Exam Cheat Sheet · Quick Reference

South Carolina Roofing

South Carolina  ·  PSI Services Contractor

Verified, not estimated. Every figure below is drawn from the official exam structure we maintain — question counts, passing standard and topic weighting. Practice questions are grounded in the source law with statute citations. We omit any figure we can't verify rather than guess at it.
Total questions
65
Passing score
70%
Exam time
180 min
Administered by
PSI Services Contractor
Format
Reference materials allowed

South Carolina State Portion 65 questions

Safety 5 Q · 8%
Fall protection requirements for roofing work (low-slope and steep roofs)Personal fall arrest system components, criteria, and inspectionGuardrail system specifications and requirementsWarning line systems and safety monitoring systems for roofingScaffold safety requirements, capacity, and fall protectionLadder and stairway safety requirements and proper usePersonal protective equipment selection, use, and employer obligationsFire protection, fire prevention, and flammable liquid storage on job sites
Roofing - Substrate 8 Q · 12%
Types of roof deck materials (wood panels, wood planks/boards, steel, structural concrete, lightweight insulating concrete, cementitious wood fiber)Plywood and OSB panel specifications, grading standards, and minimum thickness requirements by rafter spacingRoof deck structural requirements (dead and live load support, deflection limits, fastener withdrawal resistance)Pre-installation deck inspection requirements and surface condition standardsWood deck treatment considerations (preservative-treated and fire-retardant-treated panels)Steel deck configurations, gauges, and attachment to supporting membersLightweight insulating concrete deck design, venting, drying, and curing requirementsSlope and drainage requirements for roof decks by roof system type and applicable building code minimums
Roofing - Steep 22 Q · 34%
Asphalt shingle types, materials, and ratings (UL/ASTM fire and wind classifications)Steep-slope roof deck types, requirements, and minimum slopes by covering materialUnderlayment types, configurations, and selection by roof covering and slopeFlashings and construction details (valley, eave, drip edge, step, counter, cricket/saddle)Clay and concrete tile profiles, materials, attachment methods, and batten systemsSlate roofing materials, grades, sizing, exposure, and installation requirementsWood shakes and shingles: types, grades, interlayment, and application methodsMetal shingles: materials, coatings, attachment, and dissimilar metal considerations
Roofing - Metal Panel 6 Q · 9%
Architectural vs. structural metal panel roof system classifications and minimum slope requirementsMetal types and corrosion resistance (galvanized, Galvalume, aluminum, copper, stainless steel)Panel profiles, seam types, and seaming methods (standing seam, flat seam, batten seam, snap-lock)Fastener selection, compatibility, and wind-uplift attachment requirementsUnderlayment materials and installation for architectural metal panel systemsStructural substrates for metal panel roof systems (steel deck, wood panels, purlins, cold-formed framing)Flashing, closures, and construction details for ridges, eaves, rakes, valleys, and penetrationsReroofing procedures including evaluation of existing systems, re-cover vs. replacement, and building code compliance
Roofing - Metal Flashing 8 Q · 12%
Metal types and properties for flashing (aluminum, copper, galvanized steel, Galvalume, stainless steel, zinc, lead, lead-coated copper)Dissimilar metals and galvanic corrosion preventionThermal expansion and contraction of flashing metalsProtective coatings for metal flashing (fluoropolymer, anodizing, siliconized polyester, paint systems)Metal thickness and gauge requirements by flashing application and roof typeCopings, counterflashings, and perimeter edge metal for low-slope roof systemsValley metal, drip edge, gutters, and downspouts for steep-slope roof systemsWind uplift resistance and ANSI/SPRI ES-1 testing requirements for edge-metal systems
Roofing Repairs 4 Q · 6%
Leak detection and diagnosis methods (interior inspection, attic inspection, tracing water travel)Roof condition assessment and evaluation procedures (re-cover vs. replacement decision)Material-specific repair techniques (asphalt shingles, wood shakes/shingles, slate, tile, metal panels, membrane, SPF)Flashing repair and replacement (base flashings, counterflashings, valley flashings, penetration flashings, drip edge)Roof deck inspection and repair (wood panels, steel deck, deterioration, substrate preparation)Reroofing code requirements under SC Building Code Chapter 15 and IBC Section 1512 (re-cover limitations, layer restrictions, prohibited substrates)Moisture detection in existing roof assemblies (nondestructive methods, core cuts, infrared thermography)Storm and hail damage assessment (identifying hail impact on asphalt shingles, wood roofs, and other coverings)
Roofing - Elastomeric 6 Q · 9%
EPDM membrane properties, types, and installation methods (loosely laid, fully adhered, mechanically fastened)Thermoplastic single-ply membrane types (PVC, CPE, CSPE) and seaming/welding methodsLiquid-applied elastomeric systems including silicone, urethane, and neoprene coatings and application ratesMembrane attachment and ballast systems including wind uplift design and slope limitationsFlashing details and corner flashing techniques for elastomeric membrane systemsSubstrate compatibility, primers, and slip sheet requirements for elastomeric roofingSurfacings and coatings for elastomeric membranes including reflective and protective optionsSC Building Code and IBC requirements for single-ply and membrane roof systems including fire classification and wind resistance testing
Roofing - Built-up Bituminous 6 Q · 9%
Bitumen types and properties (asphalt types I–IV, coal-tar pitch, EVT, flash point, application temperatures)Ply sheets and base sheets (fiberglass, organic, venting base sheets, ASTM standards, lap and exposure requirements)Membrane ply configurations and application methods (two-, three-, four-ply shingle-fashion layout, back-nailing on slopes, brooming-in technique)Substrate compatibility and deck preparation by deck type (metal, concrete, wood/plywood, lightweight insulating concrete, gypsum)BUR surfacing types (aggregate flood coat, smooth glaze coat, mineral-surfaced cap sheet, application rates, code restrictions on aggregate in high-wind areas)Rigid board insulation selection and attachment for BUR assemblies (cover boards, multilayer staggered joints, compatibility with hot bitumen)Membrane and base flashings at penetrations and terminations (parapet walls, cant strips, gravel stops, counterflashing, roof drains, scuppers)SC Building Code and IBC requirements for built-up roofing (minimum slope, fire classification, wind uplift testing, material standards per IBC Section 1507.10)

