InterNACHI Roofing Systems and Components 5 — Questions and Answers
Question 1: When inspecting a chimney, a home inspector observes that the mortar crown is cracked and missing sections. What is the primary risk?
- Reduced draft efficiency for the fireplace
- Water infiltration into the chimney structure causing accelerated deterioration (Correct answer)
- Increased risk of chimney fire from creosote buildup
- Loss of structural bond between the chimney and roof flashing
Correct answer: Water infiltration into the chimney structure causing accelerated deterioration
A cracked or missing chimney crown allows water to enter the chimney structure, leading to freeze-thaw damage, efflorescence, and accelerated brick and mortar deterioration.
Question 2: What is the recommended nailing pattern for asphalt shingles to prevent wind uplift?
- 4 nails per shingle placed in the nail zone above the adhesive strip (Correct answer)
- 6 nails per shingle placed randomly across the shingle face
- 2 nails per shingle at each end only
- Nails placed through the tab cutouts for visual alignment
Correct answer: 4 nails per shingle placed in the nail zone above the adhesive strip
Standard practice requires 4 nails per shingle placed in the manufacturer's designated nail zone just above the adhesive strip for optimal wind resistance.
Question 3: A roof inspector finds that counter flashing at a chimney is embedded in the mortar joints but is not sealed. What is the correct assessment?
- This is a serious defect requiring immediate chimney demolition
- Counter flashing embedded in mortar joints is the correct installation method and does not require additional sealant (Correct answer)
- Counter flashing must always be surface-mounted and sealed with caulk
- The flashing is incorrectly installed and must be face-nailed to the chimney
Correct answer: Counter flashing embedded in mortar joints is the correct installation method and does not require additional sealant
Counter flashing correctly embedded (tuck-pointed) into chimney mortar joints provides a secure, water-resistant seal without relying on caulk alone.
Question 4: Which roofing defect is described as a separation of the laminate layers in an architectural (dimensional) shingle?
- Alligatoring
- Delamination (Correct answer)
- Checking
- Granule bridging
Correct answer: Delamination
Delamination in architectural shingles refers to the separation of the top and bottom laminated layers, which compromises the shingle's integrity and weather resistance.
Question 5: What condition should a home inspector report when observing exposed nail heads on the surface of asphalt shingles?
- An acceptable installation technique for steep slopes
- A deficiency requiring repair as exposed nails are a potential leak source (Correct answer)
- Normal appearance of architectural shingles viewed at certain angles
- Evidence of a secondary layer of roofing applied over the first
Correct 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.
Question 6: An inspector observes a roof with two layers of asphalt shingles and significant wear on the top layer. What is the correct finding?
- A third layer may be added per local code before a full tear-off is required
- The roof has reached the maximum allowable layers in most jurisdictions and requires a full tear-off before re-roofing (Correct answer)
- Both layers must be counted together to determine remaining service life
- Two-layer roofs are prohibited and the lower layer must be immediately removed
Correct 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.
Question 7: What is the primary purpose of ice and water shield underlayment installed at roof eaves?
- To increase the fire resistance rating of the roof assembly
- To prevent water infiltration caused by ice dams backing up under shingles (Correct answer)
- To provide a slip-resistant surface for roofing installers
- To add an additional layer of thermal insulation at the cold eave edge
Correct answer: To prevent water infiltration caused by ice dams backing up under shingles
Ice and water shield is a self-adhering, waterproof membrane installed at eaves to prevent water from ice dams from wicking back under shingles and into the structure.
InterNACHI Roofing Systems and Components 5
When inspecting a chimney, a home inspector observes that the mortar crown is cracked and missing sections.
What is the primary risk?