Wood Flooring Installed Over Edge, Edge Gold and Diamond OSB

TECHNICAL RESOURCE SHEET

WOOD FLOORING INSTALLED OVER EDGE®, EDGE GOLD™ AND DIAMOND™ OSB FLOOR PANELS IN JOIST FLOOR CONSTRUCTION

Weyerhaeuser Edge®, Edge Gold™ and Diamond™ oriented strand board (OSB) flooring panels are high- quality structural panels, considered some of the best OSB products on the market. They are manufactured by combining precisely cut wood strands with controlled amounts of wax and resin, which are then pressed together under high temperatures to form panels maximized for strength, stiffness, and stability. Edge, Edge Gold and Diamond floor panels feature limited warranties against delamination. Edge Gold panels include a limited 200-day no-sand warranty and Diamond panels include a limited 500-day no-sand warranty. Reliability of performance is the reason for Edge, Edge Gold and Diamond floor panels’ proven success as an ideal solution under hardwood flooring.

A Proven Product with a vapor barrier ground cover installed) Leading wood flooring manufacturers and major both prior to and after installation. If installing wood flooring associations recognize OSB as during warm months, the building must a proven substrate material for wood flooring be well ventilated; during the winter applications. OSB is more resource efficient, months, heating should be maintained structurally consistent, and less prone to near occpancy levels. delamination than plywood. • Use Edge, Edge Gold or Diamond floor panels that are at least 23⁄32 performance category. The National Wood Flooring Association (NWFA) Verify that floor joist spacing meets the wood recommends 23⁄32 performance category or flooring manufacturer's recommendations. thicker OSB panels for use under wood flooring. NWFA Installation Guidelines(1) recommend (1) at least 23⁄32 performance category panels NWFA Installation Guidelines Adequate substrate material is only one of 23 for floor joists spaced 19.2" o.c. or less, and recommend at least ⁄32 many factors to consider when installing wood ⅞ performance category panels for floor performance category panels for flooring. Proper floor preparation and structural joists spaced 24" o.c.. See the following table: floor joists spaced 19.2" o.c. or less, support, moisture acclimation, and quality and ⅞ performance category installation practices are also critical elements Recommended OSB floor panel thickness in any successful wood flooring application. panels for floor joists spaced 24" o.c.. Joist Spacing (in.) Minimum OSB Performance Category

S ≤ 19.2 23⁄32 Installation Guidelines 19.2 < S ≤ 24 7⁄8 Most building codes, along with a number of 24 < S ≤ 32 11⁄8 industry associations, have published specific guidelines for installing OSB floor • To increase floor stiffness and help prevent panels. Many wood flooring manufacturers have squeaks, vibrations and bounce, glue the also established specific installation require- panels to the joist in addition to nailing or ments and will only warrant their product if it screwing. Weyerhaeuser recommends using has been installed per those specifications. In a subfloor adhesive that has been qualified general, most guidelines for proper installation as a Class 1/8 in., Type P/O subfloor of an OSB floor system, and the wood flooring adhesive in accordance with installed over it, include the following ASTM D3498-19 (see TB-131). recommendations: • When installing the floor panels, leave a ⅛" • To minimize moisture issues, the gap at all the ends and edges of each panel to basement floor should be poured, all allow for normal expansion. The tongue-and concrete and drywall should be cured, and all groove profile on Edge, Edge Gold and doors and windows should be in place prior Diamond floor panels automatically gaps the to installing wood flooring. The crawlspace long edge of the panel. For improved must be kept dry (i.e., properly drained

WEYERHAEUSER.COM 1.888.453.8358 Wood Flooring Installed Over Edge®, Edge Gold™ and Diamond™ OSB Structural Panels in Joist Floor Construction

perfomance, the tongue-and-groove edges absorb moisture from humid air when in can also be glued together. storage and during shipping. Therefore, schedule delivery of the flooring only after the • For panels 1" thick or less, use 8d (0.131" house has dried. Unwrap flooring and allow x 2½") nails to completely fasten the panel it to acclimate in the home with the HVAC to the joists. For panels thicker than 1", use system operating, in accordance with the 10d (0.148" x 3") nails. Screws of an manufacturer’s recommendations and NWFA equivalent root diameter and length may be Installation Guidelines, prior to installation. used instead of nails. When fastening with screws, Weyerhaeuser recommends using During installation follow manufacturer screws from a manufacturer that can provide recommendations and NWFA Installation an ICC-ES Evaluation Report. Do not use Guidelines for acceptable differences in drywall screws. MC between floor panels and acclimated flooring. Typically, the difference in MC Keep all fasteners at least 3⁄8" from panel should be no more than 4% for solid wood edges. Recommended maximum fastener strips less than 3" wide or parquet wood spacing is 6" o.c. along supported panel flooring, and no more than 2% for planks The overall design of a floor system edges and 12" o.c. along intermediate 3" and wider or end-grain flooring. A pin- — including joist depth, spacing, and supports (joists) in the panel field, unless type moisture meter can be used to check type of floor panel used — plays a specfied otherwise. MC of floor panels and hardwood. significant role in the success • As the floor panels are installed, make sure • Once the floor panels are properly of a wood flooring installation. they stay flat (no high or low spots) and sand prepared, the work area is enclosed, and any raised joints. Lightly countersink wood flooring is acclimated, it should be protruding nail heads and re-nail areas of installed by a professional following the the floor panels as needed to help eliminate recommendations of the flooring nail pops and potential squeaks. With manufacturer and NWFA Installation screws, tighten heads slightly into panels to Guidelines(1). ensure panels are securely fastened against framing. While these guidelines will help ensure a successful wood flooring installation, the • Prior to laying the wood flooring, OSB floor overall design of a floor system—including joist panels should be free of debris and dust. depth, spacing, and type of floor panel used— They should also be dry, with a moisture plays a significant role as well. For additional content of not more than 4% over the information on installing Weyerhaeuser Edge, expected in-use average moisture content Edge Gold or Diamond floor panels, visit of the flooring. See the following table: weyerhaeuser.com. In cases where a higher Average Yearly MC for Wood in performance floor system is desired, call your Various North American Regions(2) Weyerhaeuser sales representative for design Region Average MC Range of Wood (%) assistance. Coastal 8–12 Inland 6–10 References Drier Climates 5–9 1. Wood Flooring Installation Guidelines, National Wood Flooring Association, 2019, nwfa.org. 2. Managing Moisture and Wood, Building Performance • Wood flooring is generally manufactured to a Series No. 6, Canadian Wood Council, 2004. moisture content (MC) of 6%–9%, but it can

For more information about storage, safety, and installation of Edge, Edge Gold and Diamond floor panels, see the Technical Resource Sheet,Floor, Roof and Wall Panel Installation (OSB-4004), or contact your Weyerhaeuser representative.

1.888.453.8358 weyerhaeuser.com [email protected]

July 2021 Reorder OSB-4005 This document supersedes all previous versions. If this is more than , Weyerhaeuser and Edge are registered trademarks, Edge Gold and Diamond are trademarks of one year old, contact your dealer or Weyerhaeuser representative. Weyerhaeuser NR Company. © 2021 Weyerhaeuser NR Company. All rights reserved. Printed in the USA.