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 CSSB Grade 1, 2, or 3, while wood shakes require a minimum of Grade 1 (taper sawn shakes allow Grade 1 or 2).
IBC 2021 Table 1507.8.5Class A roof assemblyvsClass B roof assembly
Class A assemblies are effective against severe fire-test exposure; Class B assemblies are effective against moderate fire-test exposure (Class C is light exposure).
IBC 2021 Section 1505.2ASTM D3161 wind-resistance testvsASTM D7158 wind-resistance test
ASTM D3161 is a fan-induced wind test (Class A passes at 60 mph, Class D at 90 mph, Class F at 110 mph), while ASTM D7158 is a test plus complex calculation based on ASCE 7-22 building environment factors producing basic-wind-speed classes (D up to 90 mph, G up to 120 mph, H up to 150 mph).
NRCA Roofing Manual: Steep-slope Roof Systems (2025), Section 4.1—Wind Resistance (ASTM D3161)Positive method of roof measurementvsNegative method of roof measurement
The positive method divides an irregular roof into rectangles and adds their areas; the negative method extends roof lines into one large rectangle and subtracts the non-roof areas — both give identical results.
Roofing Construction and Estimating, Chapter 1, Pages 7-8Nailing asphalt shingles to wood plank/board decksvsNailing asphalt shingles to plywood decks less than ¾ inch thick
Nails must penetrate at least ¾ inch into wood plank or board decks, but must extend a minimum of ⅛ inch through the underside of plywood/wood panel decks less than ¾ inch thick.
NRCA Roofing Manual: Steep-slope Roof Systems (2025), Section 4.2—Asphalt Shingle Roof System Design and Installation (Fasteners)Fiberglass asphalt shinglesvsOrganic asphalt shingles
Fiberglass shingles use a fiberglass base mat saturated and covered with flexible asphalt and surfaced with mineral granules; organic shingles use a cellulose-fiber base mat.
Roofing Construction and Estimating, Chapter 4—Asphalt ShinglesClay roof tilevsConcrete roof tile
Clay roof tile must comply with ASTM C1167, while concrete roof tile must comply with ASTM C1492.
IBC 2021 Section 1507.3.4Spaced (skip) sheathing for wood shakesvsSpaced (skip) sheathing for wood shingles
Shakes are normally laid over 1 × 6 boards (spacing equal to the shake weather exposure), while wood shingles typically use 1 × 4 boards.
Roofing Construction and Estimating, Page 30Copper 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)Plywood sheathing over rafters at 16 in. o.c.vsPlywood sheathing over rafters at 24 in. o.c.
NRCA recommends minimum four-ply nominal ⅝-inch (actual 19/32-in.) plywood at 16-inch rafter spacing and nominal ¾-inch (actual 23/32-in.) plywood at 24-inch rafter spacing for asphalt shingle roofs.
NRCA Roofing Manual: Steep-slope Roof Systems (2025), Section 2.1—Wood PanelsCricket at a chimney/curbvsBacker flashing at a chimney/curb
NRCA recommends a cricket on the upslope side 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 7Tile roof with single-layer mechanically attached underlaymentvsTile roof with self-adhering or double-layer underlayment
For new clay/concrete tile roofs, single-layer mechanically attached underlayment requires a minimum 4:12 slope per IBC/IRC (NRCA also recommends 4:12), while self-adhering or double-layer configurations permit a minimum 2½:12 slope.
NRCA Roofing Manual: Steep-slope Roof Systems (2025), Clay and Concrete Tile Roof Systems, Chapter 1—Roof Assembly Configurations, Single-layer Underlayment Mechanically AttachedKey Terms
Class A roof assembly IBC 2021 Section 1505.2
A roof assembly effective against severe fire-test exposure; examples include 16 oz./sq. ft. copper sheet over a combustible deck and slate installed over ASTM D226 Type II underlayment over a combustible deck.
Class B roof assembly IBC 2021 Section 1505.3
A roof assembly effective against moderate fire-test exposure.
Class C roof assembly IBC 2021 Section 1505.4
A roof assembly effective against light fire-test exposure.
