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This Online Learning Seminar is available through a professional courtesy provided by: Moisture Management In Sidewall Construction Getting Started Click on the start button to begin this course • START • Pressure-equalized rainscreen wall system design for light-frame construction. Course #BOI 101 / Learning Unit(s): 1 -HS&W / Provider J 624 © 2003 Benjamin Obdyke Slide 1 of 24

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction MOISTURE MANAGEMENT IN SIDEWALL CONSTRUCTION Presented By: Ned Trautman Benjamin Obdyke Incorporated 199 Precision Drive Horsham, PA 19044 Description: Pressure-equalized rainscreen wall system design for light frame construction MCE Info: Contact your respective governmental licensing & regulatory agency. Expiration date: (1 year from AIA Accreditation) © 2003 Benjamin Obdyke 2

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction LEARNING OBJECTIVES • Recognize how moisture infiltrates the building skin through side wall conditions. • Understand the implications of water infiltration into the building. • Determine appropriate ways to employ rain screen principles for a variety of cladding systems. © 2003 Benjamin Obdyke 3

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction AN INDUSTRY PERSPECTIVE “The fundamental function of the building envelope is its separation of the outside and the inside environments so that indoor conditions can be controlled to meet many requirements (for example, comfort and energy efficiency). The design and construction of durable, efficient walls requires consideration of climate loads to which these building components will be exposed. A wall assembly that is trouble-free in one area of the country may not perform adequately in another. This is because although the building physics do not change, the heat, air and moisture control strategies may need to integrate different levels of redundancy for different climate conditions. The severity of the climate for a building site cannot be changed, but it needs to be integrated in the design of the wall assemblies. Understanding the climate loads acting on building components is an important step towards effective design of moisture management strategies”. (1) Cornick, S. and Rousseau, M. Z. , “Understanding the Severity of Climate Loads for Moisture-related Design of Walls”, IRC Building Science Insight 2003 Seminar Series, Toronto, CA, Oct. 2003, pp. 1 © 2003 Benjamin Obdyke 4

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction HOW DOES MOISTURE INFILTRATE THE BUILDING • High Humidity / Extreme Temperatures – Moisture vapor (“vapor- drive”) from the interior can pass through the shear wall condensing on the cold, outer surface. * “Dry to the outside” – outward vapor drive- in northern climates. – Positive pressure is created by air conditioned space. © 2003 Benjamin Obdyke 5

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction HOW DOES MOISTURE INFILTRATE THE BUILDING • Wind driven rain from the exterior can be forced into small penetrations in the cladding materials at joints, laps, hose-bibs, vents, utility cut-outs, nail holes, etc. © 2003 Benjamin Obdyke 6

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction WIND & RAIN ACTING TOGETHER CAUSE WATER INFILTRATION • Wind can blow the rain sometimes horizontally into cracks and holes in the exterior walls. • Wind blowing around the building can create a negative pressure within the wall assembly that siphons water into the assembly. • . “Reservoir” type claddings (hygroscopic) are especially sensitive to this phenomena © 2003 Benjamin Obdyke 7

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction WHAT ARE THE RESULTS OF MOISTURE INFILTRATION • • Exterior Surfaces Deteriorate Shortened service life of paints & stains (discoloration & peeling) Extractive bleed of pine & cedar resins Surfactant migration onto WRB © 2003 Benjamin Obdyke 8

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction WHAT ARE THE RESULTS OF MOISTURE INFILTRATION • Structural Damage – Water can also undermine the structural integrity of a building, causing an unsafe environment to work and live in. © 2003 Benjamin Obdyke 9

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction WHAT ARE THE RESULTS OF MOISTURE INFILTRATION • Mold – Mildew – Rot – Mold and Mildew spores exist in the environment. – Wet wood and gypsum products create a food source for the mold and mildew to grow. – As mold and mildew grow they cause the wall system to rot. – Interior mold and mildew create a condition called “sick building syndrome” that can be a health hazard to people with allergies. © 2003 Benjamin Obdyke 12

