Home Innovation Research Labs and the USDA Forest Service Forest Products Laboratory recently released a new guide to help identify design principles and construction practices to improve the moisture performance of wood-framed balconies and decks.

The Durable Solutions for Balconies and Decks illustrated guide covers all phases of the construction of wood-framed balconies and decks, including building code considerations, design, building material selection, and ongoing maintenance.

The guide focuses on cantilevered balcony designs, which have suffered catastrophic structural failures, such as the 2015 balcony collapse in Berkeley. The guide provides detailed illustrations of best practices and checklists for inspection and maintenance to ensure the safety of home owners and users of balconies and decks.

A critical area for any cantilevered balcony design is the interface between the cantilevered members and the exterior walls of the building. In addition to sloping of the walking surface and waterproofing membrane, flashing of the balcony and any doors providing access to and from the building must be carefully integrated with the water-resistive barrier on the exterior wall and the waterproofing membrane of the balcony to keep water out of the building envelope and promote drying of any components that get wet.

The guide includes best practices and construction details for this interface where low-height thresholds are required at balcony doors to meet Fair Housing Act accessibility or Americans with Disabilities Act (ADA) requirements.

A technical advisory group — which included practicing architects and engineers, wood industry representatives, and building science experts — provided input on the creation of the guide. In addition to funding from the Forest Products Laboratory, AGS Stainless, Inc. provided steel railing products for the mockups constructed at Home Innovation’s facilities.

Download the guide. For questions, contact Gary Ehrlich, who participated on the advisory group, at gehrlich@nahb.org or 800-368-5242 ext. 8545.