Mixed Deck — All INTERNACHI Topics Flashcards

What does a home inspector look for when evaluating a gas appliance's combustion air supply?

Answer: Whether adequate air openings exist to support complete combustion

Combustion appliances require sufficient air supply to burn fuel completely; inadequate combustion air leads to carbon monoxide production and flame rollout.

Which type of pipe is most commonly identified by its blue or black color and is acceptable for potable cold-water supply lines?

Answer: PEX

PEX (cross-linked polyethylene) is commonly color-coded blue for cold water and red for hot water, and is approved for potable water supply.

When inspecting a home built on expansive soils (clay), an inspector should be especially alert to which structural pattern?

Answer: Differential heaving or settlement causing doors to stick and diagonal cracks at opening corners

Expansive soils swell when wet and shrink when dry, causing differential movement that leads to sticking doors, diagonal cracks at opening corners, and uneven floors.

What is the primary concern of electrical systems in home inspections?

Answer: Safety and code compliance

The paramount concern when inspecting electrical systems is ensuring the safety of the occupants and compliance with current electrical codes. Inspectors look for hazards like improper wiring, overloaded circuits, lack of grounding, and outdated components that could lead to electrical fires, shocks, or system failures. Aesthetic appeal or consumption rates are secondary to safety.

An inspector finds that a wood beam has a horizontal split running along its length. What type of defect is this?

Answer: Checking or splitting along the grain (seasoning crack)

Horizontal splits running along the grain are called checks or seasoning cracks, caused by wood drying unevenly; while typically cosmetic, deep checks in load-bearing members warrant further evaluation.

Which type of foundation wall crack is most indicative of differential settlement?

Answer: Diagonal stair-step crack in a masonry block wall

Diagonal stair-step cracks in masonry block walls typically indicate differential settlement, where one section of the foundation is moving more than another.

An inspector finds a furnace flue pipe that pitches downward toward the furnace rather than upward toward the chimney. Why is this a defect?

Answer: Condensate and combustion gases will not draft properly and can back-flow into the home

Flue pipes must maintain an upward pitch (minimum 1/4 inch per foot) toward the chimney so that buoyant combustion gases — including carbon monoxide — rise and exit rather than back-drafting.

An inspector observes a roof with two layers of asphalt shingles and significant wear on the top layer. What is the correct finding?

Answer: The roof has reached the maximum allowable layers in most jurisdictions and requires a full tear-off before re-roofing

Most building codes allow a maximum of two layers of asphalt shingles; adding a third layer typically requires a complete tear-off of existing material first.

A home inspector observes that a load-bearing wall has been removed and a header installed. What additional concern should be noted if no posts are visible at the header ends?

Answer: The load may not be transferred properly to the foundation without adequate bearing posts

Header loads must be transferred down to the foundation through bearing posts or columns; missing posts mean the load path is interrupted and the structure may be compromised.

A home inspector notices the bottom course of lap siding is within 2 inches of grade. What is the primary concern?

Answer: Increased risk of wood rot and pest entry

Siding that is too close to grade is exposed to soil moisture and splash-back, accelerating rot and providing a pathway for termites.

What is the term for the condition where floor joists bear on a foundation wall or beam at less than the minimum required distance?

Answer: Insufficient bearing

Insufficient bearing occurs when floor joists rest on a support surface with less than the code-required minimum contact length, typically 1.5 inches on wood and 3 inches on masonry.

In a cathedral ceiling with no attic space, what minimum ventilation channel depth is typically required between the roof deck and insulation?

Answer: 1 inch

Building codes and InterNACHI standards generally require a minimum 1-inch continuous air channel between the top of the insulation and the roof sheathing in cathedral ceiling assemblies.

What is the standard InterNACHI recommendation when a home inspector cannot fully evaluate a component of the HVAC system?

Answer: Report it as inaccessible or unable to be inspected and recommend further evaluation by a qualified HVAC technician

InterNACHI standards require inspectors to report any system or component that could not be inspected and to recommend specialist evaluation when warranted.

Which of the following describes a 'floating neutral' condition at a sub-panel?

Answer: The neutral wire is connected to the ground bus, creating a fault path

At a sub-panel, a floating neutral means the neutral bus is incorrectly bonded to the ground bus, which should only occur at the main panel.

What condition should a home inspector report when observing exposed nail heads on the surface of asphalt shingles?

Answer: A deficiency requiring repair as exposed nails are a potential leak source

Exposed nail heads on shingle surfaces indicate improper nailing above the nail zone and are a reportable deficiency as they create a direct pathway for water infiltration.

An inspector observes an overhead service drop that is attached to a mast on the roof. The conductors pass within 2 feet horizontally of the side of a window that is designed to be opened. What should the inspector report?

Answer: This is a safety hazard, as a minimum clearance of 3 feet is required from the sides of operable windows.

NEC Section 230.9(A) requires overhead service conductors to maintain a clearance of at least 3 feet from the sides, top, and bottom of windows that can be opened. This is a critical safety rule to prevent accidental contact with energized conductors by a person or an object passed through the window. An inspector should report this as a safety hazard.

An inspector is examining the interior of an attached garage and notes that the entry door leading into the house is a standard, hollow-core interior door. Why is this a significant defect?

Answer: The door lacks the required fire-resistance rating to slow the spread of a fire from the garage to the living space.

The door between an attached garage and the living area is part of the fire separation. Building codes require this door to be a solid wood door at least 1-3/8 inches thick, a solid or honeycomb-core steel door of the same thickness, or a door with a minimum 20-minute fire rating. A hollow-core door offers minimal fire resistance and is a serious safety hazard.

Which refrigerant was widely phased out of residential air conditioning systems due to ozone depletion concerns?

Answer: R-22 (Freon)

R-22 (chlorodifluoromethane, marketed as Freon) was phased out under the Clean Air Act because its chlorine atoms deplete stratospheric ozone.

Which roofing material requires the installation of a solid or spaced wood deck for proper performance?

Answer: Wood shingles and shakes

Wood shingles and shakes require either solid or spaced sheathing to allow airflow beneath them for drying and to prevent moisture-related decay.

A home inspector observes that floor joists run parallel to one side of a bathtub but the subfloor feels soft and spongy near the tub. What is the most likely structural cause?

Answer: Water damage from tub or plumbing leaks has caused decay in joists and subfloor

Soft, spongy subfloor near a bathtub most commonly indicates chronic water intrusion from the tub or plumbing has caused wood decay in the subfloor and underlying joists.