21 Roofing, Exterior & Site Practice Questions & Answers

1. 1. A porch roof with a very shallow pitch is covered with lapped asphalt shingles, and the inspector notes staining on the porch ceiling below. Which statement best expresses the principle that relates roof slope to the type of covering that belongs on it?

   • A.Lapped coverings perform best where water lingers, because the extra dwell time helps the laps seal themselves
   • B.Slope has no bearing on covering selection as long as an underlayment has been installed beneath the covering
   • C.A lapped covering only sheds water: it depends on gravity and adequate slope to carry water over each lap before wind or standing water can drive it back underneath, so a shallow roof instead needs a continuous membrane with sealed seams✓ Answer
   • D.Any covering may be used at any slope provided the exposed fasteners are bedded in roofing cement at installation

   Lapped coverings such as shingles, shakes, slate and tile are water-shedding, not waterproof: each course simply overlaps the one below, and gravity must move water across that lap faster than wind pressure or ponding can push it back. When slope is too shallow for that to happen reliably, the assembly must change in kind to a continuous, seamed membrane rather than merely adding more laps.

   Source: National Home Inspector Examination content outline — roof components; residential building science, water-shedding versus waterproof roof assembliesReport a problem with this question

2. 2. On an asphalt-shingle roof an inspector finds soft, roughly round spots of granule loss scattered randomly over all four slopes, some with a bruised, fractured mat that gives slightly under thumb pressure. On a different area, granule scuffing follows a narrow path from the ladder point to a rooftop appliance. What do these two patterns most likely indicate?

   • A.The random, soft, round bruises are characteristic of hail impact, while the scuffing confined to a route between the ladder and the equipment is characteristic of mechanical foot-traffic damage✓ Answer
   • B.Both patterns are ordinary weathering and should be omitted from the report because granule loss is universal
   • C.Both patterns indicate manufacturing defects in the shingles and neither is related to any outside force
   • D.The random bruises are foot traffic and the pathway scuffing is hail, since hail tends to fall in concentrated lines

   Distinguishing look-alike damage is a core inspection skill: hail arrives from the sky and therefore strikes randomly across all exposures, leaving soft, circular bruises where the mat is fractured beneath the granule loss, whereas foot traffic is human and therefore concentrated along access routes and around serviced equipment, producing linear scuffing and sometimes cracked tabs. The inspector reports the observed condition and its pattern rather than certifying a cause for an insurance claim.

   Source: National Home Inspector Examination content outline — roof coverings, typical defects and damage identificationReport a problem with this question

3. 3. A home has a brittle clay tile roof. The inspector determines that walking the surface would crack tiles, and inspects instead from a ladder at the eaves and from the ground with binoculars. Which report language is most appropriate?

   • A.State that the roof was inspected from the eaves and from the ground with binoculars because walking the tile would damage it, describe the conditions observed, and note that this method limits what could be seen✓ Answer
   • B.Walk the roof anyway so the inspection is complete, and note any tiles broken during the inspection
   • C.State that the roof is in satisfactory condition and is not expected to leak during the client's ownership
   • D.Omit the roof entirely from the report, since a roof that cannot be walked cannot be inspected

   A home inspection is visual and non-invasive and must not damage the property, so fragile coverings are properly viewed from the eaves, the ground or another vantage point. The report must state both what was observed and the method and resulting limitation, and it must never promise future leak-free performance or predict remaining service life.

   Source: Home inspection standards of practice — visual, non-invasive scope; reporting the method used and what was not inspected and whyReport a problem with this question

4. 4. On an exposed-fastener metal panel roof, the inspector sees rust rings around many screw heads, several screws standing proud of the panel, and dark streaking on the panels below them. What is the most likely mechanism?

   • A.The sealing washers under the screw heads have hardened and lost compression, and repeated thermal expansion and contraction of the panels has backed the screws out, so each fastener is now an open, leaking penetration✓ Answer
   • B.The streaking is algae growth and has no relationship to the fasteners
   • C.The panels were installed over a membrane, so fastener condition is not a leak concern
   • D.The panels are oil-canning, which by itself causes the screws to loosen and rust

   An exposed-fastener metal roof is watertight only because a resilient washer is held in compression against the panel; ultraviolet exposure and heat harden that washer while daily thermal movement of long metal panels works the screws loose. Rust rings and backed-out screws therefore signal hundreds of active penetrations, and the rust staining below them is the corrosion product washing down the panel.

