CSLB C-39 Roofing Contractor flashcards

Cal/OSHA requires a fire watch to remain on site for a minimum of 30 minutes after hot work operations are completed.

• Prevents delayed ignition.
• Applies to all hot work (torch, welding, etc.).
• Fire watch must be properly equipped.

Memory trick: Thirty minutes, watch the fire's last gleam, then you can leave, like a fading dream.

Roof insulation that has absorbed water, compromising its thermal performance and potentially leading to structural and mold issues.

• Reduces R-value significantly.
• Can lead to mold and rot.
• Must be removed and replaced.

Memory trick: Wet blanket on a roof, bad news from the start.

The California Building Code (CBC) generally limits asphalt shingle roofs to a maximum of two layers before a complete tear-off is required.

• Applies to asphalt shingles.
• Prevents excessive weight load on structure.
• Ensures proper substrate for new roofing.

Memory trick: Two layers are fine, but three means tear-off time.

For hot-applied roofing, a fire watch must be maintained for at least 30 minutes after operations cease to prevent delayed ignition.

• Required for hot-applied roofing and other hot work.
• Monitors for smoldering materials or hidden fires.
• Minimum duration is typically 30 minutes after work stops.

Memory trick: Hot mop needs a keen eye, even after the work is done, to prevent a fiery surprise.

Ladder side rails must extend at least 3 feet above the upper landing surface for safe access.

• Applies to ladders used for accessing elevated surfaces.
• Provides a stable handhold for stepping on/off the ladder.
• Aids in maintaining balance during transition.

Memory trick: Three feet high, for a safe sky.

Calculating the total roof surface area by first adjusting the building's footprint for any overhangs, then applying the appropriate slope factor, and finally converting to roofing squares.

• Overhangs increase the effective footprint dimensions.
• Slope factors account for the roof's pitch.
• 1 square = 100 square feet.

Memory trick: Overhangs first, then Slope, then Squares, like building a house layer by layer.

The use of a slope factor to convert a roof's flat plan (footprint) area into its actual surface area, which is necessary for accurate material takeoffs.

• Slope factors account for the increased surface area due to roof pitch.
• Different pitches (rise:run) have different slope factors.
• Actual surface area is always greater than or equal to the flat plan area.

Memory trick: Slope Factor is the trick to true roof area, don't miss the rise!

Determining the total number of underlayment rolls needed by considering the roof area, number of layers, net coverage per roll, and an added waste factor.

• Waste factors are essential for accurate material ordering.
• Always round up to the nearest whole roll.
• Net coverage per roll accounts for overlaps.

Memory trick: Layers + Waste = Rolls to order, like a recipe for a perfect cake.

Determining the number of tile courses needed for a given roof slope length by dividing the total length by the tile's effective exposure per course.

• Exposure is the visible portion of a tile.
• Headlap is the portion covered by the next course.
• Always round up to ensure full coverage.

Memory trick: Slope Length divided by Exposure gives Courses, like slicing a loaf of bread.

Calculating the total number of cap sheet rolls required for a low-slope roof by dividing the roof area by the net coverage per roll and then applying a waste factor.

• Net coverage per roll accounts for manufacturer-specified laps.
• Waste factors are crucial for accurate ordering.
• Always round up to the nearest whole roll.

Memory trick: Area to coverage, then add waste, like baking a pie with extra crust.

The minimum net free ventilation area required for an attic space when no vapor retarder is installed, as specified by building codes (typically 1:150 of the attic floor area).

• Code requirement is 1:150 when no vapor retarder.
• Ratio is NFVA (Net Free Ventilation Area) to attic floor area.
• Adequate ventilation prevents moisture buildup and heat issues.

Memory trick: No vapor? 150 is the magic number for fresh air!

The total area of felt underlayment required for a multi-ply built-up roofing system, calculated by multiplying the roof deck area by the number of plies.

• 1 square = 100 square feet
• Each ply adds one layer of felt coverage
• Waste factors are typically added after this calculation

Memory trick: BUR is like a BLT sandwich, layers for strength.

Saturated roof insulation must be removed and replaced during reroofing projects because it loses its thermal effectiveness, promotes mold growth, and can cause structural damage.

• Saturated insulation loses R-value.
• Trapped moisture can lead to mold and rot.
• Replacement is critical for roof system integrity.

Memory trick: Wet Insulation: Remove, Replace, Re-insulate wisely, or Regret it later.