decks that are too light or flexible contributing to stresses on the roof. Poor ventilation can also lead to issues like mold, rust, sagging decking, and deterioration of roofing materials from excessive heat and moisture buildup. Different types of roofing materials like asphalt shingles and metal roofs each have advantages and disadvantages that can impact their longevity.
Microshield Water Restoration Presentation, John P. Lapotaire, CIEC 7-12-2011John P. Lapotaire, CIEC.
Microshield Environmental Services, John Lapotaire, CIEC, presentation on Restorative Structural Drying.
The presentation helps Insurance Agents and Adjusters understand the process of restorative structural drying, the different categories of water according to the ANSI approved IICRC S-500, as well as the benefits of hiring IICRC trained professionals.
John P. Lapotaire, CIEC
Microshield Environmental Services, LLC
www.Microshield-ES.com
The popularity of LED and other innovative technologies for outdoor luminaires is driven by today’s focus on cost savings, energy savings and environmental sustainability. But if the outdoor luminaire fails prematurely, the costs of repair or replacement quickly offset any savings or other benefits that might have been realised.
Multiple studies have shown that the root cause of premature failure in outdoor luminaires can often be traced to a failure to equalize pressures within the luminaire’s housing.
Susan presented findings from a comparative study of vented and non-vented LED Roadway Streetlight housings. She discussed how luminaire longevity can be affected by the formation of condensation, the diffusion process, and the impact of factors such as temperature. As this study demonstrates, pressure differentials can compromise housing seals and joints, as well as other connection points within the LED lamp itself – which can reduce the longevity of the power-supply drivers and other electronics. Additional data, from a lifetime study of Protective Vents in outdoor enclosures, will further substantiate the benefits of venting enclosures to prevent premature failure of the sensitive electronics within.
Talk by Susan Chambers, W.L. Gore & Associates (UK) Ltd
- Green roofs originated in Germany in the 1960s and 1970s as a way to replace natural spaces lost to rapid urbanization. They provided benefits like stormwater retention and temperature regulation.
- German research in the 1970s and standards established in the 1980s helped establish green roofs as an industry. By the 1990s there were an estimated 160 million square feet of green roofs in Germany, 95% of which were extensive lightweight sedum roofs.
- Proper installation requires following manufacturer specifications and industry standards. Key components include a waterproof membrane, filter fabric, drainage layer, growth medium, and plants. Safety, positive drainage, and compliance with local building codes are also important considerations.
Similar to BSD-106_Understanding Vapor Barriers_2013.pdf (20)
Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
CHINA’S GEO-ECONOMIC OUTREACH IN CENTRAL ASIAN COUNTRIES AND FUTURE PROSPECTjpsjournal1
The rivalry between prominent international actors for dominance over Central Asia's hydrocarbon
reserves and the ancient silk trade route, along with China's diplomatic endeavours in the area, has been
referred to as the "New Great Game." This research centres on the power struggle, considering
geopolitical, geostrategic, and geoeconomic variables. Topics including trade, political hegemony, oil
politics, and conventional and nontraditional security are all explored and explained by the researcher.
Using Mackinder's Heartland, Spykman Rimland, and Hegemonic Stability theories, examines China's role
in Central Asia. This study adheres to the empirical epistemological method and has taken care of
objectivity. This study analyze primary and secondary research documents critically to elaborate role of
china’s geo economic outreach in central Asian countries and its future prospect. China is thriving in trade,
pipeline politics, and winning states, according to this study, thanks to important instruments like the
Shanghai Cooperation Organisation and the Belt and Road Economic Initiative. According to this study,
China is seeing significant success in commerce, pipeline politics, and gaining influence on other
governments. This success may be attributed to the effective utilisation of key tools such as the Shanghai
Cooperation Organisation and the Belt and Road Economic Initiative.
6th International Conference on Machine Learning & Applications (CMLA 2024)ClaraZara1
6th International Conference on Machine Learning & Applications (CMLA 2024) will provide an excellent international forum for sharing knowledge and results in theory, methodology and applications of on Machine Learning & Applications.
We have compiled the most important slides from each speaker's presentation. This year’s compilation, available for free, captures the key insights and contributions shared during the DfMAy 2024 conference.
ACEP Magazine edition 4th launched on 05.06.2024Rahul
This document provides information about the third edition of the magazine "Sthapatya" published by the Association of Civil Engineers (Practicing) Aurangabad. It includes messages from current and past presidents of ACEP, memories and photos from past ACEP events, information on life time achievement awards given by ACEP, and a technical article on concrete maintenance, repairs and strengthening. The document highlights activities of ACEP and provides a technical educational article for members.
Low power architecture of logic gates using adiabatic techniquesnooriasukmaningtyas
The growing significance of portable systems to limit power consumption in ultra-large-scale-integration chips of very high density, has recently led to rapid and inventive progresses in low-power design. The most effective technique is adiabatic logic circuit design in energy-efficient hardware. This paper presents two adiabatic approaches for the design of low power circuits, modified positive feedback adiabatic logic (modified PFAL) and the other is direct current diode based positive feedback adiabatic logic (DC-DB PFAL). Logic gates are the preliminary components in any digital circuit design. By improving the performance of basic gates, one can improvise the whole system performance. In this paper proposed circuit design of the low power architecture of OR/NOR, AND/NAND, and XOR/XNOR gates are presented using the said approaches and their results are analyzed for powerdissipation, delay, power-delay-product and rise time and compared with the other adiabatic techniques along with the conventional complementary metal oxide semiconductor (CMOS) designs reported in the literature. It has been found that the designs with DC-DB PFAL technique outperform with the percentage improvement of 65% for NOR gate and 7% for NAND gate and 34% for XNOR gate over the modified PFAL techniques at 10 MHz respectively.
