NCCER Core Construction Skills 3 — Questions and Answers
Question 1: What is the minimum overlap required when lapping roofing felt (tar paper) on a residential roof?
- 1 inch
- 2 inches
- 4 inches (Correct answer)
- 6 inches
Correct answer: 4 inches
Roofing felt should overlap a minimum of 4 inches at horizontal seams to prevent water infiltration beneath the shingles.
Question 2: Which tool is used to measure and transfer a consistent distance parallel to an edge when laying out cabinet installation lines?
- Combination square
- Marking gauge (Correct answer)
- T-bevel
- Framing square
Correct answer: Marking gauge
A marking gauge has an adjustable fence that rides along an edge to scribe a consistent line at a set distance.
Question 3: A homeowner reports a GFI outlet that won't reset. What is the most likely cause?
- The outlet is wired with reversed polarity
- A downstream fault or overload is still present (Correct answer)
- The circuit breaker needs to be replaced
- The outlet needs a new cover plate
Correct answer: A downstream fault or overload is still present
A GFCI outlet will not reset if a ground fault or wiring issue still exists on the protected circuit downstream.
Question 4: When installing ceramic floor tile, what is the purpose of back-buttering?
- Applying adhesive to both the floor and the tile back for better bond (Correct answer)
- Applying grout to the tile before placing it
- Sealing the tile to prevent moisture absorption
- Leveling uneven tiles after installation
Correct answer: Applying adhesive to both the floor and the tile back for better bond
Back-buttering applies thin-set mortar to the back of the tile in addition to the floor, ensuring full contact and preventing hollow spots.
Question 5: What does 'on center' (OC) mean in framing specifications such as '16" OC'?
- The distance from the outside edge of one stud to the outside edge of the next
- The distance measured from the center of one stud to the center of the next (Correct answer)
- The distance between the inside faces of adjacent studs
- The total width of two studs combined
Correct answer: The distance measured from the center of one stud to the center of the next
On center (OC) spacing is measured from the center of one framing member to the center of the next adjacent member.
Question 6: Which type of caulk is best suited for sealing around a bathtub where it meets the tile surround?
- Acrylic latex caulk
- Silicone caulk (Correct answer)
- Polyurethane caulk
- Butyl rubber caulk
Correct answer: Silicone caulk
Silicone caulk is waterproof, flexible, and mold-resistant, making it the standard choice for wet areas like tub-tile joints.
Question 7: What is the correct way to dispose of lead-based paint chips discovered during a renovation?
- Sweep them into a regular trash bag
- Vacuum with a household vacuum and dispose normally
- Wet-wipe surfaces, bag debris in heavy plastic, follow local hazardous waste regulations (Correct answer)
- Burn them in an outdoor fire to reduce volume
Correct answer: Wet-wipe surfaces, bag debris in heavy plastic, follow local hazardous waste regulations
Lead paint debris must be wet-wiped to suppress dust, sealed in heavy plastic bags, and disposed of per local hazardous waste regulations.
NCCER Core Construction Skills 3
What is the minimum overlap required when lapping roofing felt (tar paper) on a residential roof?