Insulation a Guide for Contractors to Share with Homeowners

BUILDING TECHNOLOGIES PROGRAM VOLUME 17. BUILDING AMERICA BEST PRACTICES SERIES Energy Renovations Insulation A Guide for Contractors to Share with Homeowners PREPARED BY Pacific Northwest National Laboratory & Oak Ridge National Laboratory May 2012 R May 2012 • PNNL-20972 BUILDING AMERICA BEST PRACTICES SERIES Energy Renovations Volume 17: Insulation A Guide for Contractors to Share with Homeowners Prepared by Pacific Northwest National Laboratory Michael C. Baechler, Project Manager K. T. Adams, M. G. Hefty, and T. L. Gilbride and Oak Ridge National Laboratory Pat M. Love May 2012 Prepared for the U.S. Department of Energy Building America Program PNNL-20972 Pacific Northwest National Laboratory Richland, Washington 99352 Contract DE-AC05-76RLO 1830 This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor Battelle Memorial Institute, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or Battelle Memorial Institute. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. ENERGY RENOVATIONS INSULATION Preface R The U.S. Department of Energy recognizes the enormous potential that exists for improving the energy efficiency, safety, and comfort of existing American homes. This series of Energy Renovation Guides describes approaches for homeowners and builders working on You can learn more about Building America existing homes. and download additional copies of this document and others, including climate This guide will help contractors and homeowners identify ways to guides, best practices guides, research make their homes more comfortable, more energy efficient, and reports, and case studies, at healthier to live in. It also identifies the steps to take, with the help www.buildingamerica.gov. of a qualified home performance contractor, to increase their home’s To see the current list of Building America insulation, ensure healthy levels of ventilation, and prevent moisture research teams, go to www.eere.energy. problems. Contractors can use this document to explain the value of gov/buildings/building_america/ these insulation measures to their customers. The references in this research_teams.html. document provide further explanation of insulation techniques and technologies. Heating and cooling account for 50% to 70% of the energy used in the average American home (DOE 2008b). Heat gain or loss due to inadequate insulation is a leading cause of energy waste in most homes. Studies show that proper insulation and air sealing techniques can typically achieve whole-house energy savings of 10% to 20% over pre-retrofit energy usage (EPA 2011b). In older homes and homes with little or no insulation, savings may be much higher. These recommendations for improving insulation are based on the results of research and demonstration projects conducted by the U.S. Department of Energy’s Building America and Home Performance with ENERGY STAR, sponsored by the U.S. Environmental Protection Agency and DOE. Home Performance with ENERGY STAR offers a comprehensive, whole-house approach to improving the energy efficiency and comfort of existing homes and requires a test-in/test-out process. DOE’s Building America has worked with some of the nation’s leading building scientists and more than 600 production builders on more than 42,100 new homes. Building America’s research applies building science to the goal of achieving efficient, comfortable, healthy, and durable homes. May 2012 i i ENERGY RENOVATIONS INSULATION ii May 2012 ENERGY RENOVATIONS INSULATION Contents Preface .................................................................................................................... i 1.0 Introduction ......................................................................................................1 1.1 How to Use this Guide........................................................................................ 2 1.2 The Home Performance Energy Checkup ................................................................. 2 1.3 When to Get a Home Energy Checkup .................................................................... 3 2.0 Adding Insulation during Remodeling Projects – When, Where, and How Much .......................................................................... 5 2.1 When and Where to Add Insulation ....................................................................... 5 2.2 How Much Insulation to Add ................................................................................ 7 2.3 The Bottom Line: Is Adding Insulation Worth the Cost? ............................................... 11 3.0 Types of Insulation .......................................................................................... 13 3.1 Insulation Table Summary Tables ......................................................................... 13 3.2 Vapor Retarders .............................................................................................. 18 4.0 Insulation—Safety and Health Issues ............................................................... 19 4.1 Health and Safety Steps: Do These Before You Insulate .............................................. 19 4.2 Insulation Products: Health and Safety Concerns ......................................................22 5.0 How to Add Insulation .....................................................................................27 5.1 Insulating an Attic ...........................................................................................29 5.1.1 Preparing to Insulate an Attic ........................................................................29 5.1.2 Insulating a Vented Attic .............................................................................32 5.1.3 Insulating Unvented Attics ...........................................................................37 5.2 Insulating Flat Roofs and Vaulted Ceilings ..............................................................43 5.3 Insulating Exterior Walls ................................................................................... 44 5.3.1 Stud-Framed Walls: When to Insulate ............................................................. 44 5.3.2 Stud-Framed Walls: Adding Interior Cavity Insulation ...........................................47 5.3.3 Stud-Framed Walls: Adding Exterior Insulation ..................................................50 5.3.4 Masonry Walls: When and Where to Insulate ......................................................52 5.3.5 Masonry Walls: Adding Exterior Insulation .........................................................53 5.3.6 Masonry Walls: Adding Interior Insulation .........................................................53 5.4 Insulating a Crawlspace .....................................................................................55 5.4.1 Why Vents Should be Closed in Humid Climate Zones ...........................................57 5.4.2 Insulation for a Closed Crawlspace .................................................................57 5.4.3 How to Seal and Insulate a Crawlspace ............................................................58 5.4.4 Insulating a Crawlspace in Dry and Marine Climate Zones ....................................... 61 May 2012 iii iii ENERGY RENOVATIONS INSULATION 5.5 Insulating Basements .......................................................................................62 5.5.1 Moisture Control and Air Sealing ....................................................................63 5.5.2 Choosing the Best Approach for Insulating your Basement .....................................63 5.5.3 Preparing to Insulate your Basement ...............................................................67 5.5.4 Installing Insulation on the Interior of Basement Walls ...........................................69 5.5.5 Installing Insulation on the Exterior of Basement Walls ..........................................70 5.5.6 Installing Insulation on the Basement Ceiling...................................................... 71 5.5.7 Maintaining a Dry, Problem-free Basement .......................................................72 5.6 Insulating Concrete Floors .................................................................................72 5.6.1 Insulating the Surface of a Concrete Floor ........................................................73 5.6.3 Insulating the Perimeter of a Slab ...................................................................75 5.7 Insulating Ducts ..............................................................................................77 References ..................................................................................................... 81 Photo Credits ..................................................................................................85 Appendix A – How Insulation Works: Understanding Heat Flow and Air Pressure

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