Exam Cheat Sheet · Quick Reference
Mississippi Residential Roofer
Mississippi · 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
60
Passing score
70%
Exam time
120 min
Administered by
PSI Services Contractor
Format
Reference materials allowed
Mississippi State Portion 60 questions
Materials
18 Q · 30%
Asphalt shingle types, components, and material standards (ASTM D3462, D3018)Underlayment materials, classifications, and standards (asphalt felt, synthetic, self-adhering polymer-modified bitumen)Roof deck substrates (plywood, OSB, wood planks/boards) and minimum thickness requirementsClay and concrete roof tile types, profiles, physical properties, and material standards (ASTM C1167, C1492)Slate roofing material characteristics, grades, sizes, and standards (ASTM C406)Wood shakes and wood shingles types, grades, and species standards (CSSB, CSA)Metal shingle materials (aluminum, copper, steel, zinc) and protective coatingsFire classification of roof assemblies and coverings (Class A, B, C ratings)
Installation of Roof Coverings
21 Q · 35%
Asphalt shingle types, materials, and installation requirementsUnderlayment types, configurations, and application by roof covering materialRoof deck types, inspection, and preparation for steep-slope systemsFlashing installation requirements including valleys, crickets, and penetrationsClay, concrete, slate, wood shake/shingle, and metal shingle installation methods and minimum slopesFire classification of roof coverings (Class A, B, C) under IBC/IRCWind resistance requirements and testing standards for steep-slope roof coveringsReroofing: re-cover versus tear-off evaluation and code requirements
Roof Drainage
6 Q · 10%
Primary roof drains: placement requirements and sizingSecondary (emergency overflow) drains and scuppers: code requirements and inlet elevation rulesGutters and downspouts: materials, placement, and securementValley drainage: open, closed-cut, and woven valley types and flashing requirementsDrip edge installation at eaves and rakesCrickets and saddles: requirements for chimneys and wide penetrationsPonding water prevention on low-slope roofsMaintenance of drainage paths: debris removal and leak diagnosis at valleys and gutters
Rooftop Structures
9 Q · 15%
Roof deck types and material requirements (plywood, OSB, wood planks) by roof covering typeRoof deck inspection and preparation standards prior to installationRooftop accessories installation (equipment curbs, skylights, roof vents, snow guards, photovoltaic supports)Equipment curb flashing requirements (apron, step, cricket/backer, counterflashing, minimum heights)Chimney, dormer and skylight flashing details (crickets/saddles, step and counterflashing, minimum metal thickness)Attic ventilation requirements: net free area ratios, intake/exhaust balance, ridge and soffit vents (IRC R806)Roof framing, rafter span and design loads for residential roofs (dead, live, snow, wind)Wind uplift resistance requirements for roof coverings and assemblies (ASCE 7, IBC Chapter 15)Fire classification of roof assemblies (Class A, B, C) and applicable construction types
Safety
6 Q · 10%
Fall protection requirements for roofing work (low-slope and steep roofs)Personal fall arrest system components, criteria, and inspectionGuardrail system specifications and performance requirementsWarning line systems and safety monitoring systems for roofingLadder safety requirements, types, and useScaffold safety requirements and fall protection on scaffoldsPersonal protective equipment selection, use, and maintenanceFire protection, prevention, and flammable liquid storage on construction sites
Key Distinctions
Wood Shingles (naturally durable wood)vsWood Shakes (naturally durable wood)
Wood shingles may be Grade 1, 2, or 3 per CSSB rules, while wood shakes require a minimum of Grade 1.
IBC 2021, Table 1507.8.5Class A Roof AssemblyvsClass B Roof Assembly
Class A is effective against severe fire-test exposure, while Class B is effective against only moderate fire-test exposure.
IBC 2021, Section 1505.2Class B Roof AssemblyvsClass C Roof Assembly
Class B is effective against moderate fire-test exposure, while Class C is effective against only light fire-test exposure.
IBC 2021, Section 1505.3Positive Method (roof measurement)vsNegative Method (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 non-roof areas; both yield the same result.
Roofing Construction and Estimating, Chapter 1, Pages 7-8Fiberglass Asphalt ShinglesvsOrganic Asphalt Shingles
Fiberglass shingles use a fiberglass mat as the base, while organic shingles use a cellulose-fiber base mat.
Roofing Construction and Estimating, Chapter 4—Asphalt ShinglesASTM D3161 Wind ResistancevsASTM D7158 Wind Resistance
ASTM D3161 classifies shingles at fan-induced wind velocities (Class A = 60 mph, D = 90 mph, F = 110 mph), while ASTM D7158 classifies by basic wind speed zones (Class D up to 90 mph, G up to 120 mph, H up to 150 mph).
NRCA Roofing Manual: Steep Slope Roof Systems, Section 4.1—Wind Resistance (ASTM D3161)Clay Roof Tile (ASTM C1167)vsConcrete Roof Tile (ASTM C1492)
Clay roof tile must comply with ASTM C1167, while concrete roof tile must comply with ASTM C1492.
IBC 2021, Section 1507.3.4Slate Shingles (deck requirement)vsWood Shingles/Shakes (deck requirement)
Slate shingles must be fastened to a solidly sheathed deck and do not permit spaced sheathing, while wood shingles and shakes may use spaced sheathing.
IBC 2021, Section 1507.7.1Single-layer Underlayment (clay/concrete tile)vsSelf-adhering or Double-layer Underlayment (clay/concrete tile)
A single layer of mechanically attached underlayment requires a minimum roof slope of 4:12, while self-adhering or double-layer configurations permit a minimum slope of 2½:12 per IBC/IRC.
