*Trademark of The Dow Chemical Company A business unit of The Dow Chemical Company and its subsidiaries Copyright 2003 The Dow Chemical Company.

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2 Dow Chemical is a Registered Provider with The American Institute of Architects Continuing Education Systems. Credit earned on completion of this program will be reported to CES Records for AIA members. Certificates of Completion for non-aia members available on request. This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation. Thank you!

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4 This presentation is protected by US and International copyright laws. Reproduction, distribution, display and use of the presentation without written permission of the speaker is prohibited. The Dow Chemical Company 2004

5 Understanding the key issues in Proper Wall Design based on Building Science fundamentals. Framing & cavities Understanding Insulation Basic frame wall physics Air infiltration The drainage plane Key problems with frame walls

6 !"#$# Energy Moisture The cost of energy continues to escalate and moisture issues are growing with every failure. Contractors can build or remodel the right way and extract value.

7 % The cost of energy continues to escalate. Energy efficiency is of growing concern. Cost of Energy Energy bill for an average family in the U.S. has increased 25% since Americans spend $131 billion each year on household energy costs. Home heating and cooling payments are the single largest payment for families after the mortgage. Low-income families spend a quarter of their household income on winter heating bills. Over Time

8 #&' Build on our knowledge. The solution is Building Science...

9 $$"#$ Good materials and good workmanship no longer constitute a high quality home we must now understand how homes work. Joseph Lstiburek, P. Eng. Building Science Corporation

10 (' ) " We will cover the following: Framing and cavities. Understanding insulation. Basic frame wall physics. Air infiltration. The drainage plane. Key problems with frame walls.

11 (' # Wood Framing The framing creates the structure of the house. Cavities are a byproduct of the structure. Cavity Insulation

12 $$# What is Insulation? Is it... A. The glass fibers in fiberglass insulation. B. The paper fibers in cellulose insulation. C. The plastic resin in rigid foam insulation. D. All of the above. E. The trapped air in any carrier material.

13 $$# Insulation is basically air. Carrier materials create compartments to trap air. Generally, the more compartments of air across the same span, the greater the thermal resistance. If insulation is compressed, its R-value is reduced. If moisture takes over the compartments of air, its R-value is reduced. If the air is forced to move from air infiltration or convection, then the insulation is less efficient.

14 $$# R-values of various products: 6 R-Value (per inch) Wood studs OSB Gypsum Wet spray cellulose Fiber glass XPS rigid foam ISO rigid foam

15 "(' ) & Warm migrates toward cold. When heating, warm indoor air migrates toward a cold exterior. When cooling, warm exterior air migrates toward an air conditioned interior. More moisture moves toward less moisture. Nature tries to equalize. Warmer air holds more moisture while cooler air is drier. The vapor drive will typically be from warmer moisture toward cooler drier.

16 % Causes of air infiltration: Penetrations (gaps/cracks) in the home envelope. Can be direct to conditioned air space or into insulation cavities. Impact of air infiltration: Significant energy loss. Reduces efficiency of cavity insulation by forcing air movement. Causes greatest transfer of moisture vapor (versus diffusion).

17 % Common air infiltration materials. #15 felt (asphalt-impregnated building paper) Housewraps Insulated sheathing Extruded polystyrene foam insulation Polyisocyanurate foam insulation

18 & The drainage plane is The exterior water barrier for your wall. Exterior finishes such as siding and brick are known as the primary weather barrier, but you should know they all leak. The primary causes of water penetrating behind siding and brick are: Wind-driven rain Dew point condensation

19 & Common drainage plane materials. #15 felt (asphalt-impregnated building paper) Moisture-resistant housewraps Insulated sheathing Extruded polystyrene foam insulation Polyisocyanurate foam insulation (impermeable facers)

20 (' ) # Key problems with wood frame walls today: Thermal bridging through wood framing. Factors limiting the use of cavity insulation. Wood framing (more than 16 centers) Plumbing Heating and cooling ductwork Electrical wiring, outlets and junctions Wall cavity convection currents. Dew-point condensation.

21 ' "$* #$ What is Thermal Bridging? Energy loss through wood framing.

22 ' "$* #$ Wood framing is not a good insulator. Heated and cooled air is bridged through uninsulated wood framing.

23 ' "$* #$ Note the surface area of the wood without additional framing for windows and doors.

24 ' "$* #$ Remove the wood framing and ask... Is this wall insulated?

25 ' "$* #$ Now it is! A layer of insulated sheathing covers the entire opaque wall, including the framing.

26 ' "$* #$ 55% of heat loss in typical homes comes from air infiltration (38%) and wood frame walls (17%). Without insulated sheathing, a quarter of your walls are not insulated! of the Surface Area is Wood! On a square house, it s the equivalent of one whole wall!

