Crawlspace Retrofits in Electrification Projects: Air Sealing and Insulating
April
30,
2026
Part 1 of 2
Crawlspaces come in all shapes and sizes including shallow or hillside, and crawlspaces adjacent to conditioned spaces. The geometry of a crawlspace is an important factor when deciding where to establish a continuous air barrier. Ultimately the insulation will follow and remain aligned with that air barrier. In this course, Dan Perunko of Balance Point Home Performance will present air sealing and insulating strategies for various crawlspace types, along with the myriad benefits effective crawlspace solutions provide for the occupants and the home.
Agenda:
- Introduction and safety message
- Understanding the geometry of the crawlspace
- Using test tools identifying leakage and understanding their limitations
- Air barrier alignment for vented and unvented crawlspaces
- Implications for equipment make-up air in unvented crawlspaces
- Creating continuity in the crawlspace
- Strategies for air sealing leaks in the subfloor
- Air sealing around plumbing fixtures that may require future maintenance
- Removing abandoned or soon-to-be abandoned mechanical equipment that interfaces with the subfloor air barrier
- Air sealing electrical systems and conduits that pass through the subfloor
- Addressing air leakage at masonry fireplaces that pass though the subfloor
The objective of this course is that at the conclusion, participants will be able to:
- Cite areas where the crawlspace air barrier typically lacks continuity
- Identify tests to assess the continuity of the air barrier
- List examples of crawlspace subfloor penetrations that require an air sealing method that can be undone if maintenance is needed
- Name alternatives to batt insulation in the subfloor
- Explain key benefits to air isolating a vented crawlspace from the conditioned spaces
- Summarize post-retrofit testing strategies for continuity and thermal performance