A SYSTEMATIC RISK ASSESSMENT APPROACH FOR SECURING THE SMART IRRIGATION SYSTEMSIJNSA Journal
The smart irrigation system represents an innovative approach to optimize water usage in agricultural and landscaping practices. The integration of cutting-edge technologies, including sensors, actuators, and data analysis, empowers this system to provide accurate monitoring and control of irrigation processes by leveraging real-time environmental conditions. The main objective of a smart irrigation system is to optimize water efficiency, minimize expenses, and foster the adoption of sustainable water management methods. This paper conducts a systematic risk assessment by exploring the key components/assets and their functionalities in the smart irrigation system. The crucial role of sensors in gathering data on soil moisture, weather patterns, and plant well-being is emphasized in this system. These sensors enable intelligent decision-making in irrigation scheduling and water distribution, leading to enhanced water efficiency and sustainable water management practices. Actuators enable automated control of irrigation devices, ensuring precise and targeted water delivery to plants. Additionally, the paper addresses the potential threat and vulnerabilities associated with smart irrigation systems. It discusses limitations of the system, such as power constraints and computational capabilities, and calculates the potential security risks. The paper suggests possible risk treatment methods for effective secure system operation. In conclusion, the paper emphasizes the significant benefits of implementing smart irrigation systems, including improved water conservation, increased crop yield, and reduced environmental impact. Additionally, based on the security analysis conducted, the paper recommends the implementation of countermeasures and security approaches to address vulnerabilities and ensure the integrity and reliability of the system. By incorporating these measures, smart irrigation technology can revolutionize water management practices in agriculture, promoting sustainability, resource efficiency, and safeguarding against potential security threats.
International Conference on NLP, Artificial Intelligence, Machine Learning an...gerogepatton
International Conference on NLP, Artificial Intelligence, Machine Learning and Applications (NLAIM 2024) offers a premier global platform for exchanging insights and findings in the theory, methodology, and applications of NLP, Artificial Intelligence, Machine Learning, and their applications. The conference seeks substantial contributions across all key domains of NLP, Artificial Intelligence, Machine Learning, and their practical applications, aiming to foster both theoretical advancements and real-world implementations. With a focus on facilitating collaboration between researchers and practitioners from academia and industry, the conference serves as a nexus for sharing the latest developments in the field.
2. 2 Building Science Digest 106
This can be a problem when there is also a vapor barrier on the exterior. This can be a
problem where brick is installed over building paper and vapor permeable sheathing.
What Do We Really Want to Do?
Two seemingly simple requirements for building enclosures bedevil engineers and
architects almost endlessly:
• keep water out
• let water out if it gets in
Water can come in several phases: liquid, solid, vapor and adsorbed. The liquid phase
as rain and ground water has driven everyone crazy for hundreds of years but can be
readily understood - drain everything and remember the humble flashing. The solid
phase also drives everyone crazy when we have to shovel it or melt it, but at least most
professionals understand the related building problems (ice damming, frost heave,
freeze-thaw damage). But the vapor phase is in a class of craziness all by itself. We
will conveniently ignore the adsorbed phase and leave it for someone else to deal with.
Note that adsorbed water is different than absorbed water (see Kumaran, Mitalas &
Bomberg, 1994).
The fundamental principle of control of water in the liquid form is to drain it out if it
gets in – and let us make it perfectly clear – it will get in if you build where it rains or if
you put your building in the ground where there is water in the ground. This is easy to
understand, logical, with a long historical basis.
The fundamental principle of control of water in the solid form is to not let it get solid
and if it does – give it space or if it is solid not let it get liquid and if it does drain it
away before it can get solid again. This is a little more difficult to understand, but
logical and based on solid research. Examples of this principle include the use of air
entrained concrete to control freeze-thaw damage and the use of attic venting to
provide cold roof decks to control ice damming.
The fundamental principle of control of water in the vapor form is to keep it out and
to let it out if it gets in. Simple right? No chance. It gets complicated because
sometimes the best strategies to keep water vapor out also trap water vapor in. This
can be a real problem if the assemblies start out wet because of rain or the use of wet
materials.
It gets even more complicated because of climate. In general water vapor moves from
the warm side of building assemblies to the cold side of building assemblies. This is
simple to understand, except we have trouble deciding what side of a wall is the cold
or warm side. Logically, this means we need different strategies for different climates.
We also have to take into account differences between summer and winter.
Finally, complications arise when materials can store water. This can be both good
and bad. A cladding system such as a brick veneer can act as a reservoir after a
3. Understanding Vapor Barriers 3
rainstorm and significantly complicate wall design. Alternatively, wood framing or
masonry can act as a hygric buffer absorbing water lessening moisture shocks.
What is required is to define vapor control measures on a more regional climatic basis
and to define the vapor control measures more precisely.
Part of the problem is that we struggle with names and terms. We have vapor
retarders, we have vapor barriers, we have vapor permeable we have vapor
impermeable, etc. What do these terms mean? It depends on whom you ask and
whether they are selling something or arguing with a building official. In an attempt to
clear up some of the confusion the following definitions are proposed:
Vapor Retarder*: The element that is designed and installed in an
assembly to retard the movement of water by vapor
diffusion.
* taken somewhat from ASHRAE Fundamentals 2001, Chapter 23.
The unit of measurement typically used in characterizing the water vapor permeance of
materials is the “perm”. It is further proposed here that there should be several classes
of vapor retarders (this is nothing new – it is an extension and modification of the
Canadian General Standards Board approach that specifies Type I and Type II vapor
retarders – the numbers here are a little different however):
Class I Vapor Retarder: 0.1 perm or less
Class II Vapor Retarder: 1.0 perm or less and greater than 0.1 perm
Class III Vapor Retarder: 10 perm or less and greater than 1.0 perm
Test Procedure for vapor retarders: ASTM E-96 Test Method A (the
desiccant method or dry cup
method)
Finally, a vapor barrier is defined as:
Vapor Barrier: A Class I vapor retarder.
The current International Building Code (and its derivative codes) defines a vapor
retarder as 1.0 perm or less (using the same test procedure). In other words the
current code definition of a vapor retarder is equivalent to the definition of a Class II
Vapor Retarder proposed by the author.
