Rim Board

Rim board ™ sometimes called a rim joist, band joist, or band board ™ is simply a board at the end of an I-joist that closes off the system. Rim boards are typically nailed to the ends of the joists to help provide joist lateral stability. A rim board for an I-joist system must have dimensional stability compatible with an I-joist. It can be either a rectangular or an "I"-shaped section.

Sawn lumber is not permitted as a rim in engineered wood systems. Sawn lumber depths are not compatible with typical I-joist depths. Additionally, lumber shrinks as it dries after installation.

In addition to providing joist lateral stability, rim boards typically perform the functions listed below:

• Transfer vertical loads from a wall above to the wall below. Note that the vertical loads may be uniformly distributed wall loads or concentrated post or cripple loads. Both types of loads must be adequately transferred.

• Transfer diaphragm shear from the floor or roof sheathing to the wall below.

• Transfer shear forces from the wall above to the wall below.

• Provide a solid attachment for exterior deck ledgers when required.

• Provide a flat nailing surface for siding attachment. Note that a non-structural filler can be added to an "I"-shaped rim board to provide a flat surface for siding attachment.

RedBuilt™ offers a number of rim board solutions depending on the application. For additional information see Frequently Asked Questions (FAQs) or contact Technical Support.