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newSchoolWorks.com › VoTechWorks › Building & Construction › Carpentry › Capstone Project: Integrated Carpentry Build › Lesson 2
BLD-CARP03-09 · Lesson 2 · 72 clock hours · lab

Rough Framing, Sheathing, and Roofing Phase

Objective. Students construct the floor platform, wall framing, roof framing, and sheathing of their approved capstone structure, meeting dimensional tolerances and structural layout requirements consistent with NCCER Carpentry Level 2 and Level 3 performance tasks.

Rough Framing, Sheathing, and Roofing Phase

This lab phase is the heart of your capstone build. You will construct the floor platform, wall framing, roof framing, and sheathing that give your structure its shape, strength, and dimensional accuracy. Work carefully and systematically—errors made in the floor layout compound through every layer above it.

Floor Platform: Laying Out and Building Square

Begin by positioning your sill plate or rim joist according to your approved plan. Before any fastening, verify that the platform is square using one of two methods:

3-4-5 method: Measure 3 feet along one side from a corner, 4 feet along the adjacent side from the same corner, and check that the diagonal between those two marks is exactly 5 feet. If it is, that corner is 90 degrees. Repeat at every corner.

Diagonal measurement: Measure corner to corner in both directions across the full platform. If both diagonals are equal, the platform is square. Your instructor will check both diagonals before you install subfloor sheathing—they must be within 1/8 inch of each other.

Install floor joists at the spacing shown on your plan, using joist hangers where required. Crown every joist before placing it: sight down the length and orient any bow upward so live load pushes it flat over time. Install blocking or bridging where the plan calls for it.

Subfloor sheathing (OSB or plywood) runs perpendicular to the joists. Stagger end joints by at least one joist bay. Fasten with the spacing specified on your plan and the sheathing manufacturer's edge-and-field schedule. Do not skip fasteners—the nailing pattern is a structural requirement, not a suggestion.

Wall Framing

You must frame at least two walls, and at least one must contain a rough opening for a door or window. A rough opening is sized larger than the finished unit to allow for shimming and the king-stud, trimmer-stud, and header assembly.

For each wall, snap a chalk line on the subfloor for the plate location. Cut plates to length, lay them face to face, and mark stud layout together so crown marks align. Standard stud spacing is 16 inches or 24 inches on center as shown in your plan. Mark with an X on the layout side so every stud goes in the right place.

Assemble the wall flat on the deck: bottom plate, top plate, full-length studs, king studs, trimmer studs, header, cripple studs above and below the opening as required. Toenail or use metal connectors as specified. When the wall is built, check it for square by measuring diagonals before raising.

Raise and brace each wall immediately. Temporary braces run from the top plate to the floor deck at a diagonal—do not remove them until the walls are plumbed, lined, and sheathed, and adjacent walls or the roof system provides permanent lateral support.

Sheathe walls with OSB or plywood per your plan before moving to the roof. Sheathing at corners provides critical shear resistance. Nail edges at the spacing shown on your plan; field nailing typically differs from edge nailing—know which is which.

Roof Framing

You will install either common rafters or pre-cut trusses. If using common rafters, your approved plan provides the unit rise, run, and rafter length. Verify pitch with your speed square before cutting a pattern rafter; test-fit it, then use it to mark all others. Bird's-mouth cuts must be consistent so every rafter bears the same way on the wall plate.

If using trusses, handle them carefully—a truss is engineered as a complete system and must not be cut or notched. Set trusses plumb, space them to the plan, and brace them laterally before releasing the crane or lift.

Install roof sheathing (OSB or plywood) starting at the eave and working toward the ridge. Stagger joints. Use the fastener schedule from your plan.

Fall Protection: A Non-Negotiable Safety Gate

Any work at or above 6 feet off a lower level requires a properly fitted fall-protection harness and lanyard attached to an adequate anchor point. This is not optional. If you are observed working at height without fall protection, the build stops immediately. You will receive a documented safety counseling before work resumes, and your supervisor or instructor must sign off. No credential is worth a fall. Inspect your harness before every use—check webbing for cuts, buckles for function, and the lanyard for damage.

Additional PPE required throughout this phase: safety glasses whenever cutting or nailing, hard hat when overhead work or lifting is occurring, hearing protection when operating pneumatic nailers or power saws, and work gloves when handling lumber and sheathing edges.

