Grade Descriptions
Southern Pine
Lumber Grade
Descriptions
Different projects require different types of wood, so how do you know what type of Southern Pine lumber is right for your project? That’s where lumber grade descriptions come in.
These lumber grade descriptions serve as a code for everything you need to know about the quality and characteristics of a piece of lumber, so you get what you need for your specific project, whether it’s for commercial, industrial, or residential use.
Southern Pine lumber is typically graded based on appearance and structural characteristics. Each grade details the quality and suitability of the lumber for different applications. They also provide guidance on:
- Structural integrity
- Characteristics and aesthetics
- Durability
- Code compliance
- Quality assurance
Grade Descriptions Based on SPIB Grading Rules
| Grade | Grade Characteristics and Typical Uses |
|---|---|
| See Table 1 for design values | |
| *Dense Select Structural Select Structural *Select Structural Non-Dense | High quality, limited in characteristics that affect strength or stiffness. Recommended for uses where high strength, stiffness and good appearance are desired. |
| *No.1 Dense No.1 *No. 1 Non-Dense | Recommended for construction where high strength, stiffness and good appearance are desired. |
| *No.2 Dense No.2 *No.2 Non-Dense | Recommended for most general construction uses where moderately high design values are required. Allows well-spaced knots of any quality. |
| No.3 | Recommended for general construction purposes where appearance is not a controlling factor. Many pieces included in this grade would qualify as No.2 except for a single limiting characteristic. |
| Stud | Suitable for stud uses including use in load-bearing walls. Composite of No.3 strength and No.1 nailing edge characteristics for a better nailing surface. |
| *Construction (2″ to 4″ wide only) | Recommended for general framing purposes. Good appearance, but graded primarily for strength and serviceability. |
| *Standard (2″ to 4″ wide only) | Recommended for same purposes as Construction grade. Characteristics are limited to provide good strength and excellent serviceability. |
| *Utility (2″ to 4″ wide only) | Recommended where a combination of economical construction and good strength is desired. Used for such purposes as studding, blocking, plates, bracing and rafters. Design values only apply to utility lumber that is 4” wide. |
| Economy (Design values are not assigned) | Usable lengths suitable for bracing, blocking, bulkheading and other general utility purposes where strength and appearance are not a consideration. |
| Grade | Grade Characteristics and Typical Uses |
|---|---|
| See Table 1 for design values | |
| No.1 Prime | Recommended where appearance and strength are a consideration. Grade based on No.1 Dimension Lumber except wane and other characteristics that affect appearance are limited. |
| No.2 Prime | Recommended where appearance and strength are a consideration. Grade based on No.2 Dimension Lumber except wane and other characteristics that affect appearance are limited. |
| Grade | Grade Characteristics and Typical Uses |
|---|---|
| See Table 3 for design values | |
| Dense Select Structural Select Structural | Recommended where high strength, stiffness and good appearance are desired. |
| No.1 Dense No.1 | Recommended for general construction uses. Similar in appearance to No.1 Dimension Lumber. |
| No.2 Dense No.2 | Recommended for general construction uses. Similar in appearance to No.2 Dimension Lumber. |
| No.3 (Design values are not assigned) | Non-stress rated, but economical for general utility purposes such as bracing, blocking, bulkheading, etc. |
| Grade | Grade Characteristics and Typical Uses |
|---|---|
| See Table 2 or SPIB Grading Rules for design values | |
| 750f – 1.4E thru 3000f – 2.4E | Machine Stress Rated (MSR) lumber is evaluated by mechanical stress rating equipment. MSR lumber is distinguished from visually stress graded lumber in that each piece is non-destructively tested. MSR lumber is also required to meet certain visual grading requirements. The grade mark can include “1W” or “2W” if visually graded to the wane requirements for No.1 or No.2 dimension lumber, respectively. |
Mechanically Graded Lumber - Machine Evaluated Lumber (MEL): 4" and less in thickness, 2" and wider*
| Grade | Grade Characteristics and Typical Uses |
|---|---|
| See Table 2 or SPIB Grading Rules for design values | |
| M-5 thru M-42 | Well-manufactured material evaluated by calibrated mechanical grading equipment which measures certain properties and sorts the lumber into various strength classifications. Machine Evaluated Lumber is also required to meet certain visual requirements. The grade mark can include “1W” or “2W” if visually graded to the wane requirements for No.1 or No.2 dimension lumber, respectively. |
| Grade | Grade Characteristics and Typical Uses |
|---|---|
| Design Values by qualification | |
| E-grades | Suitable for use as individual laminations for structural glued laminated timbers. This lumber has been non-destructively evaluated by an American Lumber Standard Committee approved machine. |
| Grade | Grade Characteristics and Typical Uses |
|---|---|
| See Table 1 for design values | |
| See Dimension Lumber Grades | End-glued, face-glued, and edge-glued Southern Pine in glued assemblies, including stress-rated grades of finger-jointed 2″ Dimension Lumber. |
| Grade | Grade Characteristics and Typical Uses |
|---|---|
| See Table 4 for design values | |
| Dense Industrial 72 Scaffold Plank Dense Industrial 65 Scaffold Plank | All Scaffold Plank design values are calculated using ASTM Standards D245 and D2555. These values are modified using procedures shown in “Calculating Apparent Reliability of Wood Scaffold Planks,” as published by the Journal on Structural Safety, 2 (1984) 47-57, and updated in 1993. |