NRCA Roofing Manual: Steep-slope Roof Systems, Clay and Concrete Tile Roof Systems, Chapter 1—Roof Assembly Configurations, Single-layer Underlayment Mechanically AttachedNail Penetration — Plywood Deck (<¾ inch)vsNail Penetration — Wood Plank/Board Deck
For plywood decks less than ¾ inch thick, nails must extend at least ⅛ inch through the underside; for wood plank or board decks, nails must penetrate at least ¾ inch into the deck.
NRCA Roofing Manual: Steep Slope Roof Systems, Section 4.2—Asphalt Shingle Roof System Design and Installation (Fasteners)Cricket (chimney flashing)vsBacker Flashing (chimney flashing)
NRCA recommends a cricket when a chimney or curbed penetration is more than 24 inches wide, while backer flashing is generally used for penetrations 24 inches wide or less.
NRCA Roofing Manual: Steep Slope Roof Systems, Asphalt Shingle Roof Systems — Chapter 72-inch Tongue-and-Groove Deckingvs3- and 4-inch Tongue-and-Groove Decking
Two-inch sawn tongue-and-groove decking requires a single tongue-and-groove pattern, while three-inch and four-inch decking must be machined with a double tongue-and-groove pattern per IBC Section 2304.9.5.1.
2021 IBC, Section 2304.9.5.1Key Terms
Class A Roof Assembly IBC 2021, Section 1505.2
Per IBC 2021 Section 1505.2, a roof assembly tested per ASTM E108 or UL 790 that is effective against severe fire-test exposure.
Class B Roof Assembly IBC 2021, Section 1505.3
Per IBC 2021 Section 1505.3, a roof assembly effective against moderate fire-test exposure.
Class C Roof Assembly IBC 2021, Section 1505.4
Per IBC 2021 Section 1505.4, a roof assembly effective against light fire-test exposure.
Fire-Retardant-Treated Wood (roof coverings) IBC 2021, Section 1505.6
Per IBC 2021 Section 1505.6, wood shakes and shingles treated by impregnation with chemicals using the full-cell vacuum-pressure process in accordance with AWPA C1.
Solidly Sheathed Deck (slate requirement) IBC 2021, Section 1507.7.1
Per IBC 2021 Section 1507.7.1, the required deck type for slate shingles — spaced sheathing is not permitted for slate installations.
Minimum Copper Weight — Class A Exception IBC 2021, Section 1505.2, Exception 3
Per IBC 2021 Section 1505.2 Exception 3, copper sheets weighing at least 16 ounces per square foot installed over a combustible deck qualify as a Class A roof assembly.
Slate Underlayment — Class A Exception IBC 2021, Section 1505.2, Exception 4
Per IBC 2021 Section 1505.2 Exception 4, slate installed over ASTM D226 Type II underlayment on a combustible deck qualifies as a Class A roof assembly.
Galvanized Steel Corrosion Resistance (metal roofing) IBC 2021, Table 1507.4.3(2)
Per IBC 2021 Table 1507.4.3(2), galvanized steel used in metal roof coverings must meet a minimum of ASTM A653 G90 zinc-coated.
Minimum Zinc Thickness (metal roofing) IBC 2021, Table 1507.4.3(1)
Per IBC 2021 Table 1507.4.3(1), zinc metal roof covering requires a minimum thickness of 0.027 inch.
ASTM D7158 Wind Classification NRCA Roofing Manual: Steep Slope Roof Systems, Section 4.1—Wind Resistance (ASTM D7158)
A standard classifying asphalt shingles for wind resistance: Class D passes up to 90 mph basic wind speed, Class G up to 120 mph, and Class H up to 150 mph.
UL 2218 Impact Resistance Class 4 NRCA Roofing Manual: Steep Slope Roof Systems, Section 4.1—Impact Resistance Rating
The highest impact-resistance classification under UL 2218 for prepared roof coverings, representing the greatest measured level of impact resistance.
Impermeable Synthetic Underlayment NRCA Roofing Manual: Steep Slope Roof Systems, Section 3.1—Underlayment Materials (Synthetic Sheets)
Per NRCA, a synthetic sheet underlayment with a water vapor transmission rating of less than 0.1 perms, which NRCA recommends against using over unvented or inadequately ventilated attics.
ASTM D1970 NRCA Roofing Manual: Steep Slope Roof Systems, Section 3.1—Underlayment Materials
Standard Specification for Self-Adhering Polymer Modified Bituminous Sheet Materials Used as Steep Roofing 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, Section 3.1—Underlayment Materials (Synthetic Sheets)
Standard Specification for Mechanically Attached Polymeric Roof Underlayments Used in Steep Slope Roofing, applicable to synthetic sheet underlayments and referenced in IBC and IRC 2024 editions.
Cricket (roof) NRCA Roofing Manual: Steep Slope Roof Systems, Asphalt Shingle Roof Systems — Chapter 7
A peaked drainage saddle installed on the upslope side of a chimney or curbed penetration wider than 24 inches to divert water around the obstruction.
ASTM C1167 Grade 1 (clay tile) NRCA Roofing Manual: Steep Slope Roof Systems, Section 4.1—Clay and Concrete Tile Materials (Standards)
The highest grade of clay roof tile under ASTM C1167, providing resistance to severe frost action.
Formulas to Know
Roof Area (rectangle)
Length × Width = AreaPositive Method — Irregular Roof Area
Area = Sum of all individual rectangle areasNegative Method — Irregular Roof Area
Area = Large enclosing rectangle area − Non-roof areasSquares of Roofing Needed
Number of squares = Total roof area (sq ft) ÷ 100Roof Slope Ratio
Slope = Rise (inches) : Run (12 inches), e.g., 4:12Shingle Exposure
Exposure = Shingle length − Headlap − Top selvage (if applicable)