Insulation & Ventilation — NHIE Practice Questions

78 questions in this content area. 4 are published in full below with worked explanations.

1. A crawl space with no ventilation openings and no vapor barrier over the soil is:

AOnly a concern if the crawl space is heated
BAcceptable in every climate zone exactly as it was originally built
A moisture problem — one of the two must be provided
DPreferable to a vented crawl in all situations

Why C is correct

Why this is correct: A crawl space must manage ground moisture. The two primary approved methods are: 1) Ventilation to the outside to dilute and remove moisture, or 2) Sealing and conditioning, which includes covering the soil with a vapor barrier. Having neither allows soil moisture to evaporate and condense on cooler framing, leading to rot and mold. Why the other choices are wrong: "Only a concern if the crawl space is heated" is wrong; moisture is a concern regardless of heating. "Acceptable in every climate zone exactly as it was originally built" is wrong; modern standards recognize this as a problem. "Preferable to a vented crawl in all situations" is wrong; sealed crawls are an alternative, but one method must be used. Exam tip: A crawl space needs either ventilation or a sealed/conditioned approach with a ground cover. Neither is a defect.

2. Attic ventilation that is all exhaust and no intake will:

Draw air from the house through ceiling leaks
BVentilate the attic more efficiently than a balanced system
CHave no effect on the attic's air exchange
DReverse the direction of the ridge vent's flow

Why A is correct

Why this is correct: Balanced attic ventilation requires both intake (typically at the eaves) and exhaust (typically at the ridge). If the system is all exhaust with no dedicated intake, the exhaust fan or vent must draw replacement air from somewhere. The path of least resistance is often through leaks in the ceiling from the conditioned living space below. Why the other choices are wrong: "Ventilate the attic more efficiently than a balanced system" is wrong because an unbalanced system is inefficient and can pull conditioned air from the house. "Have no effect on the attic's air exchange" is wrong because it will cause air exchange, but from the wrong source. "Reverse the direction of the ridge vent's flow" is wrong; the ridge vent's flow direction is determined by pressure and temperature, not solely by the intake/exhaust balance. Exam tip: Remember the principle: ventilation needs a complete path. No intake means the system will pull air from unintended interior sources.

3. In a balloon-framed house, why do the wall cavities matter to the attic?

AThey carry the knob-and-tube wiring upward
BThey make the exterior walls too thin to insulate properly
Open from basement to attic, they act as chimneys for air and fire
DThey conceal the diagonal bracing from inspection

Why C is correct

Why this is correct: The governing concept is that balloon framing creates continuous, open wall cavities from the basement sill to the attic. These act as unintended air passages (chimneys) that can convey air, moisture, and fire rapidly vertically through the structure. Why the other choices are wrong: 'They carry the knob-and-tube wiring upward' is wrong; while wiring may run in walls, this is not the defining characteristic or primary concern of balloon framing. 'They make the exterior walls too thin to insulate properly' is wrong; wall thickness is not inherently different. 'They conceal the diagonal bracing from inspection' is wrong; bracing is not typically concealed in a unique way by balloon framing. Exam tip: Balloon framing = open chutes from bottom to top. Think 'fire and air draft pathways' that need blocking (fire-stopping).

4. Why does an inspector note an attic hatch with no insulation or weatherstripping?

AThe hatch will warp from the temperature difference
BThe hatch cannot be opened for inspection
It is an uninsulated opening in the ceiling plane
DThe hatch must be sized to the attic's floor area

Why C is correct

Why this is correct: The thermal envelope (ceiling plane) must be continuous to prevent heat loss and air leakage. An uninsulated, unsealed hatch is a significant breach in this envelope, akin to a large hole in the insulation. Why the other choices are wrong: 'The hatch will warp from the temperature difference' is possible but not the primary inspection concern; functionality and energy efficiency are key. 'The hatch cannot be opened for inspection' is a practical issue but does not address the defect's impact on the home. 'The hatch must be sized to the attic's floor area' is not a standard requirement; size relates to access, not area. Exam tip: View the attic hatch as part of the ceiling's thermal and air barrier—it should be insulated and weatherstripped like an exterior door.

74 more Insulation questions

Answers and explanations for these are in the study app.

