Inspection Training

How to Inspect Vent Ducts in the Attic (UPDATED 12/1/17)

While the inspector is in the attic the vent ducting should be examined for proper installation and clearance. It is important to make sure that the vents are venting out of the attic and not venting into the attic. Please review the entire procedure below.



International Standards of Practice for Performing a General Home Inspection


3.9. Attic, Insulation & Ventilation


I. The inspector shall inspect:

B. Ventilation of unfinished spaces, including attics, crawlspaces and foundation areas.

C. Mechanical exhaust systems in the kitchen, bathrooms and laundry area.


II. The inspector shall describe:



III. The inspector shall report as in need of correction:



IV. The inspector is not required to:

A. Enter the attic or any unfinished spaces that are not readily accessible, or where entry could cause damage or, in the inspector’s opinion, pose a safety hazard.
D. Break or otherwise damage the surface finish or weather seal on or around access panels or covers.

Axium SOP Differences

Axium Requires: The inspector should check to make sure that all visible vent ducts aren’t damaged, are properly connected, and are venting through the roof.


Tools Needed

The inspector may require a flashlight to inspect the vent ducts.



  • While the inspector is viewing the attic (while walking or from the entrance) they shall look for all vent ducts to be venting properly to the exterior through the roof. There are two pictures required for this section that show the vents are in good condition and are venting properly through the roof.

Common Defects

  • Gas appliance flue pipe vent not having proper clearance from combustibles.
  • Vent ducts that terminate into the attic and not to the exterior of the property.
  • Vent ducts that are damaged or disconnected.

Common Mistakes

  • Not checking all of the vent ducts in the attic.

Report / Software


  • All vent ducts terminated to the exterior of the property and were properly installed and supported.


  • There was not adequate access to the attic to properly evaluate the vent ducts.


  • There did not appear to be any visible vent ducts in the attic.


  • Defect: [word 1] vent duct terminated in the attic and did not vent to the exterior of the property. A qualified contractor should evaluate and repair as necessary.
    • A bathroom exhaust fan
    • A gas appliance flue pipe
    • A Plumbing
    • An unidentified
    • The dryer exhaust
    • The kitchen range hood
  • Improper Clearance: A gas appliance flue pipe had improper clearance from combustible materials. This type of vent requires a minimum clearance of one inch. This condition is a potential fire hazard. A qualified contractor should evaluate and repair or replace as necessary and according to current standards.