Exam Cheat Sheet · Quick Reference

South Carolina Residential Builder

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
110
Passing score
70%
Exam time
360 min
Administered by
PSI Services Contractor
Format
Reference materials allowed

South Carolina State Portion 110 questions

General Building Construction 74 Q · 67%
General CarpentryConcrete & ReinforcementEstimating and Plan ReadingMasonryRoofingSite Work, Footings and FoundationsFoundation footing design and minimum dimensions by soil bearing capacityConcrete compressive strength requirements by location and weathering exposureFoundation drainage, dampproofing, and waterproofing requirementsSoil types, bearing capacity, and geotechnical evaluationFoundation anchorage of sill plates and anchor bolt requirementsFrost protection and minimum footing depth requirements +2 more
Residential Electrical 12 Q · 11%
Services/Feeders/Branch CircuitsOvercurrent ProtectionGrounding and BondingConductors and CablesRaceways and BoxesLighting and Specialty ApplicationsGFCI and AFCI protection requirements by locationService entrance, sizing, and disconnect requirementsBranch circuit requirements and overcurrent protectionGrounding electrode system and bondingReceptacle outlet placement and spacing requirementsWiring methods and installation requirements +2 more
Residential HVAC 12 Q · 11%
Hangars and SupportsFurnaces and HeatersChimneys, Flues, and VentsCombustion AirDucts, Ventilation and ExhaustFuel Gas and OilPipingEquipment sizing using ACCA Manual J and Manual SCondensate disposal systems and auxiliary drain pansDuct system construction, materials, and installation requirementsReturn air restrictions and prohibited locationsCombustion air requirements for fuel-burning appliances +3 more
Residential Plumbing 12 Q · 11%
General Plumbing and RegulationsPiping/Valves/ControlsFixtures and EquipmentWater SupplyDrain/Waste and Vents/SewersSpecialty ApplicationsDrain, waste, and vent (DWV) system materials and pipe sizingWater supply system design, materials, and pipe sizingPlumbing fixture installation requirements and clearancesInspection and testing of plumbing systemsBackflow prevention and potable water protectionSanitary drainage system design and cleanout requirements +2 more

Key Distinctions

Quantity takeoff estimatevsPre-design / parametric estimate

A quantity takeoff is prepared after design is complete by counting and measuring actual material quantities from finished construction documents, while pre-design estimates are rough approximations made before drawings are finished and parametric estimates use historical cost-per-unit data.

IRC Section R602.3, Table R602.3(1)
Nominal lumber dimensionsvsActual (dressed) dimensions

Board feet are always figured on nominal dimensions (a 2×6 counts as 2 in. × 6 in.), while the actual surfaced/seasoned size is smaller (a 2×4 is about 1½ in. × 3½ in.) and is what codes use for maximum hole-drilling and notching limits.

IRC Section R602.1, R602.3
SlopevsPitch

Slope is a ratio of rise to run (the term best suited to roof framing), while pitch is a ratio of rise to span.

Carpentry and Building Construction, Page 470
Shed (single-slope) roof common raftervsGable roof common rafter

A shed roof common rafter's total run equals the building span minus the width of the top plate on the higher wall and it has two bird's mouths, while a gable common rafter's total run is one-half the span and it has one bird's mouth.

Carpentry and Building Construction, Page 483
Foundation wall projection with masonry veneervsFoundation wall projection in all other conditions

Concrete and masonry foundation walls must extend not less than 4 inches above finished grade where masonry veneer is used, but not less than 6 inches elsewhere.

IRC 2021 Section R404.1.6
Type M mortarvsType N, S, and O mortar

Type M has high compressive strength and durability for heavily loaded or below-grade foundation walls; Type N is general masonry above grade, Type S is for earthquake/high-wind zones, and Type O is low-strength for interior walls.

Carpentry and Building Construction, Section 10.3, Page 279
Type V portland cementvsType II portland cement

Type V is sulfate-resistant cement specifically for high-sulfate soils, solutions, or groundwater, while Type II provides only moderate sulfate resistance.

