Frame a Simple Gable Roof with Rafters

A. Finished-Project Specification

Scope: one completed common-rafter roof frame covering the full approved roof plan area, including the ridge board, all common rafter pairs at the specified spacing, gable-end framing, and all ties, clips, straps, blocking, and outlookers required by the approved roof plan.

B. Required Documentation Schedule

Document	Source	Confirmation Required
Approved roof plan	Design professional / plan set	Current revision on site; states span, run, pitch, ridge height, overhang, rafter size, spacing
Rafter and tie connector schedule	Design professional / manufacturer	Matches specified fasteners, straps, and clips
Prescriptive rafter table or engineered rafter design	Adopted code / qualified designer	Confirms rafter size and spacing for the given span, pitch, and load
Fall-protection and temporary-bracing plan	Project safety plan	Current and applicable to wall-top and roof-height work
Inspection approvals	Authority having jurisdiction	Ceiling-joist/rafter-tie framing inspection confirmed complete before roof loads are applied

C. Component Schedule

Component	Quantity	Material	Finished Size	Preparation
Common rafters	Per approved plan spacing and roof length	Species/grade per approved plan	Length per calculated run and pitch; size per plan	Ridge plumb cut, birdsmouth seat and heel cut, tail cut, matched to verified pattern
Ridge board	1 per roof run, spliced only over specified supports	Species/grade per approved plan	Length and depth per approved plan	Cut square to length; splice location and method per plan
Rafter ties / collar ties	Per approved plan spacing	Per approved plan	Per approved plan	Cut and fastened per specified connection detail
Gable-end studs and framing	Per approved plan	Per approved plan	Per approved plan geometry	Cut to match roof pitch; installed per plan spacing
Outlookers / blocking	Per approved plan	Per approved plan	Per approved plan	Cut and installed at gable overhang per plan detail

D. Material Takeoff

• Rafter stock: quantity, size, and grade per the approved roof plan and calculated rafter count, plus the plan's waste allowance.
• Ridge-board stock: length and depth per the approved plan; splice material where a single length does not span the full ridge run.
• Tie and strap material: type and quantity per the approved connector schedule.
• Temporary bracing stock: sufficient posts, braces, and fasteners to support the ridge and first rafter pairs until permanent connections are complete.

E. Fastener and Hardware Schedule

Joint	Fastener / Hardware	Installation Requirement
Rafter to ridge board	Per approved connector schedule	Toe-fastened or clipped per plan; full contact at ridge plumb cut required before fastening
Rafter to wall plate (birdsmouth)	Per approved connector schedule	Hurricane clip, strap, or toe-fastener per plan; full seat-cut bearing required
Rafter tie / collar tie to rafter	Per approved connector schedule	Fastened at the specified height and spacing to complete the thrust-resistance system
Ridge splice	Per approved connector schedule	Located only over a specified support; do not splice at midspan without plan approval
Gable framing and outlookers	Per approved connector schedule	Fastened per plan detail without altering required roof plane or overhang

F. Acceptance Standards

Check	Standard
Ridge height and plumb	Matches the approved plan elevation and remains plumb through the setting sequence
Rafter spacing	Matches the approved plan spacing at every layout point along the wall plate and ridge
Birdsmouth bearing and depth	Full seat contact on the wall plate; depth does not exceed the approved plan limit
Roof plane and symmetry	Both roof planes align with the string-line check within the approved plan tolerance
Overhang	Matches the approved plan dimension at every rafter tail
Connection completeness	Every rafter, ridge, tie, and gable connection matches the approved connector schedule

G. Reference Layout and Rafter Calculation (Steps 1–7)

1. Review the approved roof plan, span, run, pitch, ridge height, overhang, rafter size, spacing, ties, ceiling framing, connectors, and temporary-bracing plan. Record every value on the Roof Framing Data Record before layout begins.
2. Confirm that the selected structure is designed for site-built rafters and is not the truss structure used in Chapter 15. Verify this against the approved plan's structure identification before proceeding.
3. Verify wall dimensions, wall-top alignment, ceiling-joist or rafter-tie installation, and bearing readiness. Confirm Project 13 has passed its required inspection.
4. Establish the roof centerline, ridge position, rafter-layout reference, and eave lines. Strike the roof centerline on the ceiling framing and mark the eave line on both wall plates from the approved overhang dimension.
5. Obtain or calculate the common-rafter run and length using the approved method and supplied project data. Use the run, pitch, and rafter-length method specified by the project; do not estimate the length from an assumed roof plane.
6. Determine plumb-cut, birdsmouth, tail, and ridge-shortening requirements from the controlled design. Record the ridge-shortening allowance for the ridge-board thickness before laying out the pattern rafter.
7. Lay out one pattern rafter on straight stock using a framing square or approved calculator method. Select stock free of defects in the birdsmouth and plumb-cut zones.

H. Pattern Rafter Layout, Cutting, and Verification (Steps 8–12)

1. Mark the ridge plumb cut, birdsmouth seat cut, heel location, and tail cut from defined references. Measure each cut line from the calculated rafter length and the approved overhang dimension.
2. Verify that the birdsmouth does not exceed the approved depth. Compare the marked seat- and heel-cut depth against the plan's stated limit before cutting.
3. Cut the pattern rafter and test-fit it at both roof sides. Support the pattern rafter at its ridge and wall-bearing locations without permanent fastening.
4. Check ridge height, wall bearing, overhang, plumb cuts, and symmetry. Confirm the pattern matches the approved plan at both test locations before proceeding.
5. Correct the pattern before using it to mark additional rafters. Re-cut or replace the pattern rafter if any check in Step 11 fails, and re-verify before duplication.

I. Duplicating Rafters and Setting the Ridge (Steps 13–16)

1. Mark and cut matching rafters with consistent orientation and labels. Trace each rafter from the verified pattern using the same reference edge, and label each rafter with its plan location.
2. Prepare the ridge board to the required length and support it at the calculated elevation. Install temporary ridge posts or bracing sized for the ridge board's weight and the roof span.
3. Install the first opposing rafter pair and secure it temporarily. Seat each rafter fully at its birdsmouth and against the ridge board before installing temporary restraint.
4. Check ridge plumb, pair alignment, bearing, and roof pitch. Verify the first pair against the approved plan values before continuing.

J. Setting Remaining Rafters and Installing Restraint (Steps 17–20)

1. Install an opposing end pair and brace the ridge line. Add bracing sufficient to hold the ridge line straight through the remainder of the setting sequence.
2. Set intermediate rafter pairs at the approved spacing. Confirm each pair's layout location on the wall plate and ridge before fastening.
3. Install ties, clips, straps, blocking, outlookers, gable framing, and other specified restraint. Complete each connection per the Fastener and Hardware Schedule as each rafter pair is set.
4. Maintain fall protection, controlled access, and material restraint throughout roof work. Verify the exclusion zone and fall-protection measures remain in place for every worker at wall-top or roof height.

K. Inspection and Correction (Steps 21–24)

1. Sight and string the ridge and eave lines. Confirm both lines are straight within the approved plan tolerance.
2. Verify rafter spacing, seat bearing, ridge contact, roof plane, overhang, pitch, and connection completeness. Complete the Roof Geometry Inspection Checklist below before covering any rafter with sheathing.
3. Correct authorized defects without overcutting or unapproved sistering. Obtain direction from the design professional for any defect outside this project's authorized corrections.
4. Record pattern-rafter dimensions, roof geometry, connections, and inspection results. Complete and sign the roof-framing record before releasing the structure for roof sheathing.