Key Distinctions

Wood shingles (naturally durable wood)vsWood shakes (naturally durable wood)

Wood shingles may be Grade 1, 2, or 3 under CSSB rules, while wood shakes require a minimum of Grade 1 (taper sawn shakes allow Grade 1 or 2).

IBC 2021 Table 1507.8.5
Positive method of roof measurementvsNegative method of roof measurement

The positive method divides an irregular roof into rectangles and adds their areas, while the negative method extends roof lines into one large rectangle and subtracts the non-roof areas; both yield identical results.

Roofing Construction and Estimating, Chapter 1, Pages 7-8
Cricket at upslope side of chimney/curbvsBacker flashing

NRCA recommends a cricket when the chimney or curbed penetration is more than 24 inches wide; backer flashing is generally limited to penetrations 24 inches wide or less.

NRCA Roofing Manual: Steep-slope Roof Systems (2025), Asphalt Shingle Roof Systems — Chapter 7
Nailing asphalt shingles to wood plank/board decksvsNailing asphalt shingles to plywood decks less than ¾ inch thick

In wood plank or board decks nails must penetrate at least ¾ inch into the deck, whereas in plywood or other wood panels less than ¾ inch thick nails must extend a minimum of ⅛ inch through the underside.

NRCA Roofing Manual: Steep-slope Roof Systems (2025), Section 4.2—Asphalt Shingle Roof System Design and Installation (Fasteners)
ASTM D7158 wind classificationvsASTM D3161 wind classification

ASTM D7158 is a test plus complex calculation procedure (assumptions from ASCE 7-22) yielding basic-wind-speed classes D (≤90 mph), G (≤120 mph), H (≤150 mph), while ASTM D3161 is a fan-induced wind test with Class A at 60 mph, Class D at 90 mph, and Class F at 110 mph.