Continuing in the spirit of finally defining terms that are tossed around in the
enclosure business. It is also proposed that materials be separated into four general
classes based on their permeance (again nothing new, this is an extension of the
discussion in ASHRAE Journal, February 02 – Moisture Control for Buildings):
4. 4 Building Science Digest 106
Vapor impermeable: 0.1 perm or less
Vapor semi-impermeable: 1.0 perm or less and greater than 0.1 perm
Vapor semi-permeable: 10 perms or less and greater than 1.0 perm
Vapor permeable: greater than 10 perms
Recommendations for Building Enclosures
The following building assembly recommendations are climatically based (see SIDE
BAR 1) and are sensitive to cladding type (brick or stone veneer, stucco) and structure
(concrete block, steel or wood frame, precast concrete).
The recommendations apply to residential, business, assembly, and educational and
mercantile occupancies. The recommendations do not apply to special use enclosures
such as spas, pool buildings, museums, hospitals, data processing centers or other
engineered enclosures such as factory, storage or utility enclosures.
The recommendations are based on the following principles:
• Avoidance of using vapor barriers where vapor retarders will provide
satisfactory performance. Avoidance of using vapor retarders where vapor
permeable materials will provide satisfactory performance. Thereby
encouraging drying mechanisms over wetting prevention mechanisms.
• Avoidance of the installation of vapor barriers on both sides of assemblies –
i.e. “double vapor barriers” in order to facilitate assembly drying in at least one
direction.
• Avoidance of the installation of vapor barriers such as polyethylene vapor
barriers, foil faced batt insulation and reflective radiant barrier foil insulation
on the interior of air-conditioned assemblies – a practice that has been linked
with moldy buildings (Lstiburek, 2002).
• Avoidance of the installation of vinyl wall coverings on the inside of air-
conditioned assemblies – a practice that has been linked with moldy buildings
(Lstiburek, 1993).
• Enclosures are ventilated meeting ASHRAE Standard 62.2 or 62.1.
Each of the recommended building assemblies were evaluated using dynamic
hygrothermal modeling. The moisture content of building materials that comprise the
building assemblies all remained below the equilibrium moisture content of the
materials as specified in ASHRAE 160 P under this evaluation approach. Interior air
conditions and exterior air conditions as specified by ASHRAE 160 P were used.
WUFI was used as the modeling program (Kunzel, 1999).
5. Understanding Vapor Barriers 5
More significantly, each of the recommended building assemblies have been found by
the author to provide satisfactory performance under the limitations noted.
Satisfactory performance is defined as no moisture problems reported or observed
over at least a 10 year period.
Figure 1: Concrete Block With Exterior Insulation and Brick or Stone Veneer
Applicability – all hygro-thermal regions
This is arguably the most durable wall assembly available to architects and engineers. It is
constructed from non-water sensitive materials and due to the block construction has a
large moisture storage (or hygric buffer) capacity. It can be constructed virtually anywhere.
In cold climates condensation is limited on the interior side of the vapor barrier as a result of
installing all of the thermal insulation on the exterior side of the vapor barrier (which is also
the drainage plane and air barrier in this assembly). In hot climates any moisture that
condenses on the exterior side of the vapor barrier will be drained to the exterior since the
vapor barrier is also a drainage plane. This wall assembly will dry from the vapor barrier
inwards and will dry from the vapor barrier outwards.
6. 6 Building Science Digest 106
Figure 2: Concrete Block With Interior Frame Wall Cavity Insulation and Brick or Stone
Veneer
Applicability – Limited to mixed-humid, hot-humid, mixed-dry, hot-dry and marine regions –
should not be used in cold, very cold, and subarctic/arctic regions
This wall assembly has all of the thermal insulation installed to the interior of the vapor
barrier and therefore should not be used in cold regions or colder. It is also a durable
assembly due to the block construction and the associated moisture storage (hygric buffer)
capacity. The wall assembly does contain water sensitive cavity insulation (except where
spray foam is used) and it is important that this assembly can dry inwards – therefore vapor
semi impermeable interior finishes such as vinyl wall coverings should be avoided. In this
wall assembly the vapor barrier is also the drainage plane and air barrier.
7. 7
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Figure 3: Concrete Block With Interior Rigid Insulation and Stucco
Applicability – all hygro-thermal regions*
* In very cold and subarctic/arctic regions vapor impermeable foam sheathings are
recommended
This assembly has all of the thermal insulation installed on the interior of the concrete block
construction but differs from Figure 2 since it does not have a vapor barrier on the exterior.
The assembly also does not have a vapor barrier on the interior of the assembly. It has a
large moisture storage (hygric buffer) capacity due to the block construction. The rigid
insulation installed on the interior should ideally be non-moisture sensitive and allow the wall
to dry inwards – hence the recommended use of vapor semi permeable foam sheathing.
Note that foam sheathing faced with aluminum foil or polypropylene skins would also be
acceptable provided only non-moisture sensitive materials are used at the masonry block to
insulation interface. It is important that this assembly inboard of the foam sheathing can dry
inwards except in very cold and subarctic/arctic regions – therefore vapor semi impermeable
interior finishes such as vinyl wall coverings should be avoided in assemblies – except in
very cold and subarctic/arctic regions. Vapor impermeable foam sheathings should be used
in place of the vapor semi permeable foam sheathings in very cold and subarctic/arctic
regions. The drainage plane in this assembly is the latex painted stucco rendering. A Class
III vapor retarder is located on both the interior and exterior of the assembly (the latex paint
on the stucco and on the interior gypsum board).