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction PRIMER: WHAT MAKES MOLD? • “The way to control indoor mold growth is to control MOISTURE”. USA Today, June 20, 2002 • “ 90% of all mold cases are related to WATER leaking through exterior finishes” BUILDER Magazine, May, 2002 © 2003 Benjamin Obdyke 13

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction MOISTURE MANAGEMENT METHODS ► Durability – Choice of quality construction materials is a significant factor in the long-term performance & overall success of the wall assembly. ►Deflection – Use architectural elements to keep water from entering wall system. ►Drying – Wall assembly that promotes water evaporation rather than penetration and provides a mechanism whereby the rate of drying exceeds the rate of wetting. ►Drainage – Rain screen type assemblies used to remove water from system. © 2003 Benjamin Obdyke 17

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction RAINSCREEN TECHNOLOGY • WHERE RAINSCREENS CAME FROM Originally developed for use in masonry construction, a rainscreen is a pressure equalized airspace between the structural envelope and the exterior cladding that promotes drainage of moisture from the assembly. Rainscreens were originally designed to not only “drain the rain” but help “TAME THE RAIN” by controlling the powerful RAIN forces wetting the wall. © 2003 Benjamin Obdyke 18

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction RAINSCREEN TECHNOLOGY • WHY USE A RAINSCREEN? The notion of a “face-sealed” assembly as defined in ASTM E 2128 whereby “the exterior surfaces are relied upon as the only barrier” (to water entry) has been replaced by the realization that water is going to by-pass the exterior cladding and therefore must be intentionally addressed with a “forgiving” assembly that manages the water. © 2003 Benjamin Obdyke 19

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction PRESSURE EQUALIZED RAINSCREEN WALL PRINCIPLES • HOW RAINSCREENS WORK The difference in air pressures across the exterior cladding is a significant force which causes infiltration of air and water on windward facades. The equalization of this pressure difference neutralizes the forces that draw water into the assembly. In addition, the airspace (minimum 1/8”) de-couples most of the cladding from the shear-wall reducing the capillary action of bulk water bridging onto the building paper. © 2003 Benjamin Obdyke 20

• About the Sponsor • About the Instructor • Seminar Discussion Forum Moisture Management in Construction WHERE TO USE RAINSCREENS “ Moisture management strategies are recommended in all climate regions, and are essential where average rainfall exceeds 20 inches”. Joe Lstiburek, Ph. D, PEng Building Science Corporation © 2003 Benjamin Obdyke 21

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction TRADITIONAL RAINSCREEN ASSEMBLY • The traditional way of creating a rainscreen wall: – Place lathe strips or 1 x P. T. dimensional lumber, vertically at 8”, 12”, 16”or 24”centers. – Attach cladding to the wood strips Disadvantages of Traditional Rainscreen Assembly: ü Labor intensive and hard to detail around penetrations. ( $1. 25 – 2. 00) ü Create hot-spots and thermal bridging along stud locations. ü Ballooning of house-wrap leads to reduced air movement in intended rainscreen cavity. ü Cupping & bowing of furring strips leads to premature failure of coating. ü Wood-to-wood contact traps moisture, supports growth of mold and causes “ghosting” or vertical telegraphing of furring locations to outside surfaces. ü Inconsistent performance. © 2003 Benjamin Obdyke 22

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction IMPROVEMENTS IN MOISTURE MANAGEMENT METHODS • “Void space technology” utilizes a 3 -dimensional plastic matrix (i. e. HOME SLICKER) SLICKER to create a vented continuous rainscreen that offers accelerated drying and enhanced drainage characteristics over traditional methods. The benefit of this technology is improved performance and cost-effectiveness. © 2003 Benjamin Obdyke 24

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction WHAT IS HOME SLICKER™ ? • HOME SLICKER is a patented “moisture eliminating rainscreen” that provides a continuous, vertically channeled air circulation AND water drainage plane between the cladding and the structural envelope. * CSI Manu-spec © 2003 Benjamin Obdyke 25

