Messages and Online Forum Q&A

Re: OSB vs. Plywood

From: info@builderswebsource.com
Category: Carpentry and Framing
Remote Name: 63.198.181.43
Date: 03 Nov 2002
Time: 01:59 AM

Comments

For subfloor applications, either OSB or plywood will perform with similar structural properties. The outside edges of OSB, however, can swell when subjected to moisture or rain on the job. One manufacturer offers OSB (Norbord - http://www.norbord.com/), which has been specially treated to mitigate swelling under wet conditions. However, most OSB is limited to approximately 3/4" thickness. For this reason, many builders prefer T&G plywood, such as APA-rated Sturd-I-Floor® or similar product. The recommended thickness depends on the span of the joists underneath. However, for typical joists on 16" centers, we recommend nothing less than 3/4" (23/32") subflooring. In premium homes, 1-1/8" plywood is sometimes used (we did this in our own home). This provides a super stiff floor (assuming the joists are properly sized to begin with) and is ideal when using a mortar bed or cement board underlayment when setting tile, marble or other masonry surfaces. We always recommend that your glue and screw the subfloor to minimize squeaking. Gluing also creates a stiffer web, helping to unify the structure. If you're installing the subfloor yourself, use stainless steel screws. They cost a little more, but they're strong, durable, and corrosion resistant.

Builders Websource®

Article Tools

Builders Websource® is a corporate member of ASTM International—a non-profit engineering body dedicated in part to the standardization of building materials specifications, products, systems, and test methods for improved health, safety, and reliability of residential and commercial structures.

Copyright © 1999 - 2008 Builders Websource®, an InBuild™ company. All rights reserved.