27 ' "$* #$ Thermal bridging is significant in both heating and cooling climates. Heated outside air Heated inside air If you re heating in the winter or cooling in the summer, stud loss means energy loss. Wood Stud

28 ' "$* #$ Insulated sheathings cover everything, including the wood framing. Insulated sheathing will enhance the efficiency of the entire wall system. Heated outside air Heated inside air Wood Stud

29 (' ) # Key problems with wood frame walls today: Thermal bridging through wood framing. Factors limiting the use of cavity insulation. Wood framing (more than you think) Plumbing Heating and cooling ductwork Electrical wiring, outlets and junctions Wall cavity convection currents. Dew-point condensation.

30 # ' $ Heating and cooling loss occurs on outside walls anywhere cavity insulation doesn t cover. Window Oriented Interior Plumbing Stud Jack Heating/cooling Electrical Buck Warm Cripplers Actual Air Exterior Cold Cavity Wood barrier loss studs outside support inside studs heating insulation gypsum vapor frame siding strand to junction vent (housewrap) to support retarder for pipe & board supply 16 header cooling wall & centers wiring window partition header (OSB) duct losses! sill

31 # ' $ Structural requirements often times completely restrict the use of cavity insulation. Here it is! None here... None here... No cavity insulation here...

32 # ' $ Worse yet, there are open pockets created by structural designs that typically don t get filled. Note pieshaped gap! Top View of 45º corner

33 # ' $ Insulated sheathings are the first line of thermal defense and the only consistent layer of thermal protection for a home.

34 # ' $ Framing reduces cavity insulation. Framing mistakes further reduce cavity insulation.

35 # ' $ Wood framing occurs far more than every 16 or 24 inches on center. Everywhere there s wood framing, there can t be cavity insulation. Note additional wood framing beyond 16 centers.

36 # ' $ Plumbing on the exterior walls further limits the use and effectiveness of cavity insulation. How efficient will the cavity insulation be in these areas?

37 # ' $ HVAC ductwork on the perimeter wall also limits the use of cavity insulation. Note poor installation of cavity insulation.

38 # ' $ HVAC ductwork on the perimeter wall also limits the use of cavity insulation. Top view of this area shows deficiencies.

39 # ' $ Heating and cooling losses are more dramatic because supply ducts contain conditioned air. HVAC Supply Duct Little or no thermal protection between supply duct and outside of wall. When cooling the interior, this could cause moisture problems.

40 # ' $ Insulated sheathings span the entire wall surface to provide a wall s only consistent thickness of thermal protection. HVAC Supply Duct

41 # ' $ The only consistent thing about batt insulation is the inconsistent installation.

42 # ' $ The only consistent thing about batt insulation is the inconsistent installation. Note the gaps and compressions even on standard cavity widths.

43 R-7 R-4 R-11 # R-8 ' $ Insulated sheathings enhance the cavity insulation and makes it work better. R-2 R-6 R-9 R-17 R-7 R-12 R-14 R-10 R-19 Batt R-5 Dow R-5 R-5 R-5 R-5

44 # ' $ Even wet spray cellulose can t insulate the wood framing and it s also limited by electrical, plumbing and HVAC ducts.

45 # ' $ Though wet spray cellulose can provide a better fill, gaps and voids still occur.

46 # ' $ Insulated sheathings span the entire wall surface to provide the only consistent thickness of thermal protection.

47 # ' $ Wood studs occur far more than every 16. Header Window sill Red outlines are 16 centers Heating/cooling supply duct Plumbing vent pipe Jack stud - header support Buck - interior wall support Crippler - sill support Electrical box and wiring

48 # ' $ Is this wall insulated? Window The yellow areas show how little of the opaque wall is covered by cavity insulation.

49 # ' $ Window A layer of Insulated sheathing covers the entire opaque wall area, insulating wood framing and areas not covered by the cavity insulation.

50 (' ) # Key problems with wood frame walls today: Thermal bridging through wood framing. Factors limiting the use of cavity insulation. Wood framing (more than 16 centers) Plumbing Heating and cooling ductwork Electrical wiring, outlets and junctions Wall cavity convection currents. Dew-point condensation.

51 ) Warm Side Cold Side What is cavity convection? Energy loss through movement or looping of heated and cooled air.

52 ) Air movement in the cavity reduces insulation efficiency, contributing to energy loss. Warm Side Air near the inside wall is heated and rises. Cold Side Air near the outside wall is cooled and falls. Cold Side Air near the inside wall is cooled and falls. Warm Side Air near the outside wall is heated and rises. Cold climate Hot climate Trapped air (insulation) becomes less efficient with movement.

53 ) Insulated sheathings will warm-up the exterior side of the cavity and improve the thermal efficiency of the entire wall. In a warm or cold climate, insulated sheathings moderate the cavity temperature and reduce convection currents, making the cavity insulation more effective.