Daily Log

At the end of each work session, record in your log: what you completed, measurements you verified, problems you encountered, and how you resolved them. Attach or reference your progress photos. This log is part of your capstone assessment and reflects professional work habits valued by every employer in the trade.

Walk-Through Checkpoint

Before any finish work begins, you and your instructor conduct a structured walk-through using the NCCER Carpentry Level 2 and Level 3 performance-profile checklist. Every structural item must score Satisfactory. Any item scored Unsatisfactory is corrected by you before the next phase starts. The goal is quality work, not speed—correct it now so the rest of the build is solid.

Key terms8

Rough openingA framed opening in a wall that is sized larger than the finished door or window unit to allow for the king-stud, trimmer-stud, and header assembly plus shimming.
3-4-5 methodA technique for checking a corner for square by measuring 3 feet along one side, 4 feet along the adjacent side, and confirming the diagonal between those points is exactly 5 feet.
CrownThe slight lengthwise bow in a piece of lumber; framers orient the crown upward so that load pushes the member toward flat over time.
Bird's mouthA notch cut near the lower end of a common rafter consisting of a seat cut and a plumb cut, allowing the rafter to bear squarely on the wall plate.
On center (OC)A measurement method for framing layout in which the distance is taken from the center of one member to the center of the next; common spacings are 16 and 24 inches OC.
Shear panelA wall section covered with structural sheathing (OSB or plywood) fastened to a prescribed nailing schedule that resists lateral (racking) forces in the wall plane.
Trimmer studA full-length or shortened stud that runs alongside a king stud and supports the end of a header at a rough opening; also called a jack stud.
Unit rise and unit runComponents of roof pitch expressed as rise in inches per 12 inches of horizontal run; used with a framing square or speed square to lay out rafter cuts.

Worked examples4

1. Your floor platform measures 10 feet by 12 feet. You measure one diagonal and get 180 inches. What should the other diagonal measure if the platform is square, and what is the maximum allowable difference between the two diagonals?
  1. Calculate the true diagonal of a 10 ft × 12 ft rectangle using the Pythagorean theorem: diagonal = √(10² + 12²) = √(100 + 144) = √244 ≈ 15.620 ft.
  2. Convert to inches: 15.620 ft × 12 = 187.4 inches (approximately).
  3. The measured diagonal is 180 inches, which differs from the calculated value—this indicates the platform is not the correct size or is racked. Both diagonals of the actual platform must be compared to each other.
  4. Per the course standard, the two diagonals must be within 1/8 inch (0.125 inch) of each other. If one diagonal is 180 inches, the other must measure between 179 and 7/8 inches and 180 and 1/8 inches to pass.
Answer: The second diagonal must be within 1/8 inch of the first diagonal. Maximum allowable difference between the two diagonals is 1/8 inch (0.125 inch).
2. You are laying out studs on a 14-foot wall at 16 inches on center. Starting from the left end, where is the center of the first, second, and third stud (using standard layout that accounts for sheathing panel edges)?
  1. Standard framing layout begins the first stud center at 15-1/4 inches from the outside face of the corner stud (or end of plate), so that the edge of a 4-foot (48-inch) sheathing panel lands on the center of a stud. However, the simplified method used in many training programs places the first stud center at 16 inches from the end of the plate.
  2. Using the common training-program layout: First stud center = 16 inches from end.
  3. Second stud center = 16 + 16 = 32 inches from end.
  4. Third stud center = 32 + 16 = 48 inches from end.
  5. Mark each location with an X on the layout side of the plate so the stud body falls in the correct direction.
Answer: First stud center at 16 inches, second at 32 inches, third at 48 inches from the end of the plate (each 16 inches OC).
3. Using the 3-4-5 method, you measure 3 feet along one wall plate from a corner and 4 feet along the perpendicular plate from the same corner. Your diagonal measures 5 feet 1 inch. Is the corner square, and which direction do you adjust?
  1. A true 3-4-5 right triangle has a hypotenuse of exactly 5 feet (60 inches). Your diagonal is 5 feet 1 inch (61 inches).
  2. The diagonal is too long by 1 inch, which means the angle at that corner is greater than 90 degrees—the corner is open (obtuse).
  3. To square the corner, push the two plates closer together at their far ends (reduce the angle) until the diagonal measures exactly 5 feet (60 inches).
  4. Re-measure after adjustment and confirm before fastening.
Answer: The corner is not square. The angle is slightly greater than 90 degrees. Push the far ends of the two plates toward each other until the 3-4-5 diagonal measures exactly 60 inches.
4. A roof has a pitch of 6-in-12. Using a speed square, at what angle marking do you set the square to mark a plumb cut on a rafter?
  1. Pitch of 6-in-12 means the roof rises 6 inches for every 12 inches of horizontal run.
  2. On a speed square, the degree scale for common rafters is read directly. A 6-in-12 pitch corresponds to approximately 26.6 degrees.
  3. Set the pivot of the speed square on the edge of the rafter and rotate until the 26.6-degree mark (commonly rounded to 27 on many speed squares) aligns with the edge; scribe along the vertical (plumb) face of the square.
  4. Verify by checking: arctan(6/12) = arctan(0.5) ≈ 26.6 degrees.
Answer: Set the speed square to approximately 26.6 degrees (often marked as 27° on the common-rafter scale) to mark a plumb cut for a 6-in-12 pitch roof.

