Here are some useful images and diagrams that can be helpful to use as study tools for the NHIE. As a home inspector, you will continue to reference diagrams such as these throughout your career. (Click on the image to see the full detail.)
Some of the more common designs for attics include: Fink (or Common), King Post, Howe, Gable, Scissor, Dual Pitch, Porch, Attic, Gambrel, and Parallel Chord
Notches in a Joist
This diagram shows where and how a joist can be cut, how much can be cut, and areas that should not be cut.
Some additional items to note that are not mentioned in this diagram: "Trimmers" are often referred to as "Jack Studs", "Bottom Plates" are often referred to as "Sole Plates", studs are typically set at 16" on center (OC) with exceptions at openings (doors, windows, etc.)
Service Drop Clearances
Service lines may be the responsibility of the property owner or they can sometimes be the responsibility of the utility provider. In either case, these minimum clearances should be maintained for safety purposes.
Ohm's law (named after the German physicist Georg Ohm) defines the relationship between Voltage, Current and Resistance. Where I is the current, measured in Amperes (Amps/A). R is the resistance, measured in Ohms (Ω). E is the electrical potential (voltage). And W is power, measured in Watts.
E (sometimes V) = Electromotive force or Voltage (measured in volts)
I = Current (measured in Amps)
R = Resistance (measured in Ohms)
E = I X R I = E / R R = E / I
This chart that will help you to better understand the relationship and pattern of sizing for conductors needed for amps / breakers.
Chimneys should extend at least 3' above the highest point that they pass through the roof. They should also extend at least 2' above any part of the roof or building within a 10' radius.
Ridge straps are allowed to be used in lieu of collar ties. However, ridge straps typically can not be observed during the course of a general home inspection.
GFCI Requirements by Year
While home electrical systems are "grandfathered" and are not required to be up to date with code, this is a good chart to help with modern day expectations.
Stucco ID Decision Tree
Stucco siding is not common in our area. This tool will help to identify the types of stucco siding that could be found on homes.
The state of Virginia requires that you "describe in writing" many things including the roof. This is a helpful diagram that shows the most common styles of roof design.
In this illustration, you will see the most common components of a deck. For a complete understanding of decks and how to build them, we recommend that you check our Helpful Links page and follow the link for the Prescriptive Residential Wood Deck Construction Guide.
Here is a diagram that shows the layers and flashing at a headwall (or sometimes referred to as an endwall). While this shows a specific area of a home, the building techniques are similar throughout other locations and components of the home.
This diagram shows some of the basic math allowances for a cantilevered deck.