Pitch and slope describe how steep a roof is — and although a framing plan is a flat, top-down view, pitch still shapes what you draw and how you annotate it. This article explains what pitch means and how it appears on a roof framing plan. For the full roof picture, see the roof framing plan guide.

Pitch vs. slope

The two terms are closely related and often used interchangeably:

  • Pitch / slope is the steepness of the roof, expressed as rise over run (how much the roof rises vertically over a given horizontal distance), or as an angle or percentage.
  • A steep roof sheds water and snow quickly and gives attic height; a low slope is flatter and drains more slowly.

How pitch appears on a plan

Because a framing plan is drawn looking straight down, you don't see the slope directly — so it is annotated:

  • A small slope symbol with the rise-to-run ratio (or the angle).
  • A direction-of-fall arrow showing which way water runs.
  • Notes at the ridge, hips, and valleys where planes change.

This is the same annotate-what-you-can't-draw principle used for other out-of-plane information.

Why pitch changes the framing

Pitch is not just cosmetic — it drives the structural system:

  • Steeper, pitched roofs are framed with rafters or trusses running up to a ridge (see rafters vs. trusses).
  • Low-slope / flat roofs have just enough fall to drain and are framed much like a floor — joists spanning between bearing walls. That's why they're laid out like a floor framing plan; see the flat roof framing guide.

So the pitch you choose effectively decides whether you're framing "like a roof" (rafters/trusses) or "like a floor" (joists with a fall).

A note on the tool

Pitch, rafter sizing, and drainage are engineering matters. Framing Plan is well suited to low-slope / flat roofs (framed like a floor) and to the plan-view layout and annotation of any roof — you can add the fall direction and slope notes as annotations. Pitched rafter and truss design belongs to a qualified engineer or truss supplier.

Keep it preliminary

Use a preliminary plan to record the intended pitch, fall, and layout. The structural design — member sizes, drainage, and connections — must be confirmed by a qualified engineer for your project and local code.

Try it

Lay out a low-slope roof or annotate a roof's fall in the browser. Open the framing studio, or read the flat roof framing plan guide.