NRCA Roofing Manual: Steep-slope Roof Systems (2025), Section 4.2—Wind Resistance (ASTM D7158—Calculation Basis)
Drip edge at eavesvsDrip edge at rakes

Per Section 1507.2.8.3, underlayment is installed over the drip edge along eaves (drip edge first), but the drip edge is installed over the underlayment along rake edges (underlayment first).

SC Building Code 2021, Section 1507.2.8.3
Metal roof shinglevsMetal roof panel

A metal roof shingle is an interlocking metal sheet with installed weather exposure less than 3 square feet per sheet; a metal roof panel has a minimum installed weather exposure of 3 square feet or more per sheet.

SC Building Code 2021, Section 202 Definitions — Metal Roof Shingle / Metal Roof Panel
Class A / Class B / Class C roof assembliesvsFire-test exposure level

Class A assemblies are effective against severe fire-test exposure, Class B against moderate exposure, and Class C against light exposure, all tested per ASTM E108 or UL 790.

IBC 2021 Section 1505.2
Copper for preformed metal shingle systemsvsCopper for metal-sheet roof-covering systems

Preformed metal shingle systems require a minimum 12 oz. per sq. ft. copper, while metal-sheet roof-covering systems require 16 oz. per sq. ft. (16 oz./sq. ft. copper over a combustible deck also qualifies as Class A).

IBC 2021 Table 1507.4.3(1)
SPF roof system on new constructionvsSPF roof system on reroofing

New construction SPF requires a minimum slope of ¼:12, whereas reroofing requires only positive drainage rather than the ¼:12 prescriptive slope.

NRCA Roofing Manual: Metal Panel and SPF Roof Systems (2024), SPF Chapter 1, Page 359
Closed-cell SPF air retarder criteria under ASHRAE 90.1vsClosed-cell SPF air retarder criteria under the IECC

ASHRAE 90.1 deemed-to-comply criteria are 2.0 lbs./ft.³ density at a minimum 1 inch thick, while the IECC criteria are 1.5 lbs./ft.³ density at a minimum 1½ inches thick.

NRCA Roofing Manual: Membrane Roof Systems (2023), Page 116
Spaced (skip) sheathing for wood shakesvsSpaced (skip) sheathing for wood shingles

Wood shakes normally use 1 × 6 boards (spacing equal to shake weather exposure) while wood shingles typically use 1 × 4 boards; solid sheathing is required where the average January daily temperature is 25°F (−4°C) or less or ice can back up water at eaves.

Roofing Construction and Estimating, Page 30
Vapor retarder in structural metal panel assembliesvsVapor retarder in architectural metal panel assemblies

In structural metal panel assemblies the vapor retarder is typically a component integrated with the batt insulation below the panels, while in architectural metal panel systems it is typically loose-laid or adhered to the deck or substrate.

NRCA Roofing Manual: Metal Panel and SPF Roof Systems (2024), Page 65
Plywood sheathing over 16-inch o.c. raftersvsPlywood sheathing over 24-inch o.c. rafters

NRCA recommends four-ply nominal ⅝-inch (actual 19/32-inch) plywood at 16-inch rafter spacing and four-ply nominal ¾-inch (actual 23/32-inch) plywood at 24-inch spacing; panel edge clips are recommended when panels ½-inch nominal or less are used over 24-inch spacing.

NRCA Roofing Manual: Steep-slope Roof Systems (2025), Section 2.1—Wood Panels
Slate shingle deckingvsWood shingle/shake decking

Slate shingles must be fastened to solidly sheathed roofs and do not permit spaced sheathing, unlike wood shingles and shakes.