   Source: National Home Inspector Examination content outline — roof coverings, metal roofing materials and typical defectsReport a problem with this question

5. 5. On a low-slope built-up roof, water is still standing in a broad area three days after the last rain, the surfacing shows a network of fine cracks resembling dried mud, and several laps have lifted blisters. How should the inspector characterize these findings?

   • A.Blisters at the laps prove the roof deck is over-fastened and the framing is overloaded
   • B.Water that fails to drain within a reasonable period indicates a drainage deficiency, the alligatored surfacing indicates an aged and embrittled coating, and the blistered laps are open paths for water; together they call for evaluation by a qualified roofing contractor✓ Answer
   • C.Alligatoring of the surfacing is purely cosmetic and never warrants comment
   • D.Ponding is beneficial because the water ballasts the membrane against wind uplift

   Standing water on a low-slope roof adds sustained load, accelerates degradation of the surfacing and bitumen, and will find any open lap, so a roof that does not drain within a reasonable period after rain is reported as a drainage deficiency. Alligatoring is the surfacing shrinking and cracking as it ages and loses volatiles, and blistered or open laps are the seams that make a membrane continuous beginning to fail.

   Source: National Home Inspector Examination content outline — low-slope membrane roof coverings, ponding and typical defectsReport a problem with this question

6. 6. Where a sloped roof meets a vertical sidewall, the inspector finds one continuous L-shaped metal strip running the full length of the intersection, with its vertical leg caulked to the siding. Why is this a defect?

   • A.The defect is the metal itself, since flashings at roof-to-wall intersections must be made of a flexible membrane
   • B.It is not a defect, because a single continuous piece has fewer joints than many small pieces and is therefore more watertight
   • C.Continuous flashing is only a defect on the north side of a building, where drying is slower
   • D.The intersection should be flashed with individual step flashings, one per shingle course, interwoven with the courses and lapped over by the wall's water-resistive barrier and cladding, so that any water reaching the wall is directed out onto the course below; a continuous strip has no such drainage path and relies on sealant✓ Answer

   Step flashing works because each individual piece is laid with a shingle course and lapped by the piece above, creating a stepped, shingle-fashion drainage path that hands water down and out onto the roof. A continuous strip breaks that layering: water running down the wall behind the cladding has nowhere to escape and the only thing keeping it out is a bead of sealant, which is a maintenance item and fails.

   Source: National Home Inspector Examination content outline — roof flashings, roof-to-wall intersectionsReport a problem with this question

7. 7. A sloped roof intersects a two-story wall and terminates just above a gutter. There is no diverter at the lower end of the roof-to-wall flashing. Inside, the ceiling and wall below show staining, and the siding at that corner is soft. What is the most likely explanation?

   • A.Without a kickout (diverter) flashing at the lower termination, roof runoff concentrated in that valley of the intersection runs past the gutter and behind the cladding, saturating the sheathing and framing concealed within the wall✓ Answer
   • B.The staining is condensation from the interior and unrelated to the roof-to-wall detail
   • C.The gutter is undersized, and enlarging the gutter will resolve the interior staining
   • D.The shingles are the wrong color and are absorbing excess heat, driving moisture into the wall

   The lower end of a roof-to-wall intersection collects the runoff from the whole roof plane above it, and a kickout flashing is the small angled piece that throws that concentrated stream out into the gutter. When it is missing, the water follows the wall face, gets behind the cladding, and rots sheathing and framing invisibly for years, which is why a missing kickout is a classic cause of major concealed damage.

   Source: National Home Inspector Examination content outline — roof flashings, kickout and roof-to-wall terminations; concealed moisture damage in wall assembliesReport a problem with this question

8. 8. At a masonry chimney passing through a sloped roof, the base and step flashing appear sound, but the upper edge of the metal is simply bedded in a bead of sealant against the face of the brick. What is the correct description of this condition?

