Roofing joists also join the building’s opposite walls to support the floor above and the ceiling by transferring the roof’s weight to the vertical columns and into the foundation. Roof Joist Spacing GuideĪ roofing joist is a parallel horizontal member or beam that runs across an open space, which can either be laid pitched or flat, exposed or concealed, depending on the construction. In addition, the standard roof rafter spacings commonly used for most building structures are 16″ and 24″. However, the structural engineer may determine other roof rafter spacing measurements, and these may vary depending on the contributing factors affecting it. The International Residential Building Code (IRC), which is the basis of most North America’s building coide, identifies these standard industry measurements.
The standard roof rafter spacings measured on-center are 12″, 16″, 19.2″, and 24″.
Rafter Spacing Chart Source: lincoln.ne.gov What Is The Standard Roof Rafter Spacing? Still, it’s best to follow the guidelines provided by the Building Code or a Structural Engineer to prevent unnecessary calculation errors and ensure a local Building Department approves it. Remember that using this rafter spacing calculator may provide an accurate estimate. Best Lawn Care Service for Service Dogs.
