AL Roofing Contractor cheat sheet

Asphalt shingle weights: 3-tab ~240 lb/square; laminated (architectural) ~300-480 lb/square depending on product.

Mineral-surfaced cap sheet and base sheet for modified bitumen are specified by ASTM D6162/D6163 (SBS) and D6164 (APP).

Clay and concrete tile are classified by ASTM C1167 (clay) and C1492 (concrete) with freeze-thaw grades; Grade 1 is the highest weathering grade.

Metal roofing panels: standing seam uses concealed clips; panel width, seam height, and gauge (commonly 24-26 ga steel) determine wind uplift rating.

Under ASTM D7158, asphalt shingle wind ratings are Class D (90 mph), G (120 mph), or H (150 mph).

Slope rules: low-slope is 2:12 to 4:12; steep-slope is >4:12; most shingles require minimum 4:12 with double underlayment below 4:12 per manufacturer.

SPF (spray polyurethane foam) roofing density typically 2.5-3.0 lb/ft3 for roof applications; requires protective coating for UV exposure.

EPDM and TPO membranes are single-ply; TPO heat-welded seams, EPDM adhesive or tape seams; membrane thickness commonly 45-90 mil.

Shingle exposure is set by manufacturer; common 3-tab exposure is 5 in. with 12-in. shingles giving 60 shingles per square.

Fastener pattern: 4 nails per shingle standard; 6 nails in high-wind zones; nails placed in nail line 1 in. above exposure line.

Valley treatment: open metal valley or woven/cut valley per manufacturer; closed-cut valley is the most common for asphalt shingles.

Ice dam protection membrane required in areas subject to ice damming; typically extends from eave up 24 in. inside the exterior wall line.

Starter course required at eaves and rake edges; hip and ridge caps installed over the ridge with 5-6 in. exposure.

Nail penetration into new deck must be at least 3/4 in.; overdriven nails are a defect and must be corrected.

Metal roof panel clip spacing and fastener spacing are set by the manufacturer's engineering report; uplift ratings per UL 580 or ASTM E1592.

Tile roofing requires a minimum 2:12 slope with underlayment; low-slope tile systems use a built-up or single-ply underlayment.

Wood roof deck: minimum 15/32-in. or 1/2-in. plywood/OSB for shingles; 5/8-in. recommended where span exceeds 24 in. o.c.

Decking must be gapped 1/8 in. for expansion unless tongue-and-groove; gaps allow drainage and prevent buckling.

Underlayment: No. 15 felt (ASTM D226 Type I) or No. 30 felt (Type II); synthetic underlayment per ASTM D8257.

Ice barrier membrane per ASTM D1970 self-adhering; applied to eaves and valleys in cold climates.

Step flashing required at sidewalls; each shingle course laps the step flashing; base flashing at roof-to-wall intersection.

Counterflashing is embedded in masonry or attached to wall; must overlap base flashing a minimum of 4 in.

Drip edge per ASTM D4637 or manufacturer; required at eaves and rakes to direct water away from fascia.

Pipe boots and vent flashing must be compatible with the roof material; lead boots for tile and metal, neoprene for shingle.

Roof dead load for asphalt shingles ~2-3 psf; tile 9-12 psf; metal 1-3 psf; SPF 2-3 psf at 1-in. thickness.

Live load for roofs: 20 psf minimum for ordinary roofs; 12 psf for certain low-slope per ASCE 7.

Rafter span tables (e.g., IRC Table R802.5.1) give allowable spans based on species, grade, size, and spacing.

Ridge board must be sized to support rafter loads; hip and valley rafters sized per IRC Table R802.5.1(7)-(9).

Collar ties in upper third of rafter span; rafter ties in lower third; ceiling joists resist outward thrust.

Roof slope expressed as rise:run; pitch angle = arctangent(rise/run); slope factor = sqrt(rise^2+run^2)/run.

Wind uplift per ASCE 7 Chapter 30 for components and cladding; edge and corner zones have higher uplift.

Truss design and repair must be by a registered design professional; field modifications require sealed truss repair drawings.

Roof area = plan area x slope factor; slope factor for 4:12 = 1.054, 6:12 = 1.118, 8:12 = 1.202, 12:12 = 1.414.

One roofing square = 100 sq ft; bundle count = squares x bundles per square (3 bundles per square for most 3-tab).

Waste factor: 10% for simple gable, 15% for hips/valleys, up to 20% for complex roofs.