   • A.Counterflashing is unnecessary on any chimney that has a rain cap
   • B.This is the preferred method, because cutting a reglet into mortar weakens the chimney
   • C.The condition is acceptable if the sealant is the same color as the mortar
   • D.Counterflashing should be let into a mortar joint or reglet in the masonry and lapped down over the base flashing, so that water running down the chimney face is carried out over the flashing; sealant against the brick face is a maintenance item that will fail and is not a substitute✓ Answer

   Chimney flashing is a two-part system: base and step flashing turned up the masonry, and counterflashing let into the masonry above it and lapped down over the base. Letting the counterflashing into a joint puts the top edge behind the masonry so water on the wall cannot get behind the metal, which sealant alone can never accomplish once it shrinks, cracks and loses adhesion.

   Source: National Home Inspector Examination content outline — roof flashings and masonry chimney flashing detailsReport a problem with this question

9. 9. A plumbing vent pipe penetrating an asphalt-shingle roof has a rubber boot collar that is split and cracked around the pipe, and a heavy trowelled layer of roofing cement has been applied over it. A stain is visible on the ceiling below. What is the best inspector response?

   • A.Report the cracked boot and note that the roofing cement is evidence of a previous repair attempt rather than a proper repair, describe the interior stain, and recommend replacement of the boot by a qualified roofing contractor✓ Answer
   • B.Apply additional roofing cement during the inspection to stop the active leak
   • C.Note that the cement has sealed the penetration and no further action is needed
   • D.Report that the vent pipe is undersized and recommend a plumber enlarge it

   Rubber pipe-boot collars are among the most common single-item roof leak sources because ultraviolet exposure hardens and splits the collar long before the shingles wear out, and roofing cement over a failed detail is a temporary patch that cracks with thermal movement. The inspector observes and reports the condition and refers it to the appropriate trade rather than performing repairs, which is outside the scope of an inspection.

   Source: National Home Inspector Examination content outline — roof penetrations and flashings; standards of practice, inspectors observe and report rather than repairReport a problem with this question

10. 10. An inspector finds gutters that hold standing water at the end farthest from the downspout, dark water staining and softened wood on the fascia directly behind the gutter, and downspouts that discharge onto the soil immediately at the foundation wall. Which statement best captures these findings?

    • A.The gutters are back-pitched so water cannot reach the downspout, water is getting behind the gutter at the eave edge and decaying the fascia, and the downspouts are saturating the soil against the foundation; all three should be reported with a recommendation to correct the pitch, the eave edge detail and the discharge location✓ Answer
    • B.These are three unrelated cosmetic items that do not belong in an inspection report
    • C.The fascia decay proves a roof covering failure directly above and the covering should be replaced
    • D.Back-pitched gutters are desirable because they slow the water and reduce erosion at the downspout

    Roof drainage is a chain, and each link failed here: a gutter must fall toward its outlet or it holds water and debris, an edge flashing must carry water from the roof edge into the gutter or surface tension draws it back onto the fascia, and the discharge must be carried away from the building or the collected roof water is simply delivered to the backfill beside the foundation.

    Source: National Home Inspector Examination content outline — roof drainage systems, gutters, downspouts and dischargeReport a problem with this question

11. 11. After a snowfall, a house shows bare, melted roof over the main heated area but intact snow over the eave overhang, a thick ridge of ice at the eave with long icicles, and fresh staining on the top-floor ceiling near the exterior wall. What is the mechanism, and what is the durable correction?

    • A.The shingles are defective and are absorbing solar heat unevenly; replacing the covering will prevent future ice dams
    • B.The gutters caused the melting and removing the gutters entirely will eliminate the problem
    • C.Heat cable installed along the eave is the durable correction because it removes the cause of the dam
    • D.Heat and air leakage from the living space warm the roof deck over the heated area and melt the snow; the meltwater runs down and refreezes over the cold, unheated overhang, and the resulting dam backs water up under the lapped covering. The durable correction is air sealing, added insulation and balanced attic ventilation to keep the deck cold✓ Answer

    Ice damming is a building-science problem, not a roofing-material problem: the tell-tale is snow melted over the heated portion of the roof but intact over the unheated overhang, which proves interior heat is reaching the deck. Because a lapped covering only sheds water, ponded water held behind the dam runs backward under the laps; an eave ice barrier is protection against that, while heat cable only melts a channel through the symptom.