| MSR Scaffold Plank: 2400f – 2.0E MSR Scaffold Plank: 2200f – 1.8E | Dressed to standard dry size prior to machine stress rating, and visually graded to assure that characteristics affecting strength are no more serious than the limiting characteristics for each grade. MSR Scaffold Plank is available 2″-thick only. |
| Grade | Grade Characteristics and Typical Uses |
|---|---|
| See Table 1 for design values | |
| No.1 Dense Stadium Grade No.1 Stadium Grade | For outdoor seating. Free of pitch pockets, pitch streaks and medium pitch on one wide face, but otherwise conforms to No.1 Dense or No.1 Dimension Lumber. |
| Grade | Grade Characteristics and Typical Uses |
|---|---|
| See Table 1 for design values | |
| Any grade of Dimension Lumber | One wide face and both adjacent narrow faces must be free of pith and/or heartwood. Application of the product requires pressure treatment by an approved treating process and preservative for marine usage. |
| Grade | Grade Characteristics and Typical Uses |
|---|---|
| See Table 1 for design values See Table 3 for design values |
|
| Any grade of Dimension Lumber or Timbers | All four longitudinal faces must be free of pith and/or heartwood. Application of the product requires pressure treatment by an approved treating process and preservative for marine usage. |
| Grade | Grade Characteristics and Typical Uses |
|---|---|
| See SPIB Grading Rules for design values | |
| Dense Standard Decking | A superior decking grade, suitable for plank floor where face serves as finish floor. Has a better appearance than No.1 Dense Dimension Lumber because of additional restrictions on firm red heart, pith, knots and wane. |
| Dense Select Decking Select Decking | An excellent decking grade that can be used face side down for roof decking or face side up for floor decking. |
| Dense Commercial Decking Commercial Decking | An economical roof decking which conforms to No. 2 Dimension Lumber characteristics. |
| Grade | Grade Characteristics and Typical Uses |
|---|---|
| See Table 1 for design values | |
| Industrial 55 | Graded as per No.1 Dimension Lumber. |
| Industrial 45 | Graded as per No.2 Dimension Lumber. |
| Industrial 26 | Graded as per No.3 Dimension Lumber. |
| No.1 (Design values are not assigned) | High quality with good appearance characteristics. Generally sound and tight-knotted. Largest hole permitted is 1/16″. Superior product suitable for a wide range of uses including shelving, boxing, crating, and form lumber. |
| No.2 (Design values are not assigned) | Good-quality sheathing, fencing, shelving and other general purpose uses. |
| No.3 (Design values are not assigned) | Good, serviceable sheathing; usable for many economical applications without waste. |
| No.4 (Design values are not assigned) | Admits pieces below a No.3 grade which can be used without waste, or which contain less than 25% waste by cutting. |
| Grade | Grade Characteristics and Typical Uses |
|---|---|
| See SPIB Special Product Rules for design values | |
| Industrial 86 | Appearance is same as B&B Finish for thicknesses of 4″ and less and widths 12″ and less. Larger sizes conform to Dense Structural 86 Structural Lumber except for dense grain requirement. |
| Industrial 72 | Appearance is same as C Finish for thicknesses of 4″ and less and widths 12″ and less. Larger sizes conform to Dense Structural 72 Structural Lumber except for dense grain requirement. |
| Industrial 65 | Appearance is same as D Finish for thicknesses 4″ and less and widths 12″ and less. Larger sizes conform to Dense Structural 65 Structural Lumber except for dense grain requirement. |
| Grade | Grade Characteristics and Typical Uses |
|---|---|
| See SPIB Special Product Rules for design values | |
| Dense Structural 86 Dense Structural 72 Dense Structural 65 | Premier structural grades. Provides good appearance with some of the highest design values available in any softwood species. |
| Grade | Grade Characteristics and Typical Uses |
|---|---|
| Maximum recommended support spacing is 24″ on center (16″ on center for Imported Southern Pine) | |
| Premium | High-quality product, recommended where smallest knots are desired and appearance is of utmost importance. Excellent for painting or staining. |
| Standard | Slightly less restrictive than premium grade. A very good product to use where a more rustic appearance is desired. Excellent for painting or staining. |
| Grade | Grade Characteristics and Typical Uses |
|---|---|
| Design values are not assigned | |
| *B&B | Highest recognized grade of Finish. Generally clear, although a limited number of pin knots are permitted. Finest quality for natural or stain finish. |
| C | Excellent for painting or natural finish where requirements are less exacting. Reasonably clear, but permits limited number of surface checks and small tight knots. |
| C&Btr | Combination for B&B and C grades; satisfies requirements for high-quality finish. |
| D | Economical, serviceable grade for natural or painted finish. |
| Grade | Grade Characteristics and Typical Uses |
|---|---|
| Design values are not assigned | |
| *B&B, C C&Btr, D | See Finish grades for face side; reverse side wane limitations are lower. |
| No.1 | No.1 Drop Siding is graded as No.1 Boards; No.1 Flooring and Paneling not provided under SPIB Grading Rules as a separate grade, but if specified, will be designated and graded as D. |
| No.2 | Graded as No.2 Boards. High utility value where appearance is not a factor. |
| No.3 | Suitable for economical use as sheathing or lathing. |
| Grade | Grade Characteristics and Typical Uses |
|---|---|
| Design values are not assigned | |
| B&B, C C&Btr, D | Recommended for moulding and millwork applications. |
* Most mills do not manufacture all products and make all grade separations. Those products and grades not manufactured by most mills are noted with an asterisk.