The math in this lesson1

Learners compute the 10×12 platform diagonal, 16 in stud centers, a 3-4-5 check, and the 6-in-12 plumb-cut setting.
G-SRT.8
Brush up in the math halls at newSchoolWorks.com:
In class: Students lay out and cut floor or deck framing members (sill plate or rim joist, floor joists or skids) following their approved plans, checking for square using the 3-4-5 method or diagonal measurement, then install subfloor or deck sheathing with appropriate fastener spacing—instructor spot-checks diagonals (must be within 1/8 inch of equal) and fastener pattern before framing proceeds. · Students frame at least two walls (one with a rough opening for a door or window), raise, brace, and sheathe them, then install roof framing (common rafters or pre-cut trusses) and roof sheathing, applying appropriate PPE including fall protection equipment whenever working at or above 6 feet; each student records daily progress photos and a brief written log entry describing work completed, problems encountered, and solutions applied. · At the end of the rough phase, instructor and student conduct a structured walk-through using the NCCER Carpentry Level 2/3 performance-profile checklist, measuring stud spacing, checking header sizing against the plan, verifying rafter layout, and confirming sheathing nailing pattern—any item scored 'unsatisfactory' is corrected by the student before the finish phase begins.
Materials: Framing lumber (dimensional lumber per approved takeoff), OSB or plywood sheathing, joist hangers and structural fasteners, circular saw, miter saw, framing nailer, hand nails, hammer, framing square, speed square, tape measures, chalk line, level, fall-protection harness and lanyard (when working at height), safety glasses, hard hat, hearing protection, work gloves, NCCER Carpentry Level 2 and Level 3 modules (reference), daily log notebook or digital log template
Check: Instructor walk-through using NCCER-aligned performance checklist: wall diagonal must be within 1/8 inch, stud spacing within 1/4 inch of plan, roof pitch verified with speed square, sheathing fastener spacing matches plan. Student must score 'Satisfactory' on every structural item to advance. Fall-protection use during elevated work is a binary safety gate—any unprotected work at or above 6 feet stops the build and triggers a documented safety counseling.

Practice check8

Answer each question, then check it. Nothing is recorded; this is your own practice.

NCCER Carpentry Level 2 – Floor Systems
1. When checking a rectangular floor platform for square by measuring diagonals, what is the maximum allowable difference between the two diagonal measurements before proceeding with sheathing?
NCCER Carpentry Level 2 – Floor Systems
2. A framer crowns a floor joist before placing it in the bay. What does 'crowning' mean and why is it done?
NCCER Carpentry Level 2 – Wall and Ceiling Framing
3. You are framing a rough opening for a window. Which combination of members directly supports the ends of the header?
OSHA 10 – Fall Protection
4. According to OSHA Outreach Program guidelines, at what height above a lower level does a construction worker performing carpentry work require fall protection?
NCCER Carpentry Level 2 – Wall and Ceiling Framing
5. Before raising a framed wall section, a carpenter measures its diagonals and finds them unequal. What is the correct action?
NCCER Carpentry Level 2 – Wall and Ceiling Framing
6. What is the primary structural purpose of wall sheathing installed at building corners?
NCCER Carpentry Level 3 – Roof Framing
7. A pre-engineered roof truss arrives on site slightly bowed. A worker proposes cutting a bottom chord to make it fit more easily. Why is this unacceptable?
NCCER Carpentry Level 2/3 – Performance Assessment
8. During the capstone walk-through, the instructor marks a stud-spacing item as 'Unsatisfactory' on the NCCER performance-profile checklist. What must happen before the finish phase of the build begins?
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