NRCA ProCertified Asphalt Shingle Installer cheat sheet

OSHA 29 CFR 1926.501(b)(13): residential roofers must use fall protection when working at heights of 6 feet or more above a lower level, or when exposed to a fall hazard of 6 feet or more.

Guardrail systems must be 42 inches (±3 inches) high with a midrail at 21 inches; top rails must withstand a 200-pound force applied in any outward or downward direction.

Personal fall arrest systems (PFAS): anchor point must support at least 5,000 pounds per worker, or be designed by a qualified person with a safety factor of at least 2; keep fall distance to a maximum of 6 feet, and never tie off to a chimney, vent pipe, or gutter.

Ladder extension above roof edge: 3 feet minimum; ladder angle: 4:1 ratio (1 foot out for every 4 feet up); secure top and bottom; inspect for damage before each use.

Material handling: keep loads below 50 pounds per worker when possible; use mechanical lifts or hoists for bundles; stage materials at least 6 feet back from the roof edge on low-slope roofs.

Roof slope safety: use roof jacks or staging platforms on slopes steeper than 4:12; on slopes steeper than 8:12, use scaffolding or a ladder jack system; never walk on a roof that is wet, icy, or covered with moss.

Electrical hazards: maintain a minimum 10-foot clearance from overhead power lines for tools and materials; use non-conductive ladders near electrical sources; lock out/tag out before working near electrical equipment.

Emergency plan: post a written emergency action plan on site; ensure at least one worker per crew is trained in first aid and CPR; provide a means of summoning emergency services (phone or radio).

Deck inspection: replace any rotted, delaminated, or soft sheathing; ensure all deck boards are securely fastened and free of protruding nails; verify that sheathing is rated for roof use (e.g., OSB or plywood with an appropriate span rating).

Deck thickness: minimum 3/8-inch (nominal) for roof sheathing, but many manufacturers require 15/32-inch or 1/2-inch plywood or OSB for shingle application; always check the shingle manufacturer's requirements.

Roof deck ventilation: provide at least 1 square foot of net free ventilation area per 150 square feet of attic floor space (1/150 ratio) when no vapor retarder is installed; use 1/300 ratio when a vapor retarder is present and balanced intake/exhaust is provided.

Underlayment: use a minimum of one layer of No. 15 asphalt-saturated felt or a synthetic underlayment meeting ASTM D226 or D4869; in high-wind or ice-dam areas, use a peel-and-stick membrane along eaves.

Ice dam protection: in areas where average January temperature is 30°F or below, install a self-adhering ice dam membrane from the eave edge up the roof to a point at least 24 inches inside the exterior wall line.

Valley underlayment: install a minimum 36-inch-wide strip of underlayment centered on the valley, or use a self-adhering membrane; overlap underlayment in valleys according to manufacturer instructions.

Drip edge: install a metal drip edge at eaves and gables; at eaves, place underlayment over the drip edge; at gables, place drip edge over underlayment, unless manufacturer specifies otherwise.

Deck fastening: use ring-shank or screw-shank nails; space 6 inches on center along panel edges and 12 inches on center in the field; fasteners must penetrate at least 3/4 inch into framing.

Fastener type: use galvanized, zinc-coated, or aluminum roofing nails with a minimum head diameter of 3/8 inch and a minimum shank diameter of 12 gauge (0.105 inch); staples are not permitted unless allowed by the manufacturer and code.

Fastener placement: position nails 1/4 to 1/2 inch above the top edge of the shingle's exposure line (the adhesive strip area) and 1 inch from each end; drive nails straight and flush with the shingle surface-do not overdrive or underdrive.

Number of fasteners: for slopes less than 20 degrees (4:12), use 4 nails per shingle; for slopes of 20 degrees or more, use 6 nails per shingle; in high-wind areas, use 6 nails and follow manufacturer's high-wind nailing pattern.

Starter course: install a manufacturer-approved starter strip along the eaves and rake edges; starter shingles must overhang the drip edge by 1/4 to 3/8 inch; never use cut-up regular shingles as starter unless approved.

