How neighboring faces connect

Faces that touch should share their corners and edges exactly. From the shared edge and the Google heights Cali-Graf works out whether it’s a ridge, a hip, a valley or a wall — and that sets the fire setbacks and pathways along it.

Two faces drawn side by side with a thin gap between them look the same on screen, but the editor sees two separate roofs, each with its own outer edges. Joined faces give it the real shape of the roof.

Shared corners and edges

When you trace a face and click near a corner or an edge of a face you already drew, the click snaps to it. Faces drawn this way share the corner — move it later and both faces follow. Splitting a face with a line gives two joined faces right away. See Draw roof faces.

What the shared edge becomes

For every edge between two faces, Cali-Graf looks at which way each face slopes away from it:

The two faces…	The edge is
both slope away and the edge is level	Ridge
both slope away and the edge runs down the roof	Hip
both slope toward it	Valley
one continues into the other at another pitch	Pitch change
meet more than 0.5 m (1.6 ft) apart in height	Wall

Edges on the outside of the roof become an eave (level, at the bottom), a ridge (level, at the top) or a rake (sloped). Roof edges on the right — with Roof picked — shows them all by color — see Edge types: eave, rake, ridge, hip, valley.

Why it matters

Fire setbacks depend on the edge type: a strip along the ridge, along hips and valleys under some rules, none at eaves under California code — see Fire setbacks on the roof.
Fire pathways run along rakes, hips and valleys.
Pitch and direction are measured face by face, so a face that wrongly spans two slopes gets a pitch that fits neither.

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Updated October 6, 2026