REPORTING- LESSON 3: SECTION 2 – Common Indicators of Potential Failure


One of the main objectives of a home inspection is to determine whether or not a component or system is performing its intended function. In some instances, it is obvious that a system or component is not functioning as intended by virtue of the fact that it will not activate and or operate during the time of the inspection. However, often there are times when observable conditions are indicative that a system or component is not operating as intended and could be defective or potentially going to fail. Since a home inspection is a snapshot in time, signs of potential failure can exist if even when the item inspected either 1) operates but is performing poorly, or 2) is operating as intended at the time of the inspection but could have failed previously or could fail in the near future. This information can be extremely valuable to the client in determining necessary repairs or budgeting for future replacement costs, all of which may negatively affect the equity of their investment in the real property.

There are several common indicators of potential failure when assessing the functionality of components and systems during an inspection. The following observable and audible conditions could be indicative of potential failure.

Structural Cracks or Bowing

There are a variety of stress indicators that could signify whether or not a structural component is functioning soundly. Cracks can be related to various forms of moment and are key indicators of potential failure. It should be noted that stress cracks related to settlement and seasonal movement are not necessarily indicative of structural failure. These cracks are typically straight-lined or vertical in nature. Diagonal and horizontal cracks could be indicative of structural movement, especially displaced cracks

Indicators of potential structural failure are commonly found in the following systems or building components:

  • Displaced cracks in areas of exposed concrete
  • Cracks or wavy mortar joints in brick or stone facades
  • Bowing at interior and/or exterior walls
  • Sagging headers, particularly at garage doors
  • Separations at fascia, soffit, ridge boards joints and unions
  • Excessive gaps at siding materials
  • Fracture or broken sheetrock

Rotten or Decayed Material

Building materials such as wood and composite wood are susceptible moisture damage and therefore could lead to failure due to rot or decay. These conditions could be indicative that caulking, flashing, auto-boots, or pipe fitting have failed.

Indicators of potential failure due to rot and decay may be found in the following building systems and components:

  • Door and window casings
  • Ceiling and floor beam and joists, particularly in basement and crawlspaces
  • Ridge and rafter boards at points of water intrusion 
  • Deck and balcony framing
  • Interior sheetrock and baseboard, particularly around sinks and shower/tub enclosures

Rust & Corrosion – Rust and corrosion are possible indicators that a system or component has failed previously. The rust and corrosion could be masking an active leak at the time of the inspection, but should not be overlooked by the inspector as signs that a system or component has previously failed or may fail in the near future due to deteriorated materials cause by rust and corrosion.

Potential failure related to rust and corrosion are commonly found at the following building components and systems:

  • Plumbing fixtures
  • P-traps and drain components under cabinets
  • HVAC components such as the air handling cabinet and condenser housing, evaporator and condenser coils, and condensate drain systems (emergency pans, exterior termination points)
  • Metal window and door frames, including thresholds
  • Exterior mounted electrical service and/or remote panels

Active Leaks or Water Staining

Obviously, active leaks observed at the time of the inspection could be an indication that a system or component is not operating as intended. However, there times during an inspection that operating a system in normal modes of operation does not result in the observation of an active leak. In these instances, water staining could be indicative of potential failure when the system or component is running under conditions other than those at the time of the inspection.

Signs of active and inactive leaks are commonly found at the following building components or systems:

  • Roof decking, particularly near penetrations involving flashing or boots
  • Attic decking near mechanical units such as HVAC and water heater systems
  • Ceiling or floor staining near roof penetrations or plumbing systems
  • Evidence of collected dust or dirt from pooling water at roof or ground surface grades

Excessive or Unusual Noise/Vibration

Excessive or unusual noise and vibration can be an indication of component failure. These audible and observable conditions can be indicative of failing motor bearings and out of balance rotating components. Excessive noise and or vibration should be noted by the inspector as a possible indicator of system or component failure, even if the system appears to be completing its intended function as the time of the inspection.

Components or systems where these conditions could be present include the following:

  • Condensing unit compressor motors and fan blades
  • Whole house fan motors and blades
  • Mechanical exhaust motors and fan blades
  • Appliance motors and fan blades
  • Overhead garage door openers
  • Circulation pumps

Mechanical Damage

Building system and components can fail due to mechanical damage. Dents, cracks, creases in building materials can lead poor performance or potential failure in the near future. It is wise for home inspectors to make notes of signs of mechanical damage by virtue of the fact the performance or capacity of the system or component could be negatively affected by the damage, whether or not it appear to be operating as intended at the time of the inspection.

Components or systems that could be fail due to mechanical damage include the following:

  • Condenser and evaporator coil fins
  • Garage stored water heaters due
  • Electrical and plumbing fixtures, including switches and handles
  • Roof coverings and flashings
  • Gutters and other surface drainage systems
  • Garage door components and casings

Aged Components

Various types of building systems and components can fail over time simply due to age. Signs that can be indicative of an aged system or component are color fading at housing materials, reduced operation, or an affixed manufactured date.

Typical systems and component that can potentially fail due to age include:

  • Yellowed smoke and carbon monoxide detectors
  • Cracked and or brittle electrical breakers
  • Mechanical system data plates

Lack of Routine Maintenance

Every house is in need or regular maintenance to keep systems running efficiently and ensure appropriate life expectancy. Deferred maintenance on the part of homeowners can lead to potential failure of certain items. Failure to maintain a system regularly can add undue stress to a component operation and shorten its useful life consequently. Notating the conditions indicative of deferred maintenance for your clients is important for both their decision making regarding potentially failing items as well as their education as the nature of maintenance once they take possession of the home.

Lack of regular maintenance and upkeep of the following building materials

  • Excessively dirty air filters for HVAC, venting, and other exhaust systems
  • Lint at dryer ducting and vent termination covers
  • Deteriorating caulk at doors, window, and trim joints
  • Weathered paint or stain at siding, doors, overhang support posts, and decks