Shingle alignment: offset joints at least 6 inches from the underlying course; maintain a consistent exposure (typically 5 inches for 3-tab, 5-5/8 to 8 inches for architectural) as specified by the manufacturer.

Adhesive strip: ensure the adhesive strip is not covered by the overlapping shingle's nails; in cold weather, apply a dab of asphalt roof cement under each tab to secure them until the sun activates the sealant.

Hip and ridge: install hip and ridge shingles with a minimum 1-inch overlap on each side; nail on each side, 1 inch from the edge; exposure should be 5 to 6 inches unless manufacturer specifies otherwise.

High-wind areas: use six nails per shingle and apply a continuous bead of asphalt roof cement along the rake edges and under the tabs of the first course; follow manufacturer's wind warranty requirements.

Valley flashing: open valleys require a minimum 24-inch-wide metal flashing (or 36-inch-wide for some manufacturers) centered in the valley; closed valleys use a valley lining under the shingles; never nail through the center of the valley flashing.

Valley installation: for open valleys, install the metal flashing over the underlayment, then weave or cut the shingles so that water flows over the flashing; for closed valleys, cut the shingles along the valley centerline and seal with cement.

Step flashing: use minimum 4-inch by 4-inch by 8-inch L-shaped step flashing at sidewalls; each piece must extend at least 4 inches up the wall and 4 inches onto the roof; overlap each piece by at least 2 inches; never use continuous flashing at sidewalls.

Chimney flashing: install a cricket (saddle) on the back side of chimneys wider than 30 inches; use base flashing, step flashing, and counterflashing; counterflashing must be embedded at least 1 inch into the masonry and sealed.

Skylight flashing: follow the skylight manufacturer's instructions; typically, use a curb-mounted skylight with step flashing on sides and head flashing at the top; seal all fasteners with approved sealant.

Pipe penetrations: use a neoprene or lead boot that fits the pipe diameter; slide the boot over the pipe, set the flange in asphalt roof cement, and fasten the flange with nails at the edges; the top half of the boot should be under the shingle above and the bottom half over the shingle below.

Drip edge at gables: install drip edge over the underlayment at rake edges; at eaves, install drip edge under the underlayment; fasten with roofing nails spaced 12 inches on center.

Kick-out flashing: at the bottom of a sidewall where it meets a roof, install a kick-out flashing to divert water away from the wall; the kick-out must extend at least 4 inches above the roof and be sealed to the wall.

Ventilation ratio: 1 square foot of net free ventilating area (NFVA) per 150 square feet of attic floor area when no vapor retarder is present; 1/300 when a vapor retarder is installed and balanced intake/exhaust is provided.

Balance intake and exhaust: provide at least 50% of the required NFVA as intake (soffit) vents and the remainder as exhaust (ridge or gable) vents; exhaust vents should be located high on the roof and intake low at the eaves.

Ridge vent: install continuous ridge vent along the ridge; net free area varies by product; ensure the vent is rated for the roof slope and that the opening is cut to the manufacturer's width (typically 1.5 to 2 inches on each side of the ridge).

Soffit vents: ensure soffit vents are not blocked by insulation; use baffles to maintain a 1-inch clear air channel between insulation and roof deck; blocked soffits reduce intake and can cause moisture problems.

Vapor retarder: in cold climates, install a vapor retarder on the warm side of the insulation (typically the ceiling); in warm, humid climates, a vapor retarder may not be required or may be placed differently; follow local code.

Moisture control: roof deck must be dry before installing underlayment and shingles; avoid installing shingles over wet decking; use a moisture meter to verify wood moisture content is below 19%.

Condensation: in cold weather, warm moist air from the house can condense on the underside of the roof deck; proper ventilation and air sealing of the ceiling plane reduce condensation and prevent ice dams.

Attic ventilation code: IRC R806 requires ventilation of enclosed attics and rafter spaces; exceptions exist for attics with a vapor retarder and other conditions; always verify local amendments.

