top of page

The Changing Landscape of Residential Insulation


Inadequate Cavity Insulation

Move Away from Wall Cavity Only Residential Insulation


The common or standard residential home is built with exterior walls framed of wood studs, with the space between the studs filled with insulation as the only method to improve energy efficiency, this being cavity-only residential insulation. Moving away from wall cavity-only residential insulation practices is becoming increasingly advocated in building design and construction for a number of reasons. This approach promotes better overall energy efficiency, reduces thermal bridging, and enhances the durability of buildings.


The primary concern regarding wall studs in construction is thermal bridging, a process where materials with high conductivity allow heat to move through a building's structure, bypassing insulation and reducing its effectiveness. This can lead to energy wastage, increased heating and cooling costs, and potential issues such as condensation and mold growth. Of the many culprits found in a commonly built residence, exterior wall studs are typical culprits of thermal bridging due to their solid material and direct contact between the interior and exterior walls.


In stick-frame houses where vertical lumber is used to form exterior walls , the wood framing limits insulation capacity across the entire wall surface. Softwood lumber has R-1.25/inch insulation value, less than all types of insulations available today. Wood framing creates thermal bridges, reducing overall R-value significantly in a typical home. A 2x6 wall with R-19 fiberglass batts actually has R-12.8 whole-wall R-value (R-11 with poor installation), Bursting a fallacy, spray foam insulation can range from R-3.6 to R-3.9 which is marginally better than fiberglass batt, however it is still a cavity insulation method and subject to the same wall R-value performance loss as with fiberglass batts.


To mitigate thermal bridging caused by studs and cavity only residential insulation, various more modern techniques can be employed that reduce or eliminate the amount of thermal bridging components or sources used in the wall assembly.


Better Alternatives to Wall Cavity Systems


Exterior Insulation and Finishing Systems (EIFS):

EIFS involves placing insulation on the outside of the building envelope, which helps to reduce thermal bridging and increase overall energy efficiency. This method can provide continuous insulation, which is not interrupted by the building's framing, thus improving the building's thermal performance .


Insulated Concrete Forms (ICFs):

ICFs are forms for concrete that stay in place as permanent building insulation for energy-efficient, cast-in-place, reinforced concrete walls. ICF construction combines the strength and durability of concrete with the energy efficiency of rigid insulation. This method helps to create a high-performance building envelope that significantly reduces energy loss .


Structural Insulated Panels (SIPs):

SIPs consist of an insulating foam core sandwiched between two structural facings, typically oriented strand board (OSB). SIPs provide excellent and uniform insulation compared to traditional framing, and they can be used for walls, floors, and roofs, creating a very airtight and energy-efficient building envelope .


Continuous Insulation (CI):

CI involves applying insulation continuously across all structural members without thermal bridges other than fasteners and service openings. This approach is beneficial in reducing energy loss through the building envelope and is often used in combination with other insulation methods like EIFS .


Green Roofs and Insulated Roof Panels:

Incorporating insulation in roofing systems, such as using insulated roof panels or green roofs, can significantly reduce heat loss through the roof, which is a major area of energy loss in buildings. Green roofs provide additional benefits like reducing urban heat islands and managing stormwater runoff .


Conclusion

Although still common and arguably the standard, traditional stick framed approach for residential exterior walls has fallen behind in todays landscape of construction methods and techniques. However with the right design and moving away from wall cavity-only residential insulation practices, framed walls can still rise to better levels of R-value and performance.


Moving away from wall cavity-only insulation practices requires a holistic approach to building design, focusing on the entire building envelope rather than just the walls. This shift can lead to significant improvements in energy efficiency, occupant comfort, and building durability far beyond what any one type of insulation can be achieved by a typical stud framed system.



1 view0 comments

Recent Posts

See All

Comments


bottom of page