Applied Roof Systems Practice Exam

FDNY G41 — Use of Liquefied Petroleum Gas or Compressed Natural Gas For Torch- Applied Roof Systems Practice Exam Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• What is the primary fuel used for torch-applied roof systems?
• Nitrogen
• Propane (LPG)
• Helium
• Gasoline

Propane is the approved and most common fuel used for roofing torches due to portability and controlled flame capabilities.

• Which document is required on-site when operating propane torches

on roofs? 1 / 3

• Building blueprint
• Insurance binder
• G41 Certificate of Fitness
• FDNY smoke permit

The G41 Certificate of Fitness must be held by the operator or supervisor to legally perform torch roofing operations.

• What is the maximum allowed propane cylinder capacity used on

roofs for torch-applied roofing?

• 100 lbs per cylinder
• 50 lbs per cylinder
• 20 lbs per cylinder
• Unlimited if secured

FDNY regulations restrict rooftop LPG cylinder size to 20 pounds to minimize fire and explosion hazards.

• When storing propane cylinders on the roof during work breaks, they

must be:

• Laid horizontally
• Stored upright and secured
• Buried under insulation
• Near heat sources

Upright secured cylinders prevent liquid leakage and provide safe vapor pressure control. 2 / 3

• What type of extinguisher must be present during torch-applied

roofing?

• CO₂ only
• Water mist
• 2A-10BC dry chemical extinguisher
• Halon system

A 2A–10BC extinguisher is required because it is effective for flammable gases, liquids, and ordinary combustibles.

6. Before lighting a torch, the operator must check:

• Wind direction
• Roof slope
• All gas connections for leaks
• Weather forecast

Leak-checking prevents ignition of escaping propane which could cause explosions or flash fires.

• Which method is acceptable for checking gas leaks?
• Holding torch flame near the line
• Tapping tank with hammer
• Using soapy water solution
• Shaking the cylinder

Soapy water reveals leaks safely by bubbling rather than risking ignition.

• / 3