MI Roofing Contractor flashcards
MI Roofing Contractor · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Roof slope formula
- Slope is rise divided by run, expressed as inches of vertical rise per 12 inches of horizontal run; for example, 4:12 means 4 inches rise per 12 inches run.
- Pitch multiplier
- For a roof with rise r per 12, the pitch multiplier is the square root of (12² + r²) divided by 12; multiply plan area by it to estimate sloped area.
- Roofing square
- A roofing square is 100 square feet of roof surface. Divide total roof area in square feet by 100 to determine the number of squares for ordering.
- Net free vent area
- Attic ventilation requires net free vent area of at least 1/150 of the attic floor area; 1/300 is allowed when a vapor retarder and balanced intake and exhaust vents are installed.
- Asphalt shingle composition
- Fiberglass mat saturated and coated with asphalt, then surfaced with mineral granules; the mat provides strength and granules protect asphalt from ultraviolet light.
- Ice-and-water shield
- A self-adhering waterproof membrane installed at eaves and valleys; it seals around fasteners and resists ice-dam backup. It extends at least 24 inches inside the exterior wall line.
- Galvanic corrosion
- Dissimilar metals in contact with moisture can create an electrical current that corrodes one metal; avoid joining aluminum and copper or use compatible separators.
- Drip edge function
- A corrosion-resistant metal flashing at roof edges that directs water away from fascia and into gutters, protecting sheathing and siding from water damage.
- Underlayment lap
- Asphalt felt underlayment is lapped at least 2 inches on sides and 4 inches at ends, with upper layers overlapping lower layers so water sheds downslope.
- Step flashing
- L-shaped metal pieces woven with siding and shingles at sidewalls and chimneys; each piece overlaps the one below to shed water away from the wall.
- Starter strip
- A first row of shingles or purpose-made starter at eaves and rakes that seals shingle edges and helps resist wind uplift; it is installed before the first full course.
- Valley flashing
- Metal or membrane lining in a roof valley that carries concentrated runoff; it is installed before shingles and must extend under shingles on both slopes.
- Repair versus replacement
- Replacement is indicated when leaks are widespread, shingles are brittle or losing granules, or decking is damaged; isolated defects can be repaired.
- Ice dam cause
- Ice dams form when warm attic air melts snow that refreezes at the cold eave; water backs up under shingles. Fix by air sealing, insulation, and ventilation.
- Emergency roof tarp
- A temporary cover secured over a leak to prevent further water entry; fasten without creating new holes and remove or replace before permanent repair.
- Flashing leak diagnosis
- Check wall intersections, valleys, penetrations, and chimneys first; most leaks originate at flashings or fasteners rather than the field of shingles.
- Michigan Residential Code
- The state code for one- and two-family dwellings and townhouses, based on the International Residential Code with Michigan amendments; it governs roofing, ventilation, and energy provisions.
- Roof replacement permit
- Most Michigan local building departments require a permit before replacing a roof covering; ordinary repairs may be exempt, so verify with the authority having jurisdiction.
- Ice barrier code trigger
- The residential code requires an ice barrier at eaves where the average January temperature is 25°F or lower, which includes most of Michigan.
- Michigan roofing license
- Michigan does not issue a separate roofing license; residential roofing contractors generally need a Residential Builder or Maintenance and Alteration Contractor license from the state licensing agency.
- Break-even revenue
- Fixed costs divided by gross margin percentage gives the sales revenue needed to cover overhead before profit; it helps set minimum monthly sales targets.
- Markup versus margin
- Margin is profit divided by selling price; markup is profit divided by cost. Convert margin to markup with markup = margin ÷ (1 − margin).
- Labor burden
- The extra cost above base wages, including payroll taxes, workers compensation, insurance, and benefits; add it to hourly wage when estimating labor cost.
- Job costing
- Tracking actual labor, material, equipment, and subcontractor costs by project; comparing actual to estimated costs reveals profit or loss on each job.
- Roof takeoff
- A quantity survey of roof areas, edges, valleys, penetrations, and flashings, converted to squares and linear feet; add waste and accessories before pricing.
- Written change order
- A signed document describing a scope change, its price, and schedule effect before work proceeds; it prevents disputes and supports payment for extra work.
- Workmanship warranty
- A contractor's written promise to repair installation defects for a stated period; it is separate from manufacturer material warranties and should define exclusions.
- Construction lien
- A legal claim against property for unpaid labor or materials; contractors must follow statutory notice and recording deadlines to preserve the right.
- Fall protection threshold
- OSHA construction rules generally require fall protection when workers are exposed to falls of 6 feet or more, using guardrails, nets, or personal fall arrest.
- Ladder setup angle
- Set extension ladders at about a 4:1 ratio, one foot out from the wall for every four feet of working height, and extend 3 feet above the landing.
- Personal fall arrest anchor
- An anchor for personal fall arrest must support at least 5,000 pounds per worker or be designed by a qualified person and used with a full-body harness.
- Scaffold guardrail height
- Scaffold guardrails are typically 42 inches high with a midrail near 21 inches and toe boards; fall protection is required at 10 feet or more.