Partner Products

We're using a lot of Oriented Strand Board (OSB) in the construction of this year's Project House to deck the sub-floor, to sheathe the exterior of the home, and to sheathe the roof. All of the OSB in the Project House was provided by the Potlatch Corporation.

In the late 1970s, OSB evolved from a product called "waferboard". OSB, like waferboard, is made of strands, flakes or wafers of wood sliced from small diameter logs. Unlike waferboard, however, OSB's strands are "oriented" in layered mats in a cross-grain configuration that greatly increases the strength and durability of the product and gives OSB performance and design characteristics that are roughly equal to those of plywood. In fact, over the last decade, OSB has been replacing plywood as the sheathing and decking choice in residential construction. OSB now accounts for over 50% of all residential structural sheathing used in new construction. *

Use of Treated OSB in the Project House

As engineered wood technology has advanced over the years, many refinements and improvements have been made, including the introduction of pressure-treatment to make OSB resistant to termites, surface mold and fungal rot. We have used Potlatch's "OXTerminator" brand pressure-treated OSB to sheathe the exterior and the roof. These panels are treated, throughout the panel, with a proprietary copper complex that has been EPA-approved for use in residential construction. Termites and fungal microorganisms have a natural aversion to copper. These "new generation" copper-based preservatives are replacing the arsenic-based compounds that were used in residential construction for decades.

Mold-related illnesses are quickly becoming a high-profile issue in the building industry. Millions of dollars in lawsuits and cleanup are focused on toxic mold-related illnesses. By using OSB that resists the growth of surface mold and fungal rot, we're adding an extra layer of protection and durability to the Project House.

Just as the wafers that make up the OSB can be treated with preservatives to protect against termites and mold, they can also be infused with high-grade waterproof and boil-proof resin binders to increase the product's internal strength, rigidity and moisture resistance. The OSB we've used on the sub-floor, Potlatch's "OxTreme" ¾" Sturd-I-floor, has been fortified with increased amounts of wax and resin, giving it exceptional water-repellent characteristics.

The OxTreme sub-floor addresses the well-known builder concern over edge-swelling of OSB during the construction process. There can be a period of up to several weeks between the time the sub-floor is laid and the roof goes on, exposing the flooring to the elements. The increased amount of wax and resin in OxTreme, and the added water-repellency, can eliminate the need to sand the sub-floor prior to the installation of final floor covering.

Contact Information:
Potlatch Corporation
(800) 750-3850

*Source: Potlatch Corporation