Roof Framing Plan: A Practical Guide

A roof framing plan is the structural drawing showing how the roof system is built — the rafters, beams, trusses, joists, decking, and connections that carry roof loads down to the bearing structure below. It is one of the most consequential sheets in the structural set because it is also one of the most visible to contractors during construction. This guide covers what is on a roof framing plan, how to read one, and the conventions worth knowing.

What is a roof framing plan?

A roof framing plan is a top-down (plan view) drawing of the roof structural system. It shows every structural member that carries roof loads: rafters, ridge beams, hip and valley beams, trusses, joists, purlins, blocking, and the bearing walls or beams that support all of those.

The plan is drawn at the structural level — what the framer sees during construction, before sheathing and roofing materials go on. The architectural roof plan, which shows roofing materials, slopes, drains, and finished surfaces, is a separate drawing produced by the architect.

What appears on a roof framing plan

A complete roof framing plan typically includes:

• All roof framing members with size, spacing, and direction (e.g. "2x10 @ 16" o.c.")
• Beams, headers, and girders with size and span callouts
• Trusses with truss type designation and spacing
• Bearing walls and bearing points where loads concentrate
• Hips, valleys, ridges, and roof breaks
• Skylights, chimneys, mechanical curbs, and other roof penetrations
• Cantilevers, overhangs, and structural projections
• Posts, columns, or knee walls supporting the roof
• Connection callouts (hangers, hold-downs, straps) referenced to detail sheets
• Reference to the structural notes and detail sheets
• Roof sheathing requirements (often noted on the plan)

How to read a roof framing plan

A few conventions make roof framing plans much faster to read once you know them:

1. Member arrows. Roof framing members are typically drawn as long parallel lines with arrows or end caps showing direction. The direction tells you which way the rafters or joists span.
2. Spacing callouts. "2x10 @ 16" o.c." means 2x10 lumber rafters spaced 16 inches on center. The on-center spacing matters as much as the size.
3. Bearing lines. Heavier line weights typically indicate bearing walls, beams, or other points where roof loads transfer down to the structure below.
4. Hip and valley diagonals. Hips and valleys appear as diagonal lines connecting ridge ends to outside corners (hips) or interior corners (valleys).
5. Truss callouts. Pre-engineered trusses are usually shown as a single line with a truss tag (T1, T2, etc.) referencing a separate truss schedule.
6. Cross-section bubbles. Section cuts show how the roof is built up vertically and reference detail sheets for connection specifics.

Roof framing plan vs roof plan

These are two different drawings produced by two different parties. The roof framing plan is structural — produced by the structural engineer, showing the roof structure. The roof plan (or architectural roof plan) is architectural — produced by the architect, showing the roof from above with materials, slopes, drains, vents, mechanical units, parapets, and other surface-level information.

On a typical project both sheets exist and both are needed. The framer builds from the roof framing plan. The roofer works from the architectural roof plan. The general contractor coordinates both.

Conventions worth knowing

A few conventions are nearly universal on roof framing plans:

• Solid lines for primary structural members visible from below
• Dashed lines for members hidden above sheathing or by other framing
• Heavier line weights for beams, posts, and bearing elements
• Truss spacing usually shown at 24 inches on center for residential, 48 inches or more for commercial pre-engineered trusses
• Standard rafter and joist spacing of 16, 19.2, or 24 inches on center
• Roof slope shown either as a fraction (e.g. 6:12) or as an angle, with the slope direction marked
• Cantilever distances called out explicitly (e.g. "12\" cantilever")

Common roof framing plan errors

A few errors show up often enough to be worth checking for:

• Missing bearing at concentrated load points (hip and ridge intersections, beam ends)
• Inadequate beam sizes for spans, particularly at long openings or vaulted ceiling areas
• Truss callouts that do not match the truss schedule or that use truss types the manufacturer cannot supply
• Missing or incorrect lateral bracing for trusses and tall rafters
• Roof penetrations (skylights, chimneys, vents) shown on architectural plans but missing from framing plans
• Coordination errors between the framing plan and the wall framing plan below — especially at points where roof loads transfer to bearing walls

Roof framing plan in the structural set

The roof framing plan typically appears toward the top of the structural set, after foundation plans and floor framing plans. The sequence is: foundation plan → first floor framing plan → upper floor framing plans (if multi-story) → roof framing plan → structural sections → structural details. The roof framing plan is read together with the structural sections (which show vertical loading paths) and the detail sheets (which show how connections are made).

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