54 (' ) # Key problems with wood frame walls today: Thermal bridging through wood framing. Factors limiting the use of cavity insulation. Wood framing (more than 16 centers) Plumbing Heating and cooling ductwork Electrical wiring, outlets and junctions Wall cavity convection currents. Dew-point condensation.

55 #&' Moisture is the #1 enemy of most building materials. It only takes a small amount of consistent moisture to lead to: Reduced R-value Deterioration / Rot Mold & mildew

56 +*&$ What is dew-point condensation? The point when water in a gas form (vapor) changes to liquid -- a factor of temperature and humidity.

57 +*&$ A dew-point calculation chart shows all. % Relative Humidity Temperature F Temp + 35% RH = 40 Dew-Point Temp

58 +*&$ A dew-point analysis can show what the wetting potential may be for certain wall systems under specific climate conditions. Dew-Point Theory predicts condensation in a system at any point where the actual and dew-point temperature lines cross.

59 +*&$ Dew-Point Analysis: Winter, 2x4, R-13 batt, 7/16 OSB Temperature (Degrees F) ABC D E F G H Distance From Interior (in Inches) Actual Temp Dew-Point Temp Conditions: Interior Exterior Temperature Humidity A. Interior air film B. Latex paint 2 coat C. Drywall 1/2 inch D. Kraft-facer for batt E. R-13 fiberglass batt F. OSB 7/16 inch G. Vinyl siding H. Outside air film NOTICE: This calculation is based on the theory of water vapor migration presented in the ASHRAE 93 Fundamentals *Trademark Handbood. of The Actual Dow performance Chemical Company may vary depending upon air infiltration, workmanship and building materials. Since the A information business unit is of provided The Dow without Chemical charge, Company The and Dow its subsidiaries Chemical Company assume no obligation or liability for its use.

60 +*&$ Dew-Point Analysis: Winter, 2x4, R-13 batt, 3/4 DURAMATE Plus Temperature (Degrees F) ABC D E F G H Distance From Interior (in Inches) Actual Temp Dew-Point Temp Conditions: Interior Exterior Temperature Humidity A. Interior air film B. Latex paint 2 coat C. Drywall 1/2 inch D. Kraft-facer for batt E. R-13 fiberglass batt F. DURAMATE Plus G. Vinyl siding H. Outside air film NOTICE: This calculation is based on the theory of water vapor migration presented in the ASHRAE 93 Fundamentals *Trademark Handbood. of The Actual Dow performance Chemical Company may vary depending upon air infiltration, workmanship and building materials. Since the A information business unit is of provided The Dow without Chemical charge, Company The and Dow its subsidiaries Chemical Company assume no obligation or liability for its use.

61 +*&$ If the surface of the can is colder than the dew-point temperature, then water vapor will condense on its surface just as it will in your walls, unless you address it.

62 +*&$ Hot climate Cool Interior Warm Interior Vapor drive outside-in Warm Exterior Cool Exterior Just like on the can, if either surface of the wall is colder than the dew-point temp, vapor in the wall will condense into liquid water. Vapor drive inside-out Cold climate

63 +*&$ Condensation forms in very small droplets. Pressure differences, surface tension and capillary forces cause water droplets to be absorbed into wood sheathing, studs and cavity insulation. But if you warm up the surface, you don t allow the vapor to condense into water droplets.

64 +*&$ Empty part of the can. No condensation. Why? See the line? Warm the cavity of the can above the dew-point temp and eliminate the condensation.

65 +*&$ Much like a can insulator, a layer of rigid insulation serves to reduce the potential for dew-point condensation.

66 +*&$ An appropriate thickness of insulated sheathing can warm the wall cavity above the dew-point temperature. Let us help you select the right thickness based on dew point analysis. Insulated sheathing moderates the temperature in the cavity to reduce the potential for dew-point condensation.

67 ' ' Moisture issues are growing with every failure. Builders can address energy and moisture issues and extract value with Insulated sheathing.

68 "' Knowing what you now know, why wouldn t you use insulated sheathing to enhance your wall system performance?

69 "' New construction or remodeling The science and benefits are the same.

70 "' Insulated sheathings enhance the performance of the entire wall system. For instance, extruded polystyrene provides an R-value of 5 per inch, but by Insulating the wood framing. Insulating the mechanicals in the cavities. Insulating the exterior wall to reduce convection currents in the cavity insulation. Insulating the exterior wall to reduce dew point condensation. Insulated sheathing will return more than it offers in pure R value - it makes the whole wall system perform better.

71 "' You can t drink coffee from a Styrofoam cup! Expanded polystyrene foam versus extruded polystyrene and polyisocyanurate foams... There are differences.

72 ,-#. This concludes the American Institute of Architects Continuing Education System Program. Copyright 2002 The Dow Chemical Company All rights reserved