Uploaded December 2024 | Updated September 2026, 3 weeks ago
This video is the third in a short series in which we assess and improve the energy performance of a 20' x 20' cabin under construction in Fairbanks, Alaska, in IECC Climate Zone 8. The initial builder of the cabin made a number of choices that were less than ideal for Fairbanks winters. The property was sold before the cabin was completed, and we’re working with the new owner to insulate and otherwise improve the cabin to maximize its energy efficiency on a tight budget.
In this video we evaluate and make improvements to the cabin roof. The roof was unfortunately built without enough room to fit adequate insulation for the local climate. As a result, the roof is thermally inefficient and, due to its excessive heat loss, is also highly susceptible to ice dams. This roof underscores two common mistakes people make when stick framing cathedral ceilings in cold climates. First, the builder didn’t install deep enough rafters to hold a climate-appropriate amount of insulation and still provide a minimum of 1 1/2" of continuous vent space. Second, they used a framing method (in this case, collar ties) that makes it very difficult to air seal the transition from walls to roof. We successfully mitigate both of these problems in the video.
However, it’s important to note that the best way to address these mistakes is not to make them in the first place. Linked below please find two videos that cover other methods to frame and insulate a high- performance cathedral roof in climate zone 8, as well as a video detailing a vapor retarder replacement of an older cathedral roof which was not furred inwards or air sealed properly.
Cold Climate Building Techniques and Concepts: Building a cathedral roof
youtube.com/watch?v=mOK-D3rsomw
Cold Climate Building Techniques and Concepts: Vapor retarder
youtube.com/watch?v=R8RMR-e-LlE
Replacing an existing ceiling vapor retarder:
youtube.com/watch?v=yM_OK08QpCM
A future video in this series will detail energy efficiency improvements to the floors, and there’ll also be a brief bonus video about the cabin’s foundation. We’ll conclude with a review of an energy audit that will quantify how the changes made affect energy performance, and we'll also discuss how the improvements impact building durability and comfort.
We welcome questions and discussion in the comments and you can also reach us at info@cchrc.org.
CCHRC website: cchrc.org
CCHRC YouTube channel: @coldclimatehousing
We gratefully acknowledge the cooperation and assistance of Vertex Insulation, Inc. in the production of the videos in this series. vertexinsulation.com
Music: "Motivational inspiring music" by Alexander Blu from orangefreesounds.com/. The song is permitted for non-commercial use under license “Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)”
This video is the third in a short series in which we assess and improve the energy performance of a 20' x 20' cabin under construction in Fairbanks, Alaska, in IECC Climate Zone 8. The initial builder of the cabin made a number of choices that were less than ideal for Fairbanks winters. The property was sold before the cabin was completed, and we’re working with the new owner to insulate and otherwise improve the cabin to maximize its energy efficiency on a tight budget.
In this video we evaluate and make improvements to the cabin roof. The roof was unfortunately built without enough room to fit adequate insulation for the local climate. As a result, the roof is thermally inefficient and, due to its excessive heat loss, is also highly susceptible to ice dams. This roof underscores two common mistakes people make when stick framing cathedral ceilings in cold climates. First, the builder didn’t install deep enough rafters to hold a climate-appropriate amount of insulation and still provide a minimum of 1 1/2" of continuous vent space. Second, they used a framing method (in this case, collar ties) that makes it very difficult to air seal the transition from walls to roof. We successfully mitigate both of these problems in the video.
However, it’s important to note that the best way to address these mistakes is not to make them in the first place. Linked below please find two videos that cover other methods to frame and insulate a high- performance cathedral roof in climate zone 8, as well as a video detailing a vapor retarder replacement of an older cathedral roof which was not furred inwards or air sealed properly.
Cold Climate Building Techniques and Concepts: Building a cathedral roof
youtube.com/watch?v=mOK-D3rsomw
Cold Climate Building Techniques and Concepts: Vapor retarder
youtube.com/watch?v=R8RMR-e-LlE
Replacing an existing ceiling vapor retarder:
youtube.com/watch?v=yM_OK08QpCM
A future video in this series will detail energy efficiency improvements to the floors, and there’ll also be a brief bonus video about the cabin’s foundation. We’ll conclude with a review of an energy audit that will quantify how the changes made affect energy performance, and we'll also discuss how the improvements impact building durability and comfort.
We welcome questions and discussion in the comments and you can also reach us at info@cchrc.org.
CCHRC website: cchrc.org
CCHRC YouTube channel: @coldclimatehousing
We gratefully acknowledge the cooperation and assistance of Vertex Insulation, Inc. in the production of the videos in this series. vertexinsulation.com
Music: "Motivational inspiring music" by Alexander Blu from orangefreesounds.com/. The song is permitted for non-commercial use under license “Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)”