Linear feet of eave, rake, ridge, hip, and valley are measured separately for trim and flashing takeoff.

Specifications hierarchy: plans govern dimensions; specs govern materials and workmanship; RFI resolves conflicts.

Unit price estimate total = sum of (quantity x unit cost) + overhead + profit + contingency.

Plan symbols: dashed lines indicate concealed or overhead items; section markers reference detail drawings.

Addenda modify bid documents before bid opening; change orders modify after contract execution.

Common business forms: sole proprietorship, partnership, LLC, corporation; LLC and corporation limit personal liability.

Contractor license typically requires qualifying party exam, proof of insurance, and continuing education.

General liability insurance minimums commonly $1,000,000 per occurrence / $2,000,000 aggregate for roofing contractors.

Workers' compensation required when employees exist; sole proprietors and partners often exempt but may elect coverage.

Bid bonds, performance bonds, and payment bonds are three distinct surety instruments; public works often require all three.

A qualifying party is the licensed individual who passes the trade exam and is responsible for the licensee's work.

License reciprocity between states varies; most require the qualifying party to hold a license in that state.

Contractor registration and license numbers must appear on contracts, bids, and advertising in most jurisdictions.

A contract requires offer, acceptance, consideration, capacity, and legality; mutual assent is essential.

Mechanic's lien rights typically require preliminary notice and a lien filing within a statutory period after last furnishing labor or materials.

Three-day right of rescission applies to certain door-to-door or home solicitation contracts under federal and state law.

Implied warranty of workmanlike performance attaches to construction contracts; express warranties are written terms.

Indemnification clauses shift risk; some states void indemnification for a party's own negligence (anti-indemnity statutes).

Statute of limitations for written contracts is commonly 4-6 years; for construction defects, statutes of repose commonly 6-10 years.

Change orders must be in writing and signed by both parties to be enforceable and to modify contract price or time.

Notice and opportunity to cure provisions are required in many consumer protection statutes before litigation.

OSHA fall protection for roofing: guardrail, safety net, or personal fall arrest system at 6 ft or more above lower level (29 CFR 1926.501).

Ladder rule: 4:1 slope; extend 3 ft above landing; secure top and bottom; 3-point contact when climbing.

Personal fall arrest system: full-body harness, lanyard, anchor; anchor rated 5,000 lb per worker or engineered 2:1 safety factor.

Scaffold requirements: 10 ft or more requires design by competent person; guardrails at 42 in. top rail, 21 in. midrail.

Head protection required where overhead hazards exist; ANSI Z89.1 hard hats; eye protection for cutting and nailing.

Hazard communication (HazCom) per 29 CFR 1926.59; SDS sheets required for chemicals including adhesives and sealants.

Heat illness prevention: water, rest, shade; acclimatization for new workers; watch for heat stroke symptoms.

Silica dust exposure from cutting tile or concrete requires wet cutting or respirator per 29 CFR 1926.1153.

IRC Chapter 9 covers roof assemblies; IBC Chapter 15 covers roof assemblies and rooftop structures.

ASTM D3462 covers asphalt shingles; ASTM D7158 covers wind resistance; ASTM D3161 covers wind resistance of shingles.

UL 790 / ASTM E108 classify roof coverings by fire resistance: Class A, B, or C.

IRC R905 covers roof covering requirements including slope, underlayment, and flashing.

Permits required for re-roofing in most jurisdictions; inspections at deck, underlayment, and final stages.

Energy code (IECC) may require cool roof rated per CRRC for low-slope roofs in climate zones.

Fire-rated assemblies: roof-ceiling assemblies rated per UL or GA; penetrations must maintain fire rating.

Manufacturer installation instructions are part of the code requirement; installation not per manufacturer can void warranty and fail inspection.

Gross profit = revenue - direct job costs; net profit = gross profit - overhead.

Overhead is indirect cost (office, insurance, vehicles); job cost includes labor, materials, equipment, and subcontractors.

Retainage commonly 5-10% withheld until substantial completion; track as receivable.

Payroll taxes: FICA (6.2% Social Security up to wage base, 1.45% Medicare), FUTA 0.6% on first $7,000, SUTA per state.

Form 941 filed quarterly for federal payroll; Form 940 annually for FUTA; W-2 to employees by January 31.

1099-NEC issued to independent contractors paid $600 or more; misclassification risk if worker is treated as employee.

Cash flow: billing cycle, progress payments, and retainage affect working capital; retainage receivable is an asset.

Break-even revenue = fixed overhead / gross margin percentage.

