Southern Pine Floors

The most common thicknesses of Southern Pine flooring are 1-inch and 1¼-inch nominal (3/4-inch and 1-inch actual). Standard widths range from 2-inch nominal (1-1/8˝ actual) to 6-inch nominal (5-1/8˝ actual), though wider widths are also manufactured. Strip flooring is a term given to material that is 3½-inch or narrower and plank flooring is classified as material that is 4 inches and wider.

Southern Pine flooring is available in lengths ranging from 8 to 16 feet, and longer or custom lengths may be available on a special-order basis. Finger-jointing is increasingly used to produce longer lengths, making more efficient use of high-grade stock. If not otherwise specified, Southern Pine flooring will have tongue-and-groove edges with plain ends.

There are three main grain specifications:

• End-matched flooring. End-matched floorboards have a tongue or a groove on each end. This tongue-and-groove pattern on the strip flooring sides and ends provides load-bearing capabilities for screed (the subflooring nailing base) installation systems where end joints occur between the screeds. End-matching also reduces the amount of strip end cuts in comparison to plain-end flooring, which can reduce waste and labor. As a log is sawn, its position relative to the saw cut determines the wood grain’s orientation relative to the flooring wear surface. 
• Flat or mixed grain flooring: Commonly referred to as flat-sawn flooring, this specification has a growth ring configuration parallel to the wearing surface, but it generally is graded and sorted respective to the wood grain orientation and consequently is considered mixed grain flooring.
• Edge or vertical grain flooring. This is where the growth rings are perpendicular to the flooring wear surface. This product is equivalent to quarter-sawn material in hardwood flooring. Edge-grain flooring has a harder wearing surface than flatgrain material and is desirable for high-traffic areas such as kitchens, hallways, or family rooms. Edge-grain material’s resistance to wear and indentations also makes it popular for commercial or institutional use in offices, schools, retail, or industrial environments.

Typically, Southern Pine flooring is manufactured with a stress-relief pattern on the underside of each piece to minimize the effects of moisture-related dimensional changes. Relief types include a shallow, wide groove known as a hollow back, or a series of grooves commonly referred to as scratch-back.