8. 6
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Figure 4: Concrete Block With Interior Rigid Insulation/Frame Wall With Cavity Insulation
and Stucco
Applicability – all hygro-thermal regions*
* In very cold and sub arctic/arctic regions vapor impermeable foam sheathings are
recommended – additionally the thickness of the foam sheathing should be determined by
hygro-thermal analysis so that the interior surface of the foam sheathing remains above the
dew point temperature of the interior air (see Side Bar 2)
This assembly is a variation on Figure 3. It also has all of the thermal insulation installed on
the interior of the concrete block construction but differs from Figure 3 due to the addition of
a frame wall to the interior of the rigid insulation. This assembly also does not have a vapor
barrier on the exterior. The assembly also does not have a vapor barrier on the interior of the
assembly. It has a large moisture storage (hygric buffer) capacity due to the block construc-
tion. The rigid insulation installed on the interior should ideally be non-moisture sensitive and
allow the wall to dry inwards — hence the recommended use of vapor semi permeable foam
sheathing. Note that foam sheathing faced with aluminum foil or polypropylene skins would
also be acceptable provided only non-moisture sensitive materials are used at the masonry
block to insulation interface. It is important that this assembly inboard of the rigid insulation
can dry inwards even in very cold and subarctic/arctic regions — therefore vapor semi
impermeable interior finished such as vinyl wall coverings should be avoided in assemblies.
Vapor impermeable foam sheathings should be used in place of the vapor semi permeable
foam sheathings in very cold and subarctic/arctic regions. The drainage plane in this
assembly is the latex painted stucco rendering. A Class III vapor retarder is located on both
the interior and exterior of the assembly (the latex paint on the stucco and on the interior
gypsum board).
9. Understanding Vapor Barriers 9
Figure 5: Frame Wall With Exterior Insulation and Brick or Stone Veneer
Applicability – all hygro-thermal regions
This wall is a variation of Figure 1 – but without the moisture storage (or hygric buffer)
capacity. This wall is also a durable wall assembly. It is constructed from non-water
sensitive materials and has a high drying potential inwards due to the frame wall cavity not
being insulated. It can also be constructed virtually anywhere. In cold climates
condensation is limited on the interior side of the vapor barrier as a result of installing all of
the thermal insulation on the exterior side of the vapor barrier (which is also the drainage
plane and air barrier in this assembly). In hot climates any moisture that condenses on the
exterior side of the vapor barrier will be drained to the exterior since the vapor barrier is also
a drainage plane. This wall assembly will dry from the vapor barrier inwards and will dry
from the vapor barrier outwards.
10. 10 Building Science Digest 106
Figure 6: Frame Wall With Cavity Insulation and Brick or Stone Veneer
Applicability – Limited to mixed-humid, hot-humid, mixed-dry, hot-dry and marine regions –
can be used with hygro-thermal analysis in some areas in cold regions (Zone 5, but not
Zone 6 see Side Bar 2)- should not be used in very cold and subarctic/arctic regions
This wall is a flow through assembly – it can dry to both the exterior and the interior. It has a
Class III vapor retarder on the interior of the assembly (the latex paint on the gypsum
board). It is critical in this wall assembly that the exterior brick veneer (a “reservoir”
cladding) be uncoupled from the wall assembly with a ventilated and drained cavity. The
cavity behind the brick veneer should be at least 2 inches wide (source: Brick Institute of
America) and free from mortar droppings. It must also have air inlets (“weep holes”) at its
base and air outlets (“weep holes”) at its top in order to provide back ventilation of the brick
veneer. The drainage plane in this assembly is the building paper or building wrap. The air
barrier can be any of the following: the interior gypsum board, the exterior gypsum wallboard
or the exterior building wrap.
11. Understanding Vapor Barriers 11
Figure 7: Frame Wall With Cavity Insulation and Brick or Stone Veneer
Applicability – Limited to mixed-humid, hot-humid, mixed-dry, hot-dry and marine regions –
can be used with hygro-thermal analysis in some areas in cold regions (Zone 5, but not
Zone 6 see side bar 3)- should not be used in very cold and subarctic/arctic regions
This wall is a variation of Figure 6. The exterior gypsum sheathing becomes the drainage
plane. As in Figure 6 this wall is a flow through assembly – it can dry to both the exterior
and the interior. It has a Class III vapor retarder on the interior of the assembly (the latex
paint on the gypsum board). It is also critical in this wall assembly that the exterior brick
veneer (a “reservoir” cladding) be uncoupled from the wall assembly with a ventilated and
drained cavity. The cavity behind the brick veneer should be at least 2 inches wide (source:
Brick Institute of America) and free from mortar droppings. It must also have air inlets
(“weep holes”) at its base and air outlets (“weep holes”) at its top in order to provide back
ventilation of the brick veneer. The air barrier in this assembly can be either the interior
gypsum board or the exterior gypsum sheathing.
12. 12 Building Science Digest 106
Figure 8: Frame Wall With Exterior Rigid Insulation With Cavity Insulation and Brick or
Stone Veneer
Applicability – all hygro-thermal regions except subarctic/arctic – in cold and very cold
regions the thickness of the foam sheathing should be determined by hygro-thermal
analysis so that the interior surface of the foam sheathing remains above the dew point
temperature of the interior air (see Side Bar 2)
This wall is a variation of Figure 5. In cold climates condensation is limited on the interior
side of the vapor barrier as a result of installing some of the thermal insulation on the
exterior side of the vapor barrier (which is also the drainage plane and air barrier in this
assembly). In hot climates any moisture that condenses on the exterior side of the vapor
barrier will be drained to the exterior since the vapor barrier is also a drainage plane. This
wall assembly will dry from the vapor barrier inwards and will dry from the vapor barrier
outwards. Since this wall assembly has a vapor barrier that is also a drainage plane it is not
necessary to back vent the brick veneer reservoir cladding as in Figure 6 and Figure 7.
Moisture driven inwards out of the brick veneer will condense on the vapor barrier/drainage
plane and be drained outwards.