Asphalt shingle weights: 3-tab ~240 lb/square; laminated (architectural) ~300-480 lb/square depending on product.

Mineral-surfaced cap sheet and base sheet for modified bitumen are specified by ASTM D6162/D6163 (SBS) and D6164 (APP).

Clay and concrete tile are classified by ASTM C1167 (clay) and C1492 (concrete) with freeze-thaw grades; Grade 1 is the highest weathering grade.

Metal roofing panels: standing seam uses concealed clips; panel width, seam height, and gauge (commonly 24-26 ga steel) determine wind uplift rating.

Under ASTM D7158, asphalt shingle wind ratings are Class D (90 mph), G (120 mph), or H (150 mph).

Slope rules: low-slope is 2:12 to 4:12; steep-slope is >4:12; most shingles require minimum 4:12 with double underlayment below 4:12 per manufacturer.

SPF (spray polyurethane foam) roofing density typically 2.5-3.0 lb/ft3 for roof applications; requires protective coating for UV exposure.

EPDM and TPO membranes are single-ply; TPO heat-welded seams, EPDM adhesive or tape seams; membrane thickness commonly 45-90 mil.

Shingle exposure is set by manufacturer; common 3-tab exposure is 5 in. with 12-in. shingles giving 60 shingles per square.

Fastener pattern: 4 nails per shingle standard; 6 nails in high-wind zones; nails placed in nail line 1 in. above exposure line.

Valley treatment: open metal valley or woven/cut valley per manufacturer; closed-cut valley is the most common for asphalt shingles.

Ice dam protection membrane required in areas subject to ice damming; typically extends from eave up 24 in. inside the exterior wall line.

Starter course required at eaves and rake edges; hip and ridge caps installed over the ridge with 5-6 in. exposure.

Nail penetration into new deck must be at least 3/4 in.; overdriven nails are a defect and must be corrected.

Metal roof panel clip spacing and fastener spacing are set by the manufacturer's engineering report; uplift ratings per UL 580 or ASTM E1592.

Tile roofing requires a minimum 2:12 slope with underlayment; low-slope tile systems use a built-up or single-ply underlayment.

Wood roof deck: minimum 15/32-in. or 1/2-in. plywood/OSB for shingles; 5/8-in. recommended where span exceeds 24 in. o.c.

Decking must be gapped 1/8 in. for expansion unless tongue-and-groove; gaps allow drainage and prevent buckling.

Underlayment: No. 15 felt (ASTM D226 Type I) or No. 30 felt (Type II); synthetic underlayment per ASTM D8257.

Ice barrier membrane per ASTM D1970 self-adhering; applied to eaves and valleys in cold climates.

Step flashing required at sidewalls; each shingle course laps the step flashing; base flashing at roof-to-wall intersection.

Counterflashing is embedded in masonry or attached to wall; must overlap base flashing a minimum of 4 in.

Drip edge per ASTM D4637 or manufacturer; required at eaves and rakes to direct water away from fascia.

Pipe boots and vent flashing must be compatible with the roof material; lead boots for tile and metal, neoprene for shingle.

Roof dead load for asphalt shingles ~2-3 psf; tile 9-12 psf; metal 1-3 psf; SPF 2-3 psf at 1-in. thickness.

Live load for roofs: 20 psf minimum for ordinary roofs; 12 psf for certain low-slope per ASCE 7.

Rafter span tables (e.g., IRC Table R802.5.1) give allowable spans based on species, grade, size, and spacing.

Ridge board must be sized to support rafter loads; hip and valley rafters sized per IRC Table R802.5.1(7)-(9).

Collar ties in upper third of rafter span; rafter ties in lower third; ceiling joists resist outward thrust.

Roof slope expressed as rise:run; pitch angle = arctangent(rise/run); slope factor = sqrt(rise^2+run^2)/run.

Wind uplift per ASCE 7 Chapter 30 for components and cladding; edge and corner zones have higher uplift.

Truss design and repair must be by a registered design professional; field modifications require sealed truss repair drawings.

Roof area = plan area x slope factor; slope factor for 4:12 = 1.054, 6:12 = 1.118, 8:12 = 1.202, 12:12 = 1.414.

One roofing square = 100 sq ft; bundle count = squares x bundles per square (3 bundles per square for most 3-tab).

Waste factor: 10% for simple gable, 15% for hips/valleys, up to 20% for complex roofs.

Linear feet of eave, rake, ridge, hip, and valley are measured separately for trim and flashing takeoff.