    Source: National Home Inspector Examination content outline — insulation, moisture management and ventilation of attics and roof assemblies; ice dam formationReport a problem with this question

12. 12. The top of a masonry chimney is finished with a thin mortar wash that is cracked and crumbling, the upper courses of brick have faces flaking off, and the mortar joints there are eroded and soft. What best explains this deterioration and the correct detail?

    • A.The flaking is caused by flue gases condensing on the outside of the brick, and relining the flue will stop it
    • B.Spalling is caused by the chimney being too tall, and shortening it is the correct repair
    • C.The flaking is normal patina on any brick over ten years old and requires no comment
    • D.A thin mortar wash cracks and lets water into the top of the chimney; absorbed water then freezes and expands within the brick and joints, flaking the faces and eroding the mortar. The proper detail is a cast, sloped crown that overhangs the chimney face with a drip edge, together with a rain cap✓ Answer

    A chimney crown is a roof for the masonry below it, and a thin mortar wash is too weak and too thin to survive thermal movement, so it cracks and admits water. Once masonry is chronically wet, freeze-thaw cycling breaks the fired face off the brick and washes out the joints, which is why a cast crown that overhangs with a drip edge, plus a rain cap, is the durable detail.

    Source: National Home Inspector Examination content outline — chimney terminations, crowns, caps and masonry deteriorationReport a problem with this question

13. 13. An inspector observes that an exterior masonry chimney has rotated away from the wall of the house, leaving a wedge-shaped gap that is wider at the top, with stair-step cracking in the mortar joints near the base. What is the appropriate action?

    • A.Report it as a cosmetic separation typical of differential settlement and note that no action is needed
    • B.Determine the bearing capacity of the chimney footing and state in the report how much the footing must be underpinned
    • C.Report the observed movement as a significant and potentially unsafe condition, recommend that the chimney not be used until it is evaluated by a qualified structural professional, and note that the cause and extent cannot be determined by a visual inspection✓ Answer
    • D.Seal the gap with exterior sealant during the inspection so water cannot enter

    A chimney rotating away from the house indicates footing failure or structural movement, and a leaning mass of masonry above a roof is a collapse and injury hazard as well as a flue-integrity concern. The inspector's role is to identify the condition, convey the safety implication, and refer it to the qualified professional, not to diagnose the cause, quantify the remedy or perform repairs.

    Source: National Home Inspector Examination content outline — analysis of findings and reporting; recommending evaluation by the appropriate qualified professionalReport a problem with this question

14. 14. While siding was removed for a repair, the inspector can see that at one horizontal seam the upper sheet of water-resistive barrier was tucked behind the lower sheet. Why does this matter, and what principle governs wall assemblies?

    • A.It only matters in wind-driven rain climates, and sealing the seam with tape makes any lap direction acceptable
    • B.It matters only if the barrier is a paper-based product rather than a plastic housewrap
    • C.It does not matter, because the cladding above is intended to be a sealed, watertight barrier and the barrier behind it is only a wind block
    • D.This is a reverse lap: a wall is a drained assembly, and the water-resistive barrier and all flashings must be lapped shingle-fashion so any water that gets past the cladding is always directed outward and downward; a reverse lap funnels that water into the sheathing instead✓ Answer

    Modern wall design assumes some water will get past the cladding, so the cladding is treated as a screen and the water-resistive barrier behind it is the actual drainage plane. Because water moves by gravity, every lap and every flashing must be layered upper-over-lower; one reverse lap turns the drainage plane into a funnel that delivers water directly to the sheathing.

    Source: Residential building science — the drained wall principle, water-resistive barrier and shingle-fashion flashing integrationReport a problem with this question

15. 15. At the base of a brick veneer wall the inspector finds that the small openings in the head joints have been filled with mortar and painted over. Inside, the lower wall shows efflorescence and damp staining. What is the significance?