13. Understanding Vapor Barriers 13
Figure 9: Frame Wall With Cavity Insulation and Brick or Stone Veneer With Interior Vapor
Retarder
Applicability – Limited to cold and very cold regions
This wall is a variation of Figure 6 except it has a Class II vapor retarder on the interior
limiting its inward drying potential – but not eliminating it. It still considered a flow through
assembly – it can dry to both the exterior and the interior. It is critical in this wall assembly
– as in Figure 6 and Figure 7 - that the exterior brick veneer (a “reservoir” cladding) be
uncoupled from the wall assembly with a ventilated and drained cavity. The cavity behind
the brick veneer should be at least 2 inches wide (source: Brick Institute of America) and
free from mortar droppings. It must also have air inlets (“weep holes”) at its base and air
outlets (“weep holes”) at its top in order to provide back ventilation of the brick veneer. The
drainage plane in this assembly is the building paper or building wrap. The air barrier can
be any of the following: the interior gypsum board, the exterior gypsum board or the exterior
building wrap.
14. 14 Building Science Digest 106
Figure 10: Frame Wall With Cavity Insulation and Brick or Stone Veneer With Interior Vapor
Barrier
Applicability – Limited to very cold, subarctic and arctic regions
This wall is a further variation of Figure 6 but now it has a Class I vapor retarder on the
interior (a “vapor barrier”) completely eliminating any inward drying potential. It is
considered the “classic” cold climate wall assembly. It is critical in this wall assembly – as
in Figure 6, Figure 7 and Figure 9 - that the exterior brick veneer (a “reservoir” cladding) be
uncoupled from the wall assembly with a ventilated and drained cavity. The cavity behind
the brick veneer should be at least 2 inches wide (source: Brick Institute of America) and
free from mortar droppings. It must also have air inlets at its base and air outlets at its top in
order to provide back ventilation of the brick veneer. The drainage plane in this assembly is
the building paper or building wrap. The air barrier can be any of the following: the interior
polyethylene vapor barrier, the interior gypsum board, the exterior gypsum board or the
exterior building wrap.
15. Understanding Vapor Barriers 15
Figure 11: Frame Wall With Cavity Insulation and Stucco
Applicability – Limited to mixed-humid, hot-humid, mixed-dry, and hot-dry regions should not
be used in marine, cold, very cold, and subarctic/arctic regions
This wall is also a flow through assembly similar to Figure 6 – but without the brick veneer –
it has a stucco cladding. It can dry to both the exterior and the interior. It has a Class III
vapor retarder on the interior of the assembly (the latex paint on the gypsum board). It is
critical in this wall assembly that a drainage space be provided between the stucco
rendering and the drainage plane. This can be accomplished by installing a bond break (a
layer of tar paper) between the drainage plane and the stucco. A spacer mat can also be
used to increase drainability. Alternatively, a textured or profiled drainage plane (building
wrap) can be used. The drainage plane in this assembly is the building paper or building
wrap. The air barrier can be any of the following: the interior gypsum board, the exterior
stucco rendering, the exterior sheathing or the exterior building wrap.
16. 16 Building Science Digest 106
Figure 12: Frame Wall With Cavity Insulation and Stucco With Interior Vapor Retarder
Applicability – Limited to marine, cold and very cold regions
This wall is a variation of Figure 6 and Figure 11 except it has a Class II vapor retarder on
the interior limiting its inward drying potential – but not eliminating it. It still considered a
flow through assembly – it can dry to both the exterior and the interior. It is critical in this
wall assembly – as in Figure 11 – that a drainage space be provided between the stucco
rendering and the drainage plane. This can be accomplished by installing a bond break (a
layer of tar paper) between the drainage plane and the stucco. A spacer mat can also be
used to increase drainability. Alternatively, a textured or profiled drainage plane (building
wrap) can be used. The drainage plane in this assembly is the building paper or building
wrap. The air barrier can be any of the following: the interior gypsum board, the exterior
stucco rendering, the exterior sheathing or the exterior building wrap.
17. Understanding Vapor Barriers 17
Figure 13: Frame Wall With Exterior Rigid Insulation With Cavity Insulation and Stucco
Applicability – all hygro-thermal regions except subarctic/arctic – in cold and very cold
regions the thickness of the foam sheathing should be determined by hygro-thermal
analysis so that the interior surface of the foam sheathing remains above the dew point
temperature of the interior air (see Side Bar 2)
This is a water managed exterior insulation finish system (EIFS). Unlike “face-sealed” EIFS
this wall has a drainage plane inboard of the exterior stucco skin that is drained to the
exterior. It is also a flow through assembly similar to Figure 6. It can dry to both the exterior
and the interior. It has a Class III vapor retarder on the interior of the assembly (the latex
paint on the gypsum board). It is critical in this wall assembly that a drainage space be
provided between the exterior rigid insulation and the drainage plane. This can be
accomplished by installing a spacer mat or by providing drainage channels in the back of
the rigid insulation. Alternatively, a textured or profiled drainage plane (building wrap) can
be used. The drainage plane in this assembly is the building paper or building wrap. The
air barrier can be any of the following: the interior gypsum board, the exterior stucco
rendering, the exterior sheathing or the exterior building wrap.
18. 18 Building Science Digest 106
Figure 14: Precast Concrete With Interior Frame Wall Cavity Insulation
Applicability – Limited to mixed-humid, hot-humid, mixed-dry, hot-dry and marine regions –
should not be used in cold, very cold, and subarctic/arctic regions
The vapor barrier in this assembly is the precast concrete itself. Therefore this wall
assembly has all of the thermal insulation installed to the interior of the vapor barrier. Of
particular concern is the fact that the thermal insulation is air permeable (except where
spray foam is used). Therefore this wall assembly should not be used in cold regions or
colder. It has a small moisture storage (hygric buffer) capacity due to the precast concrete
construction. The wall assembly does contain water sensitive cavity insulation (except
where spray foam is used) and it is important that this assembly can dry inwards – therefore
vapor semi impermeable interior finishes such as vinyl wall coverings should be avoided. In
this wall assembly the precast concrete is also the drainage plane and air barrier.
