Five Common Types of Rafters Used for Roof Framing

Rafters are the fundamental members of roof framing, carrying loads from the roof deck to the walls. Understanding the main rafter types helps builders select the right shape, orientation, and connection details for a safe, efficient, and code-compliant roof. This article highlights five common rafter types frequently used in residential construction, outlining their purpose, advantages, and typical applications in American building practice.

Common Rafters

Common rafters are the sloped members that run from the ridge beam or ridge board down to the wall plate. They form the basic framework of many gable and shed roofs. Located along the interior width of the roof, they provide the foundational support for the sheathing and upper roof layers. Common rafters are usually cut square at the bottom and may require a birdsmouth notch to seat securely on the wall plate. They are versatile for many roof styles and easily adjusted to different spans with appropriate structural sizing.

Jack Rafters

Jack rafters are shorter rafters that run from the ridge toward the wall plates, terminating at the building’s exterior walls or intersecting with hip, valley, or additional rafters. They fill in the gaps created by the overhanging edge of the roof and often work with a series of common rafters to complete the roof geometry. Jack rafters are sized smaller than common rafters and require precise layout to ensure seamless connections at joints and at the ridge line. Their proper placement reduces wood use while preserving roof strength.

Hip Rafters

Hip rafters run from the top corner where two roof planes meet down to the wall plate at the outer corners of the building. They carry load from the roof surfaces adjacent to the corners and transfer it toward the outer walls, contributing to roof stability in hip-style roofs. Hip rafters are typically cut with bevels at both ends to connect with ridge, side rafters, and wall plates. Accurate layout and cut angles are essential to prevent misalignment and ensure a tight, weather-tight fit.

Valley Rafters

Valley rafters descend from the ridge at internal angles where roof planes intersect, directing load toward the center of the building. They form the internal “V” shape of valley roofs and often work in concert with common and jack rafters. Valley rafters must be precisely cut to meet at the ridge and at their intersections with opposing rafters, as poor joints can create gaps or weakening stresses. In some designs, valley rafters may be reinforced with additional members or hangers to maintain alignment under load.

Rake Rafters

Rake rafters, or barge rafters, run along the sloped edges of the roof from the gable end to the ridge. They define the outer edge of the roof plane and help establish the roof’s silhouette. Rake rafters are usually decorative as well as structural, and they often require careful alignment with the fascia and soffit lines. In some designs, rake rafters are paired with decorative fascia boards or cornices to enhance curb appeal while providing necessary edge support for the roofing deck.

Practical Considerations And Design Tips

Choosing the right rafter type depends on roof geometry, span, load requirements, and local building codes. Key considerations include:

• Span and load: Larger spans or heavier snow loads may require larger or additional members, or alternative framing such as trusses.
• Connections: Birdsmouth joints, bevel cuts, and tie-ins must be accurate to ensure load transfer and prevent gaps.
• Material quality: Use kiln-dried lumber or engineered wood where appropriate to minimize warping and improve strength.
• Ventilation and moisture: Adequate spacing and proper flashing around joints help prevent rot and prolong roof life.
• Code compliance: Always verify local codes and manufacturer specifications for rafter sizing and connection hardware.

Quick Reference: Typical Roles Of Each Rafter Type

The following is a concise summary of each rafter’s primary role in common residential roofs:

• Common Rafters — Primary slope members forming the main roof framework.
• Jack Rafters — Shorter members completing the edge-to-ridge geometry in larger roofs.
• Hip Rafters — Transfer roof loads at exterior corners, contributing to stability in hip roofs.
• Valley Rafters — Carry interior loads where roof planes intersect, directing load toward the center.
• Rake Rafters — Define the roof’s outer edge and contribute to the visual line and edge support.

By understanding these five common types of rafters and their roles, builders can design safer, more efficient roof systems that align with modern construction practices and American building standards. This knowledge also supports better planning for inspections, material procurement, and long-term maintenance of roof framing.