Hip Rafter - Diagonal Hip Roof Framing Member Guide

A hip rafter is the diagonal roof framing member that runs from an outside building corner up to the ridge in a hip roof.

What It Is

On a hip roof, the hip rafter forms the sloped outside corner where two roof planes meet. It carries jack rafters from both sides and helps define the shape and load path of the roof framing at the corner.

Because it runs diagonally and supports shortened rafters, a hip rafter is usually larger or specially sized compared with common rafters. Layout errors, sagging, or settlement at this member can distort the roof planes and show up as uneven roof lines or finish cracking below.

Where It Is Used

Hip rafters are used in hip roofs over houses, porches, garages, and additions where roof planes slope down on all sides. They are part of the framing structure and are usually hidden above the ceiling or attic finish.

How to Identify One

You can identify a hip rafter in an unfinished attic by finding the diagonal member that runs from the exterior corner toward the ridge board or ridge beam. From outside, the roof hip itself marks its location even though the framing member is hidden under the roof covering.

Replacement

Replacement or reinforcement is needed when the member has rot, insect damage, fire damage, structural cuts, or severe sagging. Because it is a primary roof-framing member, repair usually requires engineered sizing, temporary shoring, and significant roof or ceiling access.