Rim Board FAQs

Is there a test and evaluation criteria for rim boards?

The ICC Evaluation Service has established Acceptance Criteria for Rim Board Products, AC124. This criteria was developed by ICC-ES engineering staff and a committee of industry engineers from leading engineered wood products companies. AC124 evaluates potential rim board products for vertical and lateral load capacities and durability. RedBuilt� rim board is tested and evaluated in accordance with AC124.

How does the APA EWS "Performance Standard for APA EWS Rim Boards� (PRR-401) fit into the above test and evaluation criteria?

ICC-ES AC124 is a true performance standard. It specifies test methods and evaluation criteria, but does not assign design values to particular classifications. PRR-401 fills this gap and assigns design values for the Rim Board Plus product classification. PRR-401 uses AC124 performance criteria to verify each trademarked product attains the design values established in PRR-401.

Can rim boards be installed flush with the exterior face of the wall sheathing?

No. Rim boards must fully bear on the plate below to develop full published vertical and lateral capacities.

I am using T&G floor sheathing and the tongue (or groove) is directly over the rim board. Is this appropriate?

Generally speaking this detail is not recommended. RedBuilt™ LVL rim board vertical load capacities are based on the assumption of full bearing (i.e. no tongue or groove over the rim board). The tongue (or groove) will not directly transfer vertical load and therefore only one edge of the rim board is vertically loaded, which directly reduces bearing capacity. Additionally this eccentric loading reduces published vertical load capacities.