IBC 2021 Section 1507.7.1

Key Terms

Interlayment SC Building Code 2021, Section 202 Definitions — Interlayment
A layer of felt or nonbituminous saturated felt not less than 18 inches wide, shingled between each course of a wood-shake roof covering.
Underlayment SC Building Code 2021, Section 202 Definitions — Underlayment
One or more layers of material applied to a steep-slope roof deck under the roof covering whose defined function is to resist liquid water that has penetrated the roof covering.
Shingle fashion SC Building Code 2021, Section 202 Definitions — Shingle Fashion
A method of installing roof or wall coverings, water-resistive barriers, flashing or other components so upper layers overlap lower layers to provide drainage via gravity and moisture control.
Steep slope (code definition) SC Building Code 2021, Section 202 Definitions — Steep Slope
A roof slope of 2 units vertical in 12 units horizontal (17-percent slope) or greater.
Roof assembly (Chapter 15) SC Building Code 2021, Section 202 Definitions - Roof Assembly
A system designed to provide weather protection and resistance to design loads, consisting of a roof covering and roof deck (or a single component serving as both) and which can include underlayment, a thermal barrier, insulation or a vapor retarder — but not structural framing.
Class A roof assembly IBC 2021 Section 1505.2
A roof assembly effective against severe fire-test exposure; examples include minimum 16 oz./sq. ft. copper sheets over combustible decks and slate over ASTM D226 Type II underlayment over combustible decks.
ASTM D3462 NRCA Roofing Manual: Steep-slope Roof Systems (2025), Section 4.1—Asphalt Shingle Standards
Standard Specification for Asphalt Shingles Made from Glass Felt and Surfaced with Mineral Granules, addressing tear strength, fastener pull-through resistance, and pliability; NRCA recommends specifying fiberglass-reinforced shingles complying with it.
ASTM D3018 NRCA Roofing Manual: Steep-slope Roof Systems (2025), Section 4.1—Asphalt Shingle Standards
Standard Specification for Class A Asphalt Shingles Surfaced with Mineral Granules, addressing fire test classification, wind resistance, and loss of volatile matter after heating.
ASTM D1970 NRCA Roofing Manual: Steep-slope Roof Systems (2025), Section 3.1—Underlayment Materials
Standard Specification for self-adhering polymer-modified bituminous sheet used as steep-roof underlayment for ice dam protection, addressing thickness, tear resistance, adhesion, low-temperature flexibility and thermal stability.
ASTM D8257 NRCA Roofing Manual: Steep-slope Roof Systems (2025), Section 3.1—Underlayment Materials (Synthetic Sheets)
Standard Specification for Mechanically Attached Polymeric Roof Underlayments Used in Steep Slope Roofing — the standard for synthetic sheet underlayments, approved December 2020 and referenced in the 2024 IBC and IRC.
ASTM D4869 NRCA Roofing Manual: Steep-slope Roof Systems (2025), Section 3.1—Underlayment Materials (Asphalt Felts, ASTM D4869)
Standard Specification for Asphalt-Saturated Organic Felt Shingle Underlayment Used in Roofing, with four classifications (Types I–IV); Type II (#13) equals ASTM D226 Type I (No. 15 felt) and Type IV (#26) equals ASTM D226 Type II (No. 30 felt).
ASTM C1167 IBC 2021 Section 1507.3.4
The material standard for clay roof tile, classifying three grades by frost resistance: Grade 1 (severe frost action), Grade 2 (moderate), Grade 3 (negligible resistance).
ASTM C406 IBC 2021 Section 1507.7.5
The material standard with which slate shingles must comply.
ASTM A653 G90 IBC 2021 Table 1507.4.3(2)
The minimum corrosion-resistance standard for zinc-coated (galvanized) steel used in metal roof coverings; ASTM A792 AZ 50 covers aluminum-zinc alloy coated steel and ASTM A875 GF60 covers 5% aluminum alloy-coated steel.
Surface Roughness B IBC 2021 Section 1609.4.2
For wind exposure classification, urban and suburban areas, wooded areas, or other terrain with numerous closely spaced obstructions the size of single-family dwellings or larger.
Nesting (asphalt shingle re-cover) NRCA Roofing Manual: Steep-slope Roof Systems (2025), Asphalt Shingle Roof Systems, Chapter 6—Reroofing, Section 6.5
Application of an additional layer of shingles over an existing layer where the top edge of the new shingles butts against the lower edge of the existing shingles, with no underlayment as part of the re-cover system.
Impermeable synthetic sheet underlayment NRCA Roofing Manual: Steep-slope Roof Systems (2025), Section 3.1—Underlayment Materials (Synthetic Sheets)
A synthetic underlayment with a water vapor transmission rating of less than 0.1 perms; NRCA recommends against specifying it over unvented or inadequately ventilated attics.
Oil canning / tension precision leveling NRCA Roofing Manual: Metal Panel and SPF Roof Systems (2024), Pages 95-96 (Chapter 4, Section 4.4—Oil Canning)
Tension precision leveling stretches coil metal beyond its yield point to give a level surface less prone to oil canning; NRCA suggests specifying tension precision-leveled stock, done after secondary coil operations such as slitting.
Full-cell vacuum-pressure process IBC 2021 Section 1505.6
The impregnation process (per AWPA C1) by which fire-retardant-treated wood shakes and shingles must be treated with chemicals.