Contractor's Guide to Quality Concrete Construction (4th ed.), Page 15
Grade SW building brickvsGrade MW / NW building brick

Grade SW (severe weathering) is highly frost-resistant for brick exposed to freezing weather such as foundation courses and retaining walls, while MW is for moderate exposure and NW is for interior backup masonry.

Modern Masonry (9th ed.), Page 116
Common (American) bondvsFlemish, English, and stack bond

Common bond is a running-bond variation with full-length header courses every fifth to seventh course for structural bonding; Flemish alternates headers and stretchers in every course, English uses alternating full header and stretcher courses, and stack bond is pattern only with no overlapping.

Modern Masonry (9th ed.), Pages 129-130
Ridge boardvsCollar tie

The ridge board is the horizontal member connecting the upper ends of the rafters and running the full length of the house, while a collar tie is a horizontal tie connecting opposing rafter pairs to keep them from spreading or bowing inward.

Carpentry and Building Construction, Page 468
Hip and valley raftersvsCommon rafters

Hip and valley rafters must be 2 inches wider in nominal dimension than the common rafters (2×8 hips with 2×6 commons) to give full bearing to jack rafters, and their unit run is 16.97 in. versus 12 in. for a common rafter.

Carpentry and Building Construction, Chapter 18, Page 504
Unit of measure for walls in a unit-cost estimatevsUnit of measure for floors and roofs

Interior partition walls are measured in lineal feet (LF) with the cost per lineal foot covering framing through finish, while floors and roofs are measured in square feet (SF).

Carpentry and Building Construction, Section 2.4, Pages 61-62

Key Terms

Quantity takeoff estimate IRC Section R602.3, Table R602.3(1)
An estimate made from completed construction documents by counting and measuring the actual quantities of materials shown on the plans and specifications.
Plot plan Carpentry and Building Construction, Chapter 9 — Basic Techniques / Using Surveying Instruments / Plot Plan
The part of the house plans showing the location of the building on the lot along with related land elevations; it is the basis for site layout.
Site layout Carpentry and Building Construction, Chapter 9 — Basic Techniques / Purpose of Site Layout
The process of marking the building location from the plot plan onto the land so the house is positioned correctly on the lot per building and zoning codes and site factors such as utilities, views, and privacy.
Batter boards Carpentry and Building Construction, Chapter 9 — Setting Up Batter Boards
Corner layout boards supported by three 2×4 stakes driven at each building corner at least 4 feet beyond the foundation lines to hold building lines clear of excavation.
Overdig Carpentry and Building Construction, Chapter 9 — The Excavation / Overdig
The additional excavation beyond the foundation walls that provides clearance to install and remove concrete forms, lay up block, waterproof exterior surfaces, and install foundation drainage.
Porosity Carpentry and Building Construction, Chapter 9 — The Excavation
The measurement of the ability of water to flow through soil; poorly draining soil may have to be excavated and replaced with better soil.
Bearing capacity Carpentry and Building Construction, Chapter 9 — The Excavation / Soil Testing
A measure of how well the soil can support the weight of a house, and one of the reasons test borings are made before excavation.
Consolidation Carpentry and Building Construction, Section 8.2, Page 227
The process that removes air pockets and forces concrete into all parts of the forms, done with a vibrator, by tamping, spearing with a spade, or tapping the forms with a hammer.
Efflorescence Carpentry and Building Construction, Chapter 8 — Troubleshooting Concrete section
A whitish crystalline deposit on concrete or mortar caused by salts rising to the surface with water or moisture vapor; it is cosmetic and generally does not affect strength or durability.
Shear wall Carpentry and Building Construction, Page 378
A wall designed to resist lateral (sideways) forces, often created by a specified sheathing nail spacing and properly fastened to the framing above and to the sill plate and foundation below.
Schedules (window and door) Carpentry and Building Construction, Section 16.2, Page 440
Charts included in building plans that provide rough-opening sizes and related information for windows and doors, used in layout and estimating.
Differential leveling Carpentry and Building Construction, Chapter 9 — Measuring a Difference in Elevation
Determining the difference in elevation between points remote from each other by using one or more additional intermediate instrument setups.
Camber Contractor's Guide to Quality Concrete Construction (4th ed.), Page 77
A slight upward curvature built into a form or structural member to compensate for deflection, shrinkage, and creep.
Theodolite Carpentry and Building Construction, Chapter 9 — Types of Instruments
A transit that reads horizontal and vertical angles electronically and displays them on an LCD screen, needing no vernier scale; used where extremely accurate measurements are required.
Setting-type joint compound Gypsum Construction Handbook (7th ed.), Chapter 5 — Finishing Drywall Systems, — Setting-Type Joint Compounds System Applications, One-Day Finishing section
A joint compound that hardens chemically rather than by drying; for one-day finishing a compound setting within 1-1/2 to 2 hours lets embedding, fill, and finish coats be applied the same day.
Unit run of a hip rafter Carpentry and Building Construction, Section 18.1, Page 506
16.97 inches (often rounded to 17), the hypotenuse of a right triangle whose two shorter sides are each the 12-inch unit run of a common rafter.

