When building a shed, one of the key structural elements to consider is the spacing of the roof joists. Roof joists provide support for the roof and help distribute its weight evenly. In this blog post, we’ll discuss how far apart roof joists should be for a typical shed, why spacing matters, and provide you with practical examples.

Understanding Roof Joists

Roof joists are horizontal framing members that run from one side of the shed to the other, supporting the roof’s weight and transferring it to the shed’s walls. Properly spaced roof joists are crucial for the structural integrity of your shed.

Typical Roof Joist Spacing for a Shed

The spacing of roof joists in a shed can vary depending on factors like the shed’s size, local building codes, and the weight of the roofing material. However, for most sheds, the typical spacing for roof joists is:

  • 16 inches on center (OC): This means that the joists are spaced 16 inches apart from the center of one joist to the center of the next. This is a common and reliable spacing for shed roofs.

Why Roof Joist Spacing Matters

Proper roof joist spacing is essential for several reasons:

  1. Structural Integrity: Adequate spacing ensures that the roof can bear the weight of the roofing materials and any additional loads, such as snow in winter or wind.
  2. Preventing Sagging: Closer spacing helps prevent the roof from sagging over time, ensuring it remains sturdy.
  3. Roof Material Support: The spacing of roof joists also affects how well the roofing material is supported. Proper spacing reduces the risk of the roofing material sagging between joists.

Examples of Roof Joist Spacing

Let’s consider a practical example:

Example 1: If you have a small 8 ft. by 10 ft. shed, the roof joists would typically be spaced 16 inches on center. This means you’d have six evenly spaced joists running across the 8 ft. width.

Example 2: For a larger shed, such as a 12 ft. by 16 ft. one, the roof joists would also typically be spaced 16 inches on center. In this case, you’d have nine joists running across the 12 ft. width.


When it comes to building a shed, the proper spacing of roof joists is crucial for the shed’s structural integrity and the longevity of your roof. While 16 inches on center is a common and reliable spacing for most shed roofs, always check your local building codes and the specific requirements of your shed’s design to ensure you get it right. Properly spaced roof joists will help your shed withstand the elements and provide you with a secure and durable structure for storage or any other purpose you have in mind.


As a civil engineer and roofer, I love to share the experience that I have gained through the last couple of years. In the roofing industry, practical experience is a very crucial fact that can help you a lot. Hence, I want to help you with my blog.

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