Formulas to Know

Roof pitch and its conversion to slopePitch = Total Rise ÷ Total Span (span = horizontal eave-to-eave distance); Slope = 2 × Pitch
Slope from total rise and total run (x-in-12 format)Slope = (Total Rise ÷ Total Run) × 12; e.g., (8 ft ÷ 16 ft) × 12 = 6 in 12; from elevations, rise = peak elev. − bottom chord elev. and run = span ÷ 2
Rise and ridge elevation for a symmetric gableRun = Span ÷ 2; Rise = Run × (pitch ÷ 12); Ridge elevation = top-of-wall elevation + Rise (e.g., 63'÷2 = 31.5'; 31.5 × 8/12 = 21.0'; 12.0' + 21.0' = 33.0')
Sloped rafter line length (no overhang) by PythagorasRafter length = √(Run² + Rise²); e.g., √(28² + 14²) = √980 = 31.30'; √(31.5² + 21²) = √1433.25 = 37.86'
Top chord / roof slope angle from horizontalAngle = arctan(Rise ÷ Run); e.g., arctan(12 ÷ 24) = arctan(0.5) = 26.6°
Actual sloped roof area from plan footprintSloped area = plan-view footprint × slope-conversion factor (multiply, never divide); 6:12 factor 1.118, 3:12 factor 1.031, 2:12 factor 1.014; take off differing-slope sections separately (e.g., porch 24 × 10 = 240 sf × 1.014 = 243 sf)
Actual lengths from run × printed slope factors (rafters, hips, valleys)Common rafter = run × common-rafter factor (10 × 1.118 = 11.2 ft; 10 × 1.054 = 10.54 ft); hip/valley actual length = run × hip-or-valley factor (10 × 1.474 = 14.74 ft, × 4 hips = 59 lin ft); unequal-slope valley = run of low-sloping roof × valley factor (24 × 1.247 = 29.93 lin ft); hip rafter plan length = 1.414 × run (1.414 × 14 = 19.80 ft)
Ridge length of a conventionally framed hip roofRidge = L − [2 × (W ÷ 2)] = L − W; e.g., 40 ft − 20 ft = 20 lin ft
Material quantities with waste allowance3-tab shingles: net squares × 1.05 waste × 3 bundles per square, round up (10.73 × 1.05 × 3 = 33.8 → 34 bundles; 10.24 × 1.05 × 3 = 32.2 → 33 bundles). 15-lb felt: squares × 1.05 ÷ 4 squares per roll, round up (6.50 × 1.05 = 6.82 ÷ 4 = 1.71 → 2 rolls)
Drain sump sizing (membrane and SPF roofs)Sump dimension = drain bowl diameter + 24 in (12" bowl → 36" × 36" minimum; 18" bowl → 42" round sump, sloped 1½:12 for SPF)
Roof live load reduction factors for ordinary pitched roofsR2 = 1.0 for F ≤ 4; R2 = 1.2 − 0.05F for 4 < F < 12 (F = inches of rise per foot; F = 6 → R2 = 0.90); R2 = 0.6 for F ≥ 12. R1 = 1.0 for At ≤ 200 sf; R1 = 1.2 − 0.001At for 200 < At < 600 sf; R1 = 0.6 for At ≥ 600 sf
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