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction WHAT IS HOME SLICKER? • Provides ¼” airspace • Three-dimensional plastic matrix • Not affected by heat or cold • Not affected by UV • Lightweight 7. 2 per roll • Covers 150 Sf • 50 year limited warranty © 2003 Benjamin Obdyke 26

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction MOISTURE MANAGEMENT METHODS • A vented and continuous rainscreen barrier may be placed behind many exterior finish materials including: – – – – Wood Siding Stucco EIFS Cement Fiber Sidings Hardboard Siding Stone Veneer Shingles Vinyl Siding © 2003 Benjamin Obdyke 27

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction MOISTURE MANAGEMENT METHODS • Top and bottom of vented rainscreen barrier cavity must be ventilated to allow moisture to escape and to equalize the pressure in the drainage cavity. © 2003 Benjamin Obdyke 28

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction MOISTURE MANAGEMENT METHODS • Detailing around penetrations is critical to the success of any vented rain screen barrier system. • Flashing the window or door assembly into the moisture barrier system must be clearly detailed on the drawings and coordinated with the vented rain screen barrier system. © 2003 Benjamin Obdyke 29

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction Proof Statements: • “The use of rain-screen assemblies will eliminate the driving force that causes water to leak into the wall” APA-The Engineered Wood Association “Build a Better Home” (2001) • “Rain-screens offer exceptional value to design professionals seeking liability protection, builders wanting to avoid callbacks, and homeowners looking for comfort”. NAHB Research Center “Deterring rainwater intrusion into walls” (2005) • “HOME SLICKER was more cost-effective* and offered a better performance profile relative to drainage & drying compared to the alternative of strapping the wall out. ” APA-The Engineered Wood Association “The Engineered Wood Connection” (2005) (* $0. 50 -0. 75 installed cost) © 2003 Benjamin Obdyke 30

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction HOME SLICKER VALUE PROPOSITION • Working to PRESERVE and PROTECT the cladding and the shear-wall, HOME SLICKER offers a unique and enhanced functionality to the a wall assembly benefiting all participants in the transaction : ► Architect ► Builder ► Contractor ► Distributor ► End-user © 2003 Benjamin Obdyke 31

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction The ARCHITECT • As a ventilated rainscreen, HOME SLICKER neutralizes the ability of the wall assembly to siphon water in behind the cladding • HOME SLICKER allows enough air space to eliminate capillary action • HOME SLICKER prevents contact of wood cladding with WRB to avoid surfactant damage • As a manufactured product, HOME SLICKER provides the assurance that the intended rainscreen assembly (as drawn) installed properly © 2003 Benjamin Obdyke is 32

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction The BUILDER • HOME SLICKER is a cost-effective means of providing a uniform rainscreen assembly that offers continuous ventilation and drainage to the exterior wall assembly (~$0. 50 – 0. 75 / Sf installed cost) • HOME SLICKER helps protect against unwanted liability claims • HOME SLICKER helps to eliminate costly call-backs © 2003 Benjamin Obdyke 33

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction The CONTRACTOR • HOME SLICKER is simple & easy to install • HOME SLICKER speeds installation time of rain-screen assembly when compared to furring strips © 2003 Benjamin Obdyke 34

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction THE DISTRIBUTOR • As a VALUE-ADDED product, HOME SLICKER enhances a strategic objective that seeks to differentiate the distributor from competitors offering only commodity products • HOME SLICKER extends a product group yielding a more comprehensive moisture management solution • HOME SLICKER supports UP-SELL initiatives with allied product bundling configurations © 2003 Benjamin Obdyke 35

• About the Instructor • About the Sponsor • Seminar Discussion Forum Moisture Management in Construction The END-USER ( Home Owner) • HOME SLICKER offers a high degree of confidence that Health & Safety issues (i. e. mold) are being systematically addressed as the result of Home Slicker’s inclusion in an effective moisture management strategy • HOME SLICKER helps to promote the long term service-life of paints & stains © 2003 Benjamin Obdyke 36