Manufacturer instructions: always follow the shingle manufacturer's written installation instructions; they are the primary source for nailing patterns, exposure, underlayment requirements, and warranty conditions.

Code adoption: the International Residential Code (IRC) Chapter 9 and International Building Code (IBC) Chapter 15 govern roof assemblies; local jurisdictions may adopt amended versions; verify the applicable code edition for the project.

ASTM standards: shingles must meet ASTM D3462 (asphalt shingles made from glass felt) or ASTM D225 (asphalt shingles); underlayment must meet ASTM D226 or D4869; fasteners must meet ASTM F1667.

Wind resistance: shingles are classified by wind resistance (e.g., Class D, G, or H) per ASTM D3161 or UL 997; installation must match the classification's required nailing pattern and adhesive application.

Fire rating: asphalt shingles are typically Class A, B, or C per UL 790 or ASTM E108; the roof assembly rating depends on the shingles, underlayment, and deck combination; do not substitute materials without verifying the rating.

Warranty compliance: failure to follow manufacturer instructions (e.g., using fewer nails, improper underlayment, or installing in cold weather without sealant) can void the warranty; document installation practices with photos.

Product approvals: check for ICC-ES evaluation reports or local product approvals; some jurisdictions require specific product listings for fire, wind, or impact resistance.

Jobsite documentation: keep a copy of the manufacturer's instructions and the applicable code sections on site; record product labels and lot numbers for traceability.

Inspection checklist: check for missing, cracked, or curled shingles; exposed nails; damaged flashing; clogged valleys; deteriorated sealant; and signs of leaks in the attic (stains, mold, or daylight).

Common defects: nail pops (fastener backing out), overdriven nails (breaking the shingle mat), underdriven nails (holding shingle above the deck), and improper nailing location (above the adhesive strip) are frequent causes of wind damage.

Hail damage: look for circular bruises or soft spots on shingles; hail hits may remove granules and expose the asphalt; use a chalk circle to mark and photograph damage for insurance claims.

Wind damage: check for lifted or missing shingles, especially at ridges, hips, and eaves; determine if the adhesive strip failed or if nails were insufficient; repair by replacing damaged shingles and re-sealing.

Leak detection: use a water test or infrared camera to locate leaks; check attic side for water stains and follow the path of water; common leak points are valleys, penetrations, and sidewalls.

Repair procedure: remove damaged shingles by cutting around them with a hook blade; install new shingles matching the existing exposure; nail in the same pattern; apply asphalt cement to seal tabs; ensure the repair blends with the existing roof.

Granule loss: excessive granule loss in gutters or at downspouts may indicate aging or manufacturing defects; some granule loss is normal, but large bare spots require replacement.

Documentation: photograph all defects before repair; record measurements (e.g., slope, area) and materials used; provide a written report to the homeowner with recommendations.

Contract requirements: provide a written contract that includes scope of work, materials (manufacturer, product line, color), start and completion dates, payment schedule, warranty terms, and a statement of the right to cancel.

Change orders: any change to the scope, materials, or schedule must be documented in a written change order signed by both parties before work proceeds.

Communication: maintain a single point of contact for the homeowner; provide daily or weekly progress updates; respond to concerns within 24 hours; keep a log of all communications.

Jobsite cleanliness: remove all debris (old shingles, nails, packaging) at the end of each workday; use a magnetic sweeper to pick up nails; protect landscaping and siding with tarps.

Safety documentation: keep a written safety plan on site; conduct daily toolbox talks; record attendance; report all incidents and near misses; maintain OSHA required records (e.g., OSHA 300 log for larger crews).

Warranty documentation: provide the homeowner with the manufacturer's warranty and the contractor's workmanship warranty in writing; explain coverage, exclusions, and maintenance requirements.

Final inspection: walk the roof with the homeowner; demonstrate proper drainage; provide a maintenance schedule; obtain a signed completion certificate and final payment.

Record keeping: retain copies of permits, inspection reports, material receipts, and photographs for at least the warranty period; these documents protect both the contractor and the homeowner.