Project Overcoat - An Exploration of Exterior Insulation Strategies for 1-1/2-Story Roof Applications in Cold Climates

Ojczyk, Cindy¹  Mosiman, Garrett¹  Huelman, Pat² 

[1] NorthernSTAR Building America Partnership, St. Paul, MN (United States);NorthernSTAR Building America Partnership, St. Paul, MN (Uni

关键词: RIGID FOAM;    EXTERIOR INSULATION;    ICE DAM;    HIGH R ROOF;    FULLY VENTED PITCHED ATTIC ASSEMBLY;    SPRAY FOAM EXTERIOR;    SIP ROOF RETROFIT;    EXTERNAL INSULATION;    ROOF MEMBRANE;    Buildings;   

DOI  :  10.2172/1079099
RP-ID  :  DOE/GO--102013-3751
PID  :  OSTI ID: 1079099
Others  :  Other: KNDJ-0-40338-00

学科分类：能源（综合）

美国|英语

来源: SciTech Connect

【 摘 要 】

The development of an alternative method to interior-applied insulation strategies or exterior applied 'band-aids' such as heat tapes and ice belts may help reduce energy needs of millions of 1-1/2 story homes while reducing the risk of ice dam formation. A potential strategy for energy improvement of the roof is borrowed from new construction best practices: Here an 'overcoat' of a continuous air, moisture, and thermal barrier is applied on the outside of the roof structure for improved overall performance. The continuous insulation of this approach facilitates a reduction in thermal bridging which could further reduce energy consumption and bring existing homes closer to meeting the Building America goals for energy reduction. Research favors an exterior approach to deep energy retrofits and ice dam prevention in existing homes. The greatest amount of research focuses on whole house deep energy retrofits leaving a void in roof-only applications. The research is also void of data supporting the hygrothermal performance, durability, constructability, and cost of roof-only exterior overcoat strategies. Yet, contractors interviewed for this report indicate an understanding that exterior approaches are most promising for mitigating ice dams and energy loss and are able to sell these strategies to homeowners.