Identifying Health & Safety and Other Barriers

HEA tends to determine health and safety concerns that can prevent the effectiveness of insulation or air sealing work. The key health and safety barriers are moisture, knob & tube wiring, asbestos-like material, and combustion safety problems. 

1 Moisture 

To insulate a home, it is significant to find the insulation will not become wet and that the insulation will not worsen any current moisture problems. Moisture may be a barrier for some or all measures in the home, based on the severity. Here are certain points for deciding when there is excessive moisture for insulation or air sealing to happen. 


All basements may have a higher level of moisture than the living space since concrete absorbs moisture from the ground. Excessive moisture levels in the basement shall hinder the installation of insulation in the basement. Signs of higher moisture include staining, mold growth, and dirt floors. If the moisture level in the basement is particularly high, then no insulation or air sealing should happen in the home. 


Attic moisture problems are typically caused by one of three things 

1) roof leaks

2) ice damming

3) condensation. 

Roof leaks – Any unrepaired roof leaks are a block for any insulation work in the attic, including cellulose and fiberglass. 

Ice damming – Ice damming is usually caused by excessive heat leaving the home into the attic and melting the snow on the roof that refreezes once the temperature drops. This water seeps into the attic. Air sealing, insulating, and venting the attic can help avoid ice damming as well as moisture intrusion. 

Condensation – Condensation is generally caused by warm, moist air leaving the home and condensing on the cold roof deck. Liquid water accumulates the underside of the roof decking and in severe cases, the water freezes the underside of the roof decking and makes icicles. Air sealing and venting of bath fans decrease the condensation and decrease the chances of moisture intrusion. Air sealing work is completed before installing insulation.

2 Knob & tube wiring 

Knob & tube wiring is usually encountered in pre-1950 houses. Energy Specialists must look carefully via the attic and basement and search for rotary, two-button, or porcelain switches. If any indication of knob & tube wiring is there at the home, no insulation is installed until the homeowner repairs the wiring. Knob & tube wiring is a barrier to insulation in the home except for sites of the home where fully noticeable, uninsulated open cavities let the Energy Specialist visually confirm that no knob & tube wiring is there.

3 Asbestos Like Material

If the Energy Specialist sees any asbestos-like material on the pipes or ducts within the basement or attic, it is a huge barrier as it leads to material disruption. The Energy Specialist should check where pipes go into floors or walls as asbestos-like material is usually missed in such areas. Embossed or smooth paper on ducts could be asbestos-like material. Basement air sealing and basement ceiling insulation might not proceed if there is a threat of disturbing asbestos-like material on pipes in the basement. 

4 Combustion Safety

 Follow all applicable BPI guidelines for checking combustion safety in the home. Any combustion safety problem that is identified as a “stop work” or “emergency” situation per BPI standards is a barrier to any tightening measures on the home, including air sealing and insulation. Unvented fossil fuel space heaters will always stop work until they are removed or vented properly. 

5 Other Health, Safety, or Other Barriers 

  • Access to the house – Rarely a home is too far from the road or the walls are unreachable because of trees or shrubbery. Work that needs access to areas that are jammed by shrubbery or trees might not be possible.
  • Houses that test below BPI 70% of the Building Airflow Standard must have 19 mechanical ventilation installed to proceed with any shell tighten measures. 
  • Structural problems
  • Inability for venting
  • Absence of Carbon Monoxide Detector 
  • Unvented Bath Fan, Dryer, and/or Kitchen Exhaust Fan
  • Minimum Workspace Clearance
  • Floored Attics
  • Heavy Storage Use and Accessibility
  • Overall Safety and Condition of the Home
  • Personal Safety

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