ASTM E108 / UL 790 IBC 2021 Section 1505.1
The test standards used for Class A, B, and C roof assemblies and roof coverings required to be listed (ASTM D2898 applies additionally to fire-retardant-treated wood coverings only).
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-roofing underlayment for ice-dam protection, covering 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 IV (#26) is equivalent to ASTM D226 Type II (No. 30 felt) and Type II (#13) is equivalent to ASTM D226 Type I (No. 15 felt).
ASTM C406 IBC 2021 Section 1507.7.5
The material standard that slate shingles must comply with.
ASTM C1167 tile grades NRCA Roofing Manual: Steep-slope Roof Systems (2025), Section 4.1—Clay and Concrete Tile Materials (Standards)
Clay roof tile standard classifying three grades by frost resistance: Grade 1 (severe frost action), Grade 2 (moderate frost action), Grade 3 (negligible resistance).
ASTM A653 G90 IBC 2021 Table 1507.4.3(2)
The minimum corrosion-resistance standard (zinc-coated) for 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.
UL 2218 NRCA Roofing Manual: Steep-slope Roof Systems (2025), Section 4.1—Impact Resistance Rating
Impact Resistance of Prepared Roof Coverings, with Classes 1 through 4, where Class 1 is the least and Class 4 the greatest measured impact resistance.
Full-cell vacuum-pressure process IBC 2021 Section 1505.6
The impregnation process, in accordance with AWPA C1, required for chemically treating fire-retardant-treated wood shakes and shingles.
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 shingle layer over an existing layer where the top edge of the new shingles butts against the lower edge of the existing shingles; underlayment is not part of the re-cover system.
Surface Roughness B IBC 2021 Section 1609.4.2
Wind exposure surface roughness category for urban and suburban areas, wooded areas, or terrain with numerous closely spaced obstructions the size of single-family dwellings or larger (C is open terrain with scattered obstructions under 30 ft; D is flat, unobstructed areas and water surfaces).
Formulas to Know
Roof slope and pitch
Slope = (Total Rise ÷ Total Run) × 12 (expressed as inches of rise per 12 in. of run); Pitch = Total Rise ÷ Total Span; Slope = 2 × PitchRidge rise above the eave/wall line (symmetric gable or hip)
Run = half the span (width); Rise = Run × (slope rise ÷ 12); Ridge elevation = top-of-wall elevation + Rise (e.g., 31.50 × 8/12 = 21.00 ft; 12.00 + 21.00 = 33.00 ft)Sloped rafter length by Pythagorean theorem
Rafter length = √(Run² + Rise²), with Run = half the span and Rise = ridge elevation − wall elevation (e.g., √(31.50² + 21.00²) = 37.86 ft)Actual common rafter length using printed slope factor
Rafter length = Run (half the width) × common-rafter factor (e.g., 10 ft × 1.118 = 11.18 ft; 12 ft × 1.250 = 15.00 ft)Slope angle of the top chord from horizontal
Angle = arctan(Rise ÷ Run) (e.g., arctan(12 ÷ 24) = 26.6°)Net (actual) roof area in squares
Net roof area = roof plan area × roof-slope factor; squares = net area ÷ 100 (e.g., (36 × 24) × 1.414 = 1,222 sq ft = 12.22 squares)Ridge length of a conventionally framed hip roof
Ridge = L − [2 × (W/2)] = L − W (e.g., 40 − 20 = 20 lin ft; 34 − 24 = 10 lin ft)Hip rafter length
Plan length of hip = 1.414 × run (√2, for the 45° plan angle); Actual hip length = run × hip-or-valley factor (e.g., 10 × 1.474 = 14.74 ft per hip)Valley length where roofs of unequal slope intersect
Actual valley length = run of the low-sloping roof × valley length factor (e.g., 24 ft × 1.247 = 29.93 lin ft)Roof live load reduction factors (ordinary pitched roofs)
R1 = 1.0 for At ≤ 200 sq ft; R1 = 1.2 − 0.001At for 200 < At < 600; R1 = 0.6 for At ≥ 600 sq ft. R2 = 1.0 for F ≤ 4; R2 = 1.2 − 0.05F for 4 < F < 12 (F = inches of rise per foot); R2 = 0.6 for F ≥ 12