Formulas to Know

Board feet of lumber (nominal dimensions)Board feet per piece = (nominal thickness in. × nominal width in. × length ft) ÷ 12; multiply by number of pieces. Ex.: (2×10×22)÷12 = 36.67 BF × 24 pieces ≈ 880 BF; (2×4×10)÷12 = 6.67 BF × 35 = 233 BF; 2×6×12' = 12 BF × 50 = 600 BF.
Excavation volume in cubic yards (with clearance)Add clearance to each side: (length + 2 sides) × (width + 2 sides) × depth = cubic feet; ÷ 27 = cubic yards. Ex.: 44 × 30 × 7 = 9,240 cf ÷ 27 ≈ 342 cy (equivalently 1,320 sf × 0.259 cy/sf for 7 ft depth ≈ 342 cy).
Stud count for a wall at 16 in. o.c.Studs = (wall length ft ÷ 1.333 ft) + 1, not counting extras for corners/openings. Ex.: (48 ÷ 1.333) + 1 = 37 studs.
Board feet from a per-100-square-feet tableBoard feet = (surface area sf ÷ 100) × table BF per 100 sf. Ex. roof: (2,100 ÷ 100) × 102 BF for 2×6 rafters at 16" o.c. = 2,142 BF (includes rafters, hips/valleys, ridge, collar ties); ceiling plank 2×6 at 16" o.c. = 88 BF per 100 sf (63 BF at 24" o.c.).
Roof sheathing panels with waste allowancePanels = roof area ÷ 32 sf per panel, then add 5% for trim and waste. Ex.: 72.19 × 0.05 = 3.6; 72.19 + 3.6 = 75.79 → 76 sheets.
Crawl-space ventilation net area1 sq ft of net venting per 150 sq ft of crawl-space area. Ex.: 1,200 ÷ 150 = 8 sq ft.
Footing size increase for wide buildingsWhere building width perpendicular to the wall footing exceeds 32 ft, increase footing width 2 in. and footing depth 1 in. for every 4 ft of additional width. Ex.: 36-ft building = +2 in. width, +1 in. depth.
Concrete for a continuous perimeter footingVolume = length × width × depth ÷ 27. Ex.: 200 ft × 2 ft × 1 ft = 400 cf ÷ 27 = 14.8 cy → order 15 cy.
Reading dimensions at ¼" = 1'-0" scaleEach ¼ in. on the drawing = 1 ft actual; actual length = drawing inches ÷ 0.25. Ex.: 3 in. ÷ 0.25 = 12 ft.
3-4-5 method to prove a square cornerUse multiples of 3, 4, 5: measure 9 ft on one line and 12 ft on the adjoining line; the diagonal must be 15 ft for a true 90° corner.
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