    • A.Weep openings are decorative and closing them improves the wall's weather resistance
    • B.Brick is impermeable, so any moisture inside must originate from interior humidity alone
    • C.Brick veneer is a drained assembly with an air space, a water-resistive barrier and through-wall flashing at its base; the weep openings are the only exit for water collected on that flashing, so blocking them traps water in the cavity and drives it inward✓ Answer
    • D.The efflorescence proves a plumbing leak inside the wall and the weeps are unrelated

    Brick absorbs and passes water, so a masonry veneer is designed to leak into a drainage cavity where through-wall flashing catches the water and weep openings let it back out. Sealing the weeps removes the exit while the entry remains, so the cavity holds water against the sheathing and dissolved salts appear as efflorescence when that moisture migrates and evaporates.

    Source: National Home Inspector Examination content outline — wall cladding, masonry veneer drainage, through-wall flashing and weep openingsReport a problem with this question

16. 16. A house is clad in an adhered synthetic stucco assembly. The inspector finds cracked and separated sealant at window perimeters and at a deck ledger penetration, with dark streaking below. What is the most appropriate report entry?

    • A.Describe the visible sealant failure and staining, explain that an adhered synthetic stucco assembly of this type depends on sealed joints because it lacks a drainage path, and note that determining whether water has entered requires invasive moisture testing beyond a visual inspection, so evaluation by a qualified specialist is recommended✓ Answer
    • B.Report that the cladding has failed and specify complete removal and replacement of the wall assembly
    • C.Report that synthetic stucco always performs adequately and that sealant cracking is cosmetic
    • D.Probe the wall with a moisture meter through drilled holes during the inspection and report the readings as conclusive

    A face-sealed assembly relies on the perfect-barrier strategy: with no drainage cavity behind it, every joint and penetration must stay sealed, so cracked sealant is a direct pathway rather than a cosmetic issue. Because damage occurs behind an intact-looking surface and confirming it requires probing, the inspector reports the visible condition and the limitation of a visual inspection and refers it out.

    Source: National Home Inspector Examination content outline — wall cladding types and typical defects; standards of practice, limits of a visual non-invasive inspectionReport a problem with this question

17. 17. A double-glazed window shows a hazy film and faint mineral-looking streaks that are visible only in certain light and that do not change when both the inside and outside glass surfaces are wiped clean. What does this indicate?

    • A.The glass is dirty on the interior surface and only needs cleaning by the occupant
    • B.The perimeter seal of the insulated glass unit has failed, allowing moisture into the sealed cavity where it condenses and deposits residue between the panes; it cannot be corrected by cleaning and the unit or sash should be replaced✓ Answer
    • C.The haze is normal for all insulated glass and is not reportable
    • D.The window frame is out of square, which distorts the glass and creates the haze

    An insulated glass unit is a sealed cavity, so the only way moisture appears between the panes is failure of the perimeter seal or its desiccant, and repeated condensation leaves mineral residue etched on the inner surfaces. The defining test is that the haze is between the panes and therefore unaffected by cleaning either exposed face, and visibility varies with temperature, humidity and sun angle.

    Source: National Home Inspector Examination content outline — exterior doors and windows, glazing condition and typical defectsReport a problem with this question

18. 18. An attached deck ledger is fastened to the house rim area with common nails and coated deck screws, and there is no flashing above the ledger. How should the inspector treat this?

    • A.Note it as a minor workmanship item, since the deck is currently standing and shows no movement
    • B.Recommend the client add more of the same deck screws to increase the number of fasteners
    • C.Report that the ledger is acceptable if the deck is less than ten years old
    • D.Report it as a life-safety defect: the ledger connection carries the deck's entire load back into the house and requires fasteners engineered for that withdrawal and shear demand, arranged in a staggered pattern, plus flashing to keep water off the connection; recommend correction by a qualified contractor before the deck is used✓ Answer

    Deck collapses overwhelmingly begin at the ledger, because that single connection transfers the entire deck load, including live load from occupants, into the house. Nails and generic deck screws are loaded in withdrawal and can pull out progressively without warning, and an unflashed ledger stays wet so the wood it bears on decays, which is why this combination is reported as an immediate safety concern rather than a workmanship note.

