Residential construction is the single largest market for solid wood products in the U.S. While that may not be surprising, it’s interesting to note that a large percentage of this demand for new wood is not to build new housing, but to replace or repair materials that are damaged or rotting. Not only do replacement materials increase costs for builders, but deteriorating wood shortens the life of homes.

Durability is a key factor in determining whether a home can be considered green. One way builders can create more durable homes is by using I-joists.

I-Joists are engineered wood structural members that can be used in residential and light commercial construction in place of dimensional lumber joists, such as 2x10s and 2x12s. I-Joist production is more environmentally responsible because it can make use of relatively small, faster growing trees of many species as opposed to dimensional lumber joists which must be milled from larger, and thus older, trees.

The benefits of I-joists when compared to dimensional lumber are making them an increasingly popular choice among homebuilders. I-Joists are manufactured in a factory-controlled setting to meet specific quality standards. As a result, they have a more uniform and predictable size, shape, strength, stiffness, and moisture content than dimensional lumber.

With I-joists, you can forget about squeaky floors, cracked drywall, and misaligned framing. You won’t find the twisting, bowing, and shrinkage that naturally occur in dimensional lumber joists, leading to these problems. I-Joists are also lighter weight than comparably-sized dimensional lumber, making them easier to handle on the jobsite and requiring less labor, which saves time and money.

In addition, because I-joists have greater load-bearing capacity than dimensional lumber, and they are available in longer lengths, homes can have larger wide-open spaces without needing supporting walls under the floor. I-Joists are available in a range of lengths, flange widths, and depths. Flange widths range from 2 ¼ to 3 ½”, and depths range from 9 ½ to 24”. Most I-joists have knockouts or pre-scored holes approximately every 2’ o.c. for small water supply pipes and electrical wiring. Large holes for plumbing drain lines and HVAC ducts can be cut as long as the manufacturer’s cutting guidelines are followed.

For more information
Read our related article, “10 Tips for Handling and Installing I-Joists,” or visit the Wood I-Joist Manufacturers’ Association for a list of I-joist manufacturers.

More Best Practices® in wood framing for floors, walls, and roofs can be found in BuildIQ University’s Framing suite of online training courses.