19. 9
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Figure 15: Precast Concrete With Interior Rigid Insulation
Applicability – all hygro-thermal regions*
* In very cold and subarctic/arctic regions vapor impermeable foam sheathings are
recommended
This assembly has all of the thermal insulation installed on the interior of the precast
concrete. The assembly also does not have a vapor barrier on the interior of the assembly. It
has a small moistuure storage (hygric buffer) capacity due to the precast concrete construc-
tion. The rigid insulation installed on the interior should ideally be non-moisture sensitive and
allow the wall to dry inwards — hence the recommended use of vapor semi permeable foam
sheathing. Note that foam sheathing faced with aluminum foil or polypropylene skins would
also be acceptable provided only non-moisture sensitive materials are used at the concrete
to insulation interface. It is important that this assembly inboard of the foam sheathing can
dry inwards except in very cold subarctic/arctic regions — therefore vapor semi impermeable
interior finishes such as vinyl wall coverings should be avoided in assemblies — except in
very cold and subarctic/arctic regions. Vapor impermeable foam sheathings should be used
in place of the vapor semi permeable foam sheathings in very cold and subarctic/arctic
regions. The drainage plane in this assembly is the latex painted precast concrete. A Class
III vapor retarder is located on both the interior and exterior of the assembly (the latex paint
on the stucco and on the interior gypsum board).
20. 20 Building Science Digest 106
Figure 16: Precast Concrete With Interior Spray Applied Foam Insulation
Applicability – all hygro-thermal regions*
This assembly has all of the thermal insulation installed on the interior of the precast
concrete. The assembly also does not have a vapor barrier on the interior of the assembly.
It has a small moisture storage (hygric buffer) capacity due to the precast concrete
construction. The spray foam insulation installed on the interior of the precast concrete is
non-moisture sensitive and allows the wall to dry inwards. It is important that this assembly
can dry inwards except in very cold and subarctic/arctic regions – therefore vapor semi
impermeable interior finishes such as vinyl wall coverings should be avoided in assemblies
– except in very cold and subarctic/arctic regions. High-density spray foam, due to its vapor
semi impermeable characteristics should be used in place of low-density foam in very cold
and subarctic/arctic regions. The drainage plane in this assembly is the latex painted
precast concrete. A Class III vapor retarder is located on both the interior and exterior of the
assembly (the latex paint on the stucco and on the interior gypsum board.
* In very cold and subarctic/arctic regions high-density spray foam (vapor semi
impermeable) is recommended
21. Understanding Vapor Barriers 21
References
Kumaran, M.K., Mitalas, G.P., and Bomberg, M.T.; Fundamentals of Transport and Storage
of Moisture in Building Materials and Components; Moisture Control in Buildings, ASTM
Manual Series: MNL 18, ASTM Publication Code (PCN) 28-018094-10, Philadelphia,
PA, 1994.
Kunzel, H.M.; WUFI: PC Program for Calculating the Coupled Heat and Moisture Transfer in
Building Components; Fraunhofer Institute for Building Physics, Holzkirchen, Germany,
1999.
Lstiburek, J.W.; Humidity Control in the Humid South, Workshop Proceedings – Bugs,
Mold & Rot II, BETEC, Washington, November 1993.
Lstiburek, J.W.; “Moisture Control For Buildings;” ASHRAE Journal, February 2002.
Lstiburek, J.W.; “Investigating Diagnosing Moisture Problems,” ASHRAE Journal,
December 2002.
Quirouette, R.L.; The Difference Between a Vapor Barrier and an Air Barrier; Building
Practice Note 54, Division of Building Research, National Research Council of
Canada, ISSN 0701-5216, Ottawa, Ontario, Canada, July 1985.
Rose, W.; Moisture Control in the Modern Building Envelope: The History of the Vapor Barrier
in the US – 1923 to 1952, APT, Volume XXVIII, Number 4, 1997.
Limits of Liability and Disclaimer of Warranty:
Building Science Digests are information articles intended for professionals. The author and the publisher of this article have used their
best efforts to provide accurate and authoritative information in regard to the subject matter covered. The author and publisher make
no warranty of any kind, expressed or implied, with regard to the information contained in this article.
The information presented in this article must be used with care by professionals who understand the implications of what they are
doing. If professional advice or other expert assistance is required, the services of a competent professional shall be sought. The author
and publisher shall not be liable in the event of incidental or consequential damages in connection with, or arising from, the use of the
information contained within this Building Science Digest.
Joseph Lstiburek, Ph.D., P.Eng., is a principal of Building Science Corporation in
Somerville, Massachusetts. He has twenty-five years of experience in design,
construction, investigation, and building science research. Joe is an ASHRAE
Fellow and an internationally recognized authority on indoor air quality, moisture,
and condensation in buildings. More information about Joseph Lstiburek can be
found at www.buildingsciencecorp.com
22. 22 Building Science Digest 106
Hygro-Thermal Regions
Subarctic and Arctic
A subarctic and arctic climate is defined as a region with approximately 12,600 heating
degree days (65 degrees F basis) [7,000 heating degree days (18 degrees C basis)] or greater.
Side Bar 1
23. Understanding Vapor Barriers 23
Very Cold
A very cold climate is defined as a region with approximately 9,000 heating degree days
or greater (65 degrees F basis) [5,000 heating degree days (18 degrees C basis)] or
greater and less than 12,600 heating degree days (65 degrees F basis) [7,000 heating
degree days (18 degrees C basis)].
Cold
A cold climate is defined as a region with approximately 5,400 heating degree days (65
degrees F basis) [3,000 heating degree days (18 degrees C basis)] or greater and less than
approximately 9,000 heating degree days (65 degrees F basis) [5,000 heating degree days
(18 degrees C basis)]
Mixed-Humid
A mixed-humid and warm-humid climate is defined as a region that receives more than
20 inches (50 cm) of annual precipitation with approximately 4,500 cooling degree days
(50 degrees F basis) [2,500 cooling degree days (10 degrees C basis)] or greater and less than
approximately 6,300 cooling degree days (50 degrees F basis) [3,500 cooling degree days
(10 degrees C basis)] and less than approximately 5,400 heating degree days (65 degrees F
basis) [3,000 heating degree days (18 degrees C basis)] and where the average monthly
outdoor temperature drops below 45 degrees F (7 degrees C) during the winter
months.
