Subfloors are typically viewed as a commodity, and regardless of whether they're made of oriented strand board (OSB) or plywood, they need to meet the same structural ratings. But some manufacturers aim to move subfloors out of the commodity bargain bin. They are improving their subflooring products–particularly the OSB selections–branding them, and marketing them to stand out from the masses. Additionally, companies have started to highlight how subflooring products can add green benefits to a home.

This shift toward premium status follows a decade in which OSB has slowly shed its old nickname of "flake board" and moved from a 50% share of the subflooring market to what manufacturers say is probably closer to 80%. But even today, some builders prefer plywood over OSB for a variety of reasons, including plywood's inherent ability to resist moisture better than standard OSB and its higher-end appearance.

Now OSB is fighting back even harder, with improvements such as increased moisture resistance and the addition of printed nailing and framing guides that can help builders save time during construction.

The Rain's a Pain

When OSB gets wet, its edges swell. As a result, builders have to make sure the floor of a home is flat by sanding the subfloor. But by tweaking wax and resin treatments along with the structure of OSB panels, companies have begun to turn out increasingly more moisture-resistant OSB products.

One of the newest releases is Ainsworth's pointSIX Durastrand Flooring, an OSB subfloor. The company tapers the edge of the panel by 0.6 millimeter to give it room to swell if it gets wet. The taper is enough for the manufacturer to offer a 180-day no-sand guarantee, but not enough for the product to need to be installed differently or for a builder to worry about gaps if the product does not get wet, says Robert Fouquet, Ainsworth's vice president of marketing and sales.

To increase the moisture resistance of its OSB lineup, Louisiana-Pacific added two premium products with higher levels of waxes and resins to resist edge swell. Its LP TopNotch 350 series carries a 100-day no-sand warranty (Circle 102), and the 450 line has a 200-day no-sand warranty.

"I think just the addition of the premium products has been the biggest change," says Brian St. Germain, OSB quality and technical manager for Louisiana-Pacific. "Over the course of the last five to 10 years, it's become more popular with builders. It offers reduced labor, and is a better overall product."

Norbord has offered its premium OSB subfloor, Stabledge, for about 10 years, says Doug McNeill, the company's marketing manager. Last year, Norbord introduced a mid-priced subfloor, Pinnacle (Circle 105), and reformulated its commodity subfloor, TruFlor, in 2008. Pinnacle offers a 50-year limited warranty and 100-day no-sand warranty, while TruFlor has a 25-year limited warranty, an improvement from the former commodity panel that did not offer a warranty. Stabledge leads the pack with a 50-year limited warranty and 50-year no-sand warranty.

Improvements in resins, the way the board is laid up, and press and cycle times for the manufacture of subfloors make for better products at all levels, McNeill says.

"Builders not wanting to sacrifice quality can take advantage of a slightly lower-cost subfloor and not have any problems," he says.

Huber Engineered Woods has continued to adjust the way its OSB subfloor, AdvanTech, resists moisture. The resins bond chemically to the wood in AdvanTech, acting like Gorilla Glue and making it harder for water to penetrate, says Charlie Robinson, general manager of AdvanTech flooring. The company also sands the top and bottom of the product so it "has the sheen of plywood," and is denser, making it more difficult for water to find a way into the board. These measures allow the company to back a 300-day no-sand warranty.

Most recently, the company has added a fastening guide to the surface of the offering. Different symbols on the guide indicate placement for fastening at 16-inch, 19.2-inch, and 24-inch on center. Home inspectors can simply glance at the board to see it is fastened correctly, and the guide speeds up the fastening process by about 25%, Robinson says.

Weyerhaeuser has also added a nailing guide to its iLevel Edge Gold OSB subfloor. Different shapes mark 16-inch, 19.2-inch, and 24-inch spacing.

Green Subfloors

As builders look for more ways to gain points in green rating systems and use more green products overall, most OSB and plywood subfloor manufacturers have started using certified wood from the Sustainable Forestry Initiative (SFI). Companies also stress how the strength of their product can help builders use advanced framing techniques to become more efficient with building materials.

Georgia-Pacific has SFI certification for its engineered wood products, and recently added NAHB "Green Approved" certification to products including DryPly plywood subfloor and DryGuard OSB subfloor.

"We get more and more questions from builders [whether our products meet green ratings]," says Pat Lynch, vice president of sales for Georgia-Pacific's Structural Panels group. "This gives them that peace of mind that these products can help earn points."

Last year, Norbord made its subflooring products available with either SFI Chain of Custody or Forest Stewardship Council certification.

Robinson from Huber says his company gets questions from builders about AdvanTech's ability to support advanced framing techniques. Huber obtained an ESR report from the ICC Evaluation Service to prove that its subfloor could perform with wider framing spacing, he says.

"It can reduce material cost and labor cost," Robinson says. "Advanced framing is something I would keep my eye on."

A majority of these premium products cost more than standard offerings. But as builders continue to demand more value in the products they use to help differentiate themselves in this down market, these improved selections may be one more way their homes can stand out from the rest.