Inspection Training

How to Inspect for Basement Moisture Intrusion

While the inspector is in the basement they should inspect for any signs of moisture intrusion. One way to do this is to use the moisture meter and place it on all of the walls. Please review the entire procedure below.



International Standards of Practice for Performing a General Home Inspection


3.3. Basement, Foundation, Crawlspace & Structure


I. The inspector shall inspect:

A. The foundation.

B. The basement.


II. The inspector shall describe:
A. The type of foundation.


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

A. Observed indications of wood in contact with or near soil. B. Observed indications of active water penetration.


IV. The inspector is not required to:

B. Move stored items or debris.


Axium SOP Differences

Axium Requires: Same as NACHI Standards of Practice.


Tools Needed

The inspector will use the moisture meter to check all of the walls in the basement for any signs of moisture intrusion.



  • While inspecting the basement we will want to check for any signs of moisture intrusion by checking all of the accessible walls with the moisture meter. Make sure the moisture meter is on the correct setting for what you are testing (i.e., walls, concrete, etc.). We want to make sure that we test all areas of the walls for the moisture intrusion.
  • If there are no signs of moisture intrusion, we will take two pictures for this section that will show that no moisture was present at the time of the inspection. Both pictures should show the moisture meter on the wall and clearly show the moisture percentage on the meter. If you find moisture intrusion, efflorescence, or mold make sure to take a lot of pictures to document the defects.


Common Defects

  • There is efflorescence present in the basement.
  • There is mold present in the basement.
  • There are signs of moisture intrusion present in the basement.

Common Mistakes

  • Not checking all of the locations, including the foundation walls, for signs of moisture intrusion that can lead to the development of mold and efflorescence.
  • Not using your moisture meter on multiple areas of the foundation walls (even if finished) to test for signs of moisture behind the walls.
  • Not taking pictures with the moisture meter in the picture that clearly shows the percentage of moisture on the meter.

Report / Software


  • There were no visible signs of water intrusion or moisture in the basement at the time of the inspection.


  • N/A


  • There were no visible signs of water intrusion or moisture in the basement at the time of the inspection.


  • Efflorescence: White efflorescence (powder substance) on concrete wall indicates moisture is in contact with the foundation. This does not necessarily indicate that intrusion will occur. I recommend checking the gutters and down spout drain lines for proper operation. Also, a water proofing paint could be applied to the interior side of the foundation if necessary. Efflorescence is found on many properties without water intrusion occurring inside the property. But, it should alert you to the possibility that future steps may be needed. A qualified contractor should evaluate and make necessary repairs according to current standards.
  • Mold: Evidence of possible mold-like substance growth was observed [word 1]. We did not inspect, test or determine if this growth is or is not a health hazard. The underlying cause is moisture. I recommend you contact a mold inspector or expert for investigation or correction if needed.
    • Location
      • Basement (Floor Overhead)
      • Basement (Wood Floor)
      • Bathroom Cabinets
      • Caulking/Grout
      • Crawlspace (Floor Overhead)
      • Kitchen Cabinets
      • Walls (Basement
      • Walls (Bathroom Around Bathtub)
      • Walls (Garage)
      • Walls (Laundry)
      • Walls (Water Heater)
  • Moisture Intrusion: The visible areas of the basement foundation walls show signs of possible previous moisture intrusion and/or deterioration. A qualified contractor should evaluate and repair or replace as necessary and according to current standards.