Tips on adding holes to I-joists

Cutting holes in an I-joist is fairly easy to do. However, when it comes to hole size and placement, there are rules that must be followed to ensure they do not affect joist capacity. Here’s more information on cutting round holes as well as some Do’s and Don’ts regarding holes in BCI® and AJS® Joist webs. 

When you’re out in the field and need to cut a hole in an I-joist, the Allowable Hole Table and details in our Western and Eastern Specifier Guides explain where holes of a specific size may be placed. These hole tables consider the maximum uniform load allowed for the corresponding joist depth to ensure its load-carrying capacity is not affected by the hole. However, the Allowable Hole Table in our guides are based on specific span lengths, so they may be a bit conservative for a span that falls somewhere in between.

For the most accurate hole placement, use our BC Calc® sizing software. It can analyze specific hole sizes and locations for the actual joist loading and span condition. BC Calc® analysis often allows for larger holes or placement closer to bearing supports when compared to tables in our printed literature. 

Want to learn about cutting longer, rectangular web holes? This Tech Note will tell you how

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