Marine
A marine climate meets is defined as a region where all of the following occur:
• a mean temperature of the coldest month between 27 degrees F (-3 degrees C)
and 65 degrees F (18 degrees C);
• a mean temperature of the warmest month below 72 degrees F (18 degrees C);
• at least four months with mean temperatures over 50 degrees F (10 degrees C);
and
• a dry season in the summer, the month with the heaviest precipitation in the
cold season has at least three times as much precipitation as the month with
the least precipitation
Hot-Humid
A hot-humid climate is defined as a region that receives more than 20 inches (50 cm) of
annual precipitation with approximately 6,300 cooling degree days (50 degrees F basis)
[3,500 cooling degree days (10 degrees C basis)] or greater and where the monthly average
outdoor temperature remains above 45 degrees F (7 degrees C) throughout the year.
This definition characterizes a region that is similar to the ASHRAE definition of hot-
humid climates where one or both of the following occur:
24. 24 Building Science Digest 106
• a 67 degree F (19.5 degrees C) or higher wet bulb temperature for 3,000 or more
hours during the warmest six consecutive months of the year; or
• a 73 degree F (23 degrees C) or higher wet bulb temperature for 1,500 or more
hours during the warmest six consecutive months of the year.
Hot-Dry, Warm-Dry and Mixed-Dry
A hot-dry climate is defined as region that receives less than 20 inches (50 cm) of
annual precipitation with approximately 6,300 cooling degree days (50 degrees F basis)
[3,500 cooling degree days (10 degrees C basis)] or greater and where the monthly average
outdoor temperature remains above 45 degrees F (7 degrees C) throughout the year.
A warm-dry and mixed-dry climate is defined as a region that receives less than 20
inches (50 cm) of annual precipitation with approximately 4,500 cooling degree days (50
degrees F basis) [2,500 cooling degree day (10 degrees C basis)] or greater and less than
approximately 6,300 cooling degree days (50 degrees F basis) [3,500 cooling degree days
(10 degrees C basis)] and less than approximately 5,400 heating degree days (65 degrees F
basis) [3,000 heating degree days (18 degrees C basis)] and where the average monthly
outdoor temperature drops below 45 degrees F (7 degrees C) during the winter months.
25. Understanding Vapor Barriers 25
Recommendations for Vapor Retarders
The recommendations are based on a combination of field experience and laboratory
testing. The requirements were also evaluated using dynamic hygrothermal modeling.
The modeling program used was WUFI (Kunzel, 1999). Under the modeling
evaluation, the moisture content of building materials that comprise the building
assemblies evaluated all remained below the equilibrium moisture content of the
materials as specified in ASHRAE 160 P. Interior air conditions and exterior air
conditions as specified by ASHRAE 160 P were used. Enclosures are ventilated
meeting ASHRAE Standard 62.1 or 62.2.
The climate zones referenced are the U.S. Department of Energy climate zones as
proposed for adoption in the 2006 International Residential Code (IRC) and
International Energy Conservation Code (IECC). Their development is the subject of
two ASHRAE papers (Briggs, Lucas & Taylor, 2003). An accompanying map defines
the climate zones.
Note that vapor retarders are defined and classed using ASTM E-96 Test Method A
(the desiccant method or dry cup method) or Test Method B (the wet cup method).
1. Zone 1, Zone 2, Zone 3 and Zone 4 (except Zone 4 Marine) do not require
any class of vapor retarder on the interior surface of insulation in insulated
wall and floor assemblies.
2. Zone 4 (marine) requires a Class II (or lower) vapor retarder on the interior
surface of insulation in insulated wall and floor assemblies where the
permeance of the exterior sheathing/cladding assembly is less than or equal to
Side Bar 2
26. 26 Building Science Digest 106
1.0 perm and greater than 0.1 perm as tested by Test Method B (the “wet cup”
method) of ASTM E-96).
3. Zone 4 (marine) requires a Class III (or lower) vapor retarder on the interior
surface of insulation in insulated wall and floor assemblies where the
permeance of the exterior sheathing is 0.1 perm or less as tested by Test
Method B (the “wet cup” method) of ASTM E-96) and the interior surface of
the exterior sheathing shall be maintained above the dew point temperature of
the interior air. Under this design approach assume steady state heat transfer,
interior air at a temperature of 70 degrees F (21 degrees C), at a relative
humidity specified in Table 1 and exterior air at a temperature that is equal to
the average outdoor temperature for the location during the coldest three
months of the year (e.g. December, January and February).
4. Zone 5 requires a Class III (or lower) vapor retarder on the interior surface of
insulation in insulated wall and floor assemblies where the permeance of the
exterior sheathing is greater than 1.0 perm as tested by Test Method B (the
“wet cup” method) of ASTM E-96).
5. Zone 6 and Zone 7 require a Class II (or lower) vapor retarder on the interior
surface of insulation in insulated wall and floor assemblies where the
permeance of the exterior sheathing is greater than 1.0 perm as tested by Test
Method B (the “wet cup” method) of ASTM E-96).
6. Zone 5, Zone 6 and Zone 7 require a Class II (or lower) vapor retarder on the
interior surface of insulation in insulated wall and floor assemblies where the
permeance of the exterior sheathing/cladding assembly is less than or equal to
1.0 perm and greater than 0.1 perm as tested by Test Method B (the “wet cup”
method) of ASTM E-96).
7. Zone 5, Zone 6 and Zone 7 require a Class II (or lower) vapor retarder on the
interior surface of insulation in insulated wall and floor assemblies where the
permeance of the exterior sheathing is 0.1 perm or less as tested by Test
Method B (the “wet cup” method) of ASTM E-96) and the interior surface of
the exterior sheathing shall be maintained above the dew point temperature of
the interior air. Under this design approach assume steady state heat transfer,
interior air at a temperature of 70 degrees F (21 degrees C), at a relative
humidity specified in Table 1 and exterior air at a temperature that is equal to
the average outdoor temperature for the location during the coldest three
months of the year (e.g. December, January and February).