A bathroom exhaust duct runs uninsulated through a cold attic. The predictable result is:
A bathroom exhaust fan discharges into the soffit directly below the roof edge. The concern is:
A bathroom exhaust fan's duct that runs uninsulated through a cold attic will:
A bathroom fan that is quiet and appears to run but does not hold a tissue against the grille:
A bathroom has neither an exhaust fan nor an operable window. Why is this reported?
A bedroom floor over a garage is notoriously cold. What is the usual construction reason?
A crawl space has had its vents sealed and a heavy liner installed over the soil. How should an inspector treat it?
A crawl space that has been sealed and conditioned rather than vented should be evaluated by:
A dryer vent terminating close to a window or air intake may:
A kitchen exhaust duct runs uninsulated through a cold attic. What concern does this raise?
A knee wall in a finished attic with insulation but no air barrier on its back side will:
A kneewall attic access door is bare plywood with no seal or insulation. Why does it matter?
A kneewall separates a finished attic room from the space behind it. What does an inspector look for?
A range hood that recirculates rather than venting outdoors:
A roof-cap exhaust termination is missing its damper flap. Besides heat loss, what commonly follows?
A roof has spray foam directly against the underside of its deck and no vents at all. How should this be read?
A wall assembly has a vapour retarder on both faces. Why is this a concern?
A whole-house fan installed in a ceiling creates what winter concern?
After a light frost, dark parallel streaks appear on a roof while neighbouring roofs stay white. What is being revealed?
Air sealing a ceiling before adding insulation matters because:
Air sealing before adding attic insulation matters because:
An attic contains loose, pebble-like silvery-grey insulation in an older house. How should it be treated?
An exhaust fan in a bathroom moves so little air that tissue will not hold against the grille. The report should:
An exhaust fan terminates a few inches from a soffit vent. Why is this reported?
An exhaust fan's exterior damper is stuck open. What is the winter consequence?
Attic access hatches should be weatherstripped and insulated because:
Attic insulation is deep in some areas and thin in others. What does an inspector report?
Balanced attic ventilation means:
Batt insulation in a wall cavity has been compressed to fit around wiring and pipes. The effect is:
Beyond short-circuiting the soffits, what can a powered attic fan do in a leaky house?
Combining a ridge vent with gable-end vents on the same attic can:
Dark staining appears on the attic sheathing of the north-facing slope only. What does this suggest?
Exposed foam plastic insulation in a basement without a covering is a concern because:
Faced batts in an attic have been installed with the paper facing upward. Why is this reported?
Frost is found coating the nail tips protruding through attic sheathing. What does it indicate?
Gable vents on a house that also has a properly functioning ridge and soffit system should be:
How does air sealing differ from insulating?
Insulation installed against recessed light fixtures that are not IC-rated creates:
Insulation installed between floor joists over an unconditioned basement should:
Insulation stuffed tightly into a cavity rather than fluffed to its rated thickness:
Insulation that has been soaked and dried again is found in an attic. What is its status?
Insulation with a kraft paper facing installed with the paper toward the attic in a cold climate is:
Kraft-faced batts installed with the paper facing the attic side of a ceiling are:
On which side of an insulated assembly does a vapour retarder normally belong?
Recessed light fixtures penetrating an insulated ceiling should be:
Ridge vent installed without cutting the sheathing slot beneath it:
Rigid foam insulation left exposed in a finished basement is a concern because:
Soffit vents are present but have been painted over solid many times. What is their effective condition?
The foil transition hose behind a dryer is crushed nearly flat against the wall. What is the finding?
Tunnels and displaced patches run through attic insulation. Beyond the insulation itself, what does this raise?
What are the cardboard rulers stapled to attic framing for?
What do baffles accomplish in a cathedral ceiling?
What does a radiant barrier in an attic actually do?
What does a vapour barrier on a crawl space floor accomplish?
What does an inspector note about a clothes dryer vented through flexible plastic or foil duct?
What does an insulation R-value express?
What happens when batt insulation is compressed into a space thinner than the batt?
What is expected of an attic access opening?
What is the base ratio for attic ventilation?
What is the mechanism of an ice dam?
What is the spinning turbine vent on a roof designed to do?
What is wind-washing at the eaves?
Where does an inspector look for air bypasses into an attic?
Why can a large kitchen hood need dedicated makeup air?
Why does a very long dryer duct run matter even when the duct is smooth metal?
Why does an inspector consider intake and exhaust ventilation together?
Why does an inspector look at the insulation where the attic meets the exterior wall?
Why does an inspector note a screen fitted over a dryer vent termination?
Why does an inspector note gable vents left open on an attic with a ridge vent?
Why does an inspector note insulation heaped over a recessed ceiling light?
Why does an inspector note lint accumulated around a dryer and its duct connection?
Why does the rim joist area deserve attention in a basement inspection?
Why is the dropped soffit above kitchen cabinets a classic energy defect?
Why is ventilation measured in net free area rather than opening size?

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