    Source: National Home Inspector Examination content outline — decks and balconies, ledger attachment, fasteners and flashing; life-safety findingsReport a problem with this question

19. 19. Under a raised deck, the inspector finds the built-up beam nailed to the side face of each support post with angled nails, rather than bearing on top of the post or in a notch. Why is this reported as a defect?

    • A.Toe-nailing puts the fasteners in withdrawal and shear across the grain with no positive bearing, so the beam is hanging on nails rather than resting on the post; the beam should bear on top of the post or in a notch, with a positive metal connector, so the load transfers in direct compression✓ Answer
    • B.Side-nailed beams are stronger because the post can then be a smaller dimension
    • C.The connection is acceptable as long as the posts are pressure-treated
    • D.It is not a defect, because angled nails hold better than any other fastening method

    Sound wood framing transfers vertical load through direct bearing, wood in compression, with metal connectors added to resist uplift and lateral displacement. Toe-nails were never intended to carry gravity load, so a side-nailed beam depends on a few nails in withdrawal that loosen with seasonal movement and vibration, and this is one of the most common findings behind deck failures.

    Source: National Home Inspector Examination content outline — decks and balconies, post-to-beam connections and load pathReport a problem with this question

20. 20. A basement wall shows a white powdery deposit and damp staining along its base. Outside, the soil slopes back toward the house, mulch is piled above the bottom edge of the siding, and a downspout discharges at the wall. Which answer traces the complete path by which surface water reaches the basement?

    • A.Basement dampness is always caused by a high water table and site work cannot influence it
    • B.Roof water is delivered by the downspout to the soil at the wall, negative grade holds that water against the foundation instead of carrying it away, the loose backfill stays saturated, and water then moves through the wall by pressure and capillary action, leaving dissolved salts as efflorescence as it evaporates inside✓ Answer
    • C.The mulch above the siding is the sole cause and removing it will dry the basement
    • D.The efflorescence is mold growth caused by interior humidity alone and has no exterior source

    Most basement water problems are surface-water problems, and the fix is at the top of the chain rather than inside: get roof water discharged well away from the building and slope the ground so it falls away from the foundation for a reasonable distance. Efflorescence is not the leak itself but its signature, the mineral salts left behind after water passed through the masonry and evaporated, and mulch above the siding line adds a wicking, decay-prone earth-to-cladding contact.

    Source: National Home Inspector Examination content outline — site conditions, grade and surface drainage; residential building science, surface water and foundation wettingReport a problem with this question

21. 21. A segmental block retaining wall behind a house bulges outward at mid-height, the top course leans forward, no weep openings are visible at the base, and the soil behind the wall is saturated with a downspout discharging above it. What is the most likely mechanism and the correct inspector response?

    • A.Bulging in a retaining wall is normal seasonal movement and reverses each summer
    • B.Water trapped behind the wall builds hydrostatic pressure that pushes the wall outward and rotates it forward; drainage aggregate, filter fabric and open weep or drain outlets are what relieve that pressure. The inspector reports the movement and the absent drainage, notes the collapse hazard, and recommends evaluation by a qualified engineer or contractor✓ Answer
    • C.The blocks were manufactured undersized, and repointing the joints will restore the wall
    • D.The wall is fine because segmental block walls are designed to lean forward for appearance

    A retaining wall resists the lateral push of soil, and saturated soil pushes far harder than drained soil because water adds hydrostatic pressure to the earth pressure. Bulging, leaning, rotation and displaced courses are the visible evidence that the pressure exceeds what the wall was built to resist, and since the internal construction and any tie-backs cannot be seen, the inspector describes the condition and the hazard and refers it rather than diagnosing the design.

    Source: National Home Inspector Examination content outline — site conditions, retaining walls, drainage and typical failure modesReport a problem with this question

Practice questions based on the National Home Inspector Examination content outline, widely shared home inspection standards of practice, and residential building science. Not affiliated with or endorsed by any examination board, licensing authority, or inspector association. A home inspection is a visual, non-invasive examination and is not a code-compliance inspection — nothing here should be read as a code requirement. Home inspection is regulated differently from place to place; confirm your own jurisdiction's requirements and the standards of practice you are held to before testing or inspecting. About the National Home Inspector Examination →