27. Understanding Vapor Barriers 27
TABLE 1: DESIGN CONDITIONS FOR STEADY STATE DESIGN PROCEEDURE – WALL
AND FLOOR ASSEMBLIES (not the actual service conditions for typical
residential occupancy – but the design conditions for the simple steady state
design procedure being used)
Zone 4 (marine) 40 percent RH @ 70 degrees F (Dew Point 45 degrees F)
Zone 5 30 percent RH @ 70 degrees F (Dew Point 37 degrees F)
Zone 6 25 percent RH @ 70 degrees F (Dew Point 32 degrees F)
Zone 7 20 percent RH @ 70 degrees F (Dew Point 28 degrees F)
TABLE 2: DESIGN CONDITIONS FOR STEADY STATE DESIGN PROCEEDURE – ROOF
AND ATTIC ASSEMBLIES (not the actual service conditions for typical residential
occupancy – but the design conditions for the simple steady state design
procedure being used)
Zone 5 35 percent RH @ 70 degrees F (Dew Point 39 degrees F)
Zone 6 30 percent RH @ 70 degrees F (Dew Point 37 degrees F)
Zone 7 25 percent RH @ 70 degrees F (Dew Point 32 degrees F)
8. Zone 5 requires a Class III (or lower) vapor retarder on the interior surface of
insulation in ventilated insulated roof or attic assemblies.
9. Zone 5, Zone 6 and Zone 7 require a Class II (or lower) vapor retarder on the
interior surface of insulation in unvented insulated roof or attic assemblies and
the condensing surface shall be maintained above the dew point temperature
of the interior air. The condensing surface is defined as either the interior
surface of the structural roof deck or the interior surface of an air-
impermeable insulation applied in direct contact to the underside/interior of
the structural roof deck. “Air-impermeable” is quantitatively defined by
ASTM E 283. Under this design approach assume steady state heat transfer,
interior air at a temperature of 70 degrees F (21 degrees C), at a relative humidity
specified in Table 2 and exterior air at a temperature that is equal to the
average outdoor temperature for the location during the coldest three months
of the year (e.g. December, January and February).
10. Zone 6 and Zone 7 require a Class II (or lower) vapor retarder on the interior
surface of insulation in ventilated insulated roof or attic assemblies.
11. Concrete slab floors in ground contact are required to have a Class I vapor
retarder below the slab in direct contact with the slab or rigid insulation
having a thermal resistance of at least R-5 below the slab in direct contact with
the slab.
28. 28 Building Science Digest 106
TABLE 3: SUMMARY OF RECOMMENDATIONS FOR VAPOR RETARDERS ON THE
INTERIOR OF WALL ASSEMBLIES
Wall Assembly Wall Assembly Wall Assembly
Exterior Sheathing Exterior Sheathing Assembly
(Greater than 1.0 perm) (Less than or equal 1.0
perm, and greater than
0.1 perm)
(Less than or equal 0.1
perm)
Zone
1 not required not required not required
2 not required not required not required
3 not required not required not required
4 (not marine) Class III Class III Class III
4 (marine) Class III Class II Class III*
5 Class III Class II Class II*
6 Class II Class II Class II*
7 Class II Class II Class II*
* Additionally, the interior surface of the exterior sheathing shall be
maintained above the dew point temperature of the interior air (see
Table 1).
What This Means From A Practical Perspective
Polyethylene is a Class I vapor retarder. A kraft faced fiberglass batt is a Class II vapor
retarder. Latex painted gypsum board (one coat of latex paint) is a Class III vapor
retarder.
Plywood sheathing and oriented strand board (OSB) have perm values of greater than
1 perm when using the wet cup test. Similarly for exterior gypsum sheathing or
fiberboard sheathing.
Extruded polystyrene of 1 inch thick or thicker has a perm value of 1.0 perm or less.
Film faced extruded polystyrenes of 1/2 inch thickness that have perforated facings
have perm values of greater than 1 perm. Non-perforated foil and polypropylene
faced rigid insulations have perm values of less than 0.1 perms.
Three-coat hard-coat stucco installed over two layers of Type D asphalt saturated kraft
paper and OSB has a combined perm value of less than 1.0 under a wet cup test.
Therefore the sheathing/cladding assembly is less than or equal to 1.0 as tested by Test
Method B of ASTM E-96.
Foil-faced isocyanurate 1/2 thick (R 3.5) installed over a 2x4 frame wall meets
requirement #9 in Chicago. Therefore, a kraft-faced batt (Class II vapor retarder) is
required on the interior of this assembly.
29. Understanding Vapor Barriers 29
Foil-faced isocyanurate 1 inch thick (R 6) installed over a 2x6 frame wall (R 19) meets
requirement #9 in Minneapolis. Therefore, a kraft-faced batt (Class II vapor retarder)
is required on the interior of this assembly.
In Chicago where plywood or OSB exterior sheathing is used, an unfaced fiberglass
batt can be installed within the wall cavity and gypsum board painted with latex paint
(Class III vapor retarder) is required on the interior of this assembly. If this assembly
is moved to Minneapolis, a Class II vapor retarder is required on the interior (a kraft
paper faced fiberglass batt).
References
Briggs, R.S., Lucas, R.G., and Taylor, T.; “Climate Classification for Building Energy
Codes and Standards: Part 1 – Development Process,” Technical & Symposium Papers,
ASHRAE Winter Meeting, Chicago, IL, January, 2003.
Briggs, R.S., Lucas, R.G., and Taylor, T.; “Climate Classification for Building Energy
Codes and Standards: Part 2 – Zone Definitions, Maps and Comparisons,” Technical
& Symposium Papers, ASHRAE Winter Meeting, Chicago, IL, January, 2003.
Kunzel, H.M.; WUFI: PC Program for Calculating the Coupled Heat and Moisture Transfer in
Building Components; Fraunhofer Institute for Building Physics, Holzkirchen, Germany,
1999.