Rim Board Design and Installation Guide – United States

Introduction

This document presents general information about designing buildings where TECO certified rim boards are used as part of the framing. It provides general information about the intended uses of rim boards, installation of the product, and some acceptable building practices when rim boards are used in light-framed wood structures. It is not intended to be an entirely comprehensive document or cover all possible uses of rim board and it may not apply if rim board is used for other purposes. All rim board is not a direct substitute for structural composite lumber, despite the fact that SCL may be used to make rim board. Consult TECO at www.tecotested.com for clarification of any information presented in this document.

Product Description and Intended Uses

A rim board is a structural element installed around the perimeter of floor framing that closes the ends of joists and performs the tasks of transferring vertical and horizontal loads to structural wall components below. The solid rectangular profile throughout its depth allows rim board to serve as an attachment surface for sheathing, weather barriers, siding and deck ledger boards, etc. Rim board is made from engineered wood products like OSB, plywood or structural composite lumber and are most commonly used in floor systems that are framed with I-joists. Because it is an engineered wood product, rim board can be manufactured in a variety of standard depths (Table 1) that match the depth of I-joists used to frame the rest of the floor system.

TECO defines two grades of rim board in RB 133 Rim Board Product Standard, they are Standard and Performance. While both grades can be used to span openings in a foundation or over a wood-framed wall system, the Performance grade has higher design values and is suited for use in applications where greater strength is required. Proper nailing of the floor sheathing to the tops of the structural floor joists and the rim board, and proper attachment of the rim board to the framing below, results in individual structural elements that work together as a structural floor system.

Table 1. Common dimensions of Rim Board

Identification of Certified Products

TECO certified rim board must be identified with the following information:

• Name of the manufacturer or the TECO mill number (posted on TECO's web site);
• TECO's registered Certification Mark;
• Grade of the rim board;
• Performance Category;
• Thickness; and
• The RB 133 standard.