Specifications hierarchy: plans govern dimensions; specs govern materials and workmanship; RFI resolves conflicts.

Unit price estimate total = sum of (quantity x unit cost) + overhead + profit + contingency.

Plan symbols: dashed lines indicate concealed or overhead items; section markers reference detail drawings.

Addenda modify bid documents before bid opening; change orders modify after contract execution.

Common business forms: sole proprietorship, partnership, LLC, corporation; LLC and corporation limit personal liability.

Contractor license typically requires qualifying party exam, proof of insurance, and continuing education.

General liability insurance minimums commonly $1,000,000 per occurrence / $2,000,000 aggregate for roofing contractors.

Workers' compensation required when employees exist; sole proprietors and partners often exempt but may elect coverage.

Bid bonds, performance bonds, and payment bonds are three distinct surety instruments; public works often require all three.

A qualifying party is the licensed individual who passes the trade exam and is responsible for the licensee's work.

License reciprocity between states varies; most require the qualifying party to hold a license in that state.

Contractor registration and license numbers must appear on contracts, bids, and advertising in most jurisdictions.

A contract requires offer, acceptance, consideration, capacity, and legality; mutual assent is essential.

Mechanic's lien rights typically require preliminary notice and a lien filing within a statutory period after last furnishing labor or materials.

Three-day right of rescission applies to certain door-to-door or home solicitation contracts under federal and state law.

Implied warranty of workmanlike performance attaches to construction contracts; express warranties are written terms.

Indemnification clauses shift risk; some states void indemnification for a party's own negligence (anti-indemnity statutes).

Statute of limitations for written contracts is commonly 4-6 years; for construction defects, statutes of repose commonly 6-10 years.

Change orders must be in writing and signed by both parties to be enforceable and to modify contract price or time.

Notice and opportunity to cure provisions are required in many consumer protection statutes before litigation.

OSHA fall protection for roofing: guardrail, safety net, or personal fall arrest system at 6 ft or more above lower level (29 CFR 1926.501).

Ladder rule: 4:1 slope; extend 3 ft above landing; secure top and bottom; 3-point contact when climbing.

Personal fall arrest system: full-body harness, lanyard, anchor; anchor rated 5,000 lb per worker or engineered 2:1 safety factor.

Scaffold requirements: 10 ft or more requires design by competent person; guardrails at 42 in. top rail, 21 in. midrail.

Head protection required where overhead hazards exist; ANSI Z89.1 hard hats; eye protection for cutting and nailing.

Hazard communication (HazCom) per 29 CFR 1926.59; SDS sheets required for chemicals including adhesives and sealants.

Heat illness prevention: water, rest, shade; acclimatization for new workers; watch for heat stroke symptoms.

Silica dust exposure from cutting tile or concrete requires wet cutting or respirator per 29 CFR 1926.1153.

IRC Chapter 9 covers roof assemblies; IBC Chapter 15 covers roof assemblies and rooftop structures.

ASTM D3462 covers asphalt shingles; ASTM D7158 covers wind resistance; ASTM D3161 covers wind resistance of shingles.

UL 790 / ASTM E108 classify roof coverings by fire resistance: Class A, B, or C.

IRC R905 covers roof covering requirements including slope, underlayment, and flashing.

Permits required for re-roofing in most jurisdictions; inspections at deck, underlayment, and final stages.

Energy code (IECC) may require cool roof rated per CRRC for low-slope roofs in climate zones.

Fire-rated assemblies: roof-ceiling assemblies rated per UL or GA; penetrations must maintain fire rating.

Manufacturer installation instructions are part of the code requirement; installation not per manufacturer can void warranty and fail inspection.

Gross profit = revenue - direct job costs; net profit = gross profit - overhead.

Overhead is indirect cost (office, insurance, vehicles); job cost includes labor, materials, equipment, and subcontractors.

Retainage commonly 5-10% withheld until substantial completion; track as receivable.

Payroll taxes: FICA (6.2% Social Security up to wage base, 1.45% Medicare), FUTA 0.6% on first $7,000, SUTA per state.

Form 941 filed quarterly for federal payroll; Form 940 annually for FUTA; W-2 to employees by January 31.

1099-NEC issued to independent contractors paid $600 or more; misclassification risk if worker is treated as employee.

Cash flow: billing cycle, progress payments, and retainage affect working capital; retainage receivable is an asset.

Break-even revenue = fixed overhead / gross margin percentage.