Sustainable Building Sourcebook
Chapter: Materials
 
Finger-Jointed Wood
 
CSI Numbers: 06062 Lumber
 
Introduction:
 

Finger-jointed studs use short pieces of 2x dimensional lumber material glued together to form standard length studs. While they may be manufactured in any species, products are most commonly available in:

  • Douglas Fir-Larch
  • Hem-Fir
  • Spruce-Pine-Fir (South)
  • Western Woods

The grades of structural end- or finger-jointed lumber produced include:

  • STUD
  • SELECT STRUCTURAL
  • No. 1
  • No. 2
  • STANDARD & BETTER

STUD and No. 2 & BTR are the most widely available of these grades.

Specifying finger-jointed lumber reduces the use of solid sawn lumber. Moreover, solid sawn studs may have weak spots and may twist and warp. The builder usually ends up having to replace a lot of solid lumber studs, thus increasing construction costs. Finger-jointed studs are resource-efficient engineered materials, which are as strong as, but straighter and more stable than solid-sawn studs. This radically reduces the need to cull bad studs, normally required with solid-sawn studs. This saves material, time and money.

 
At-A-Glance Notes:
 
Technology:
The use of finger-jointed studs and lumber is widely practiced and accepted.
 
Suppliers:
Finger-jointed studs in short lengths (pre-cut to 12') are stocked at many building supply and lumber retail stores. Long lengths usually have to be ordered. Finger-jointed casing is available at home improvement centers.
 
Cost:
The cost is the same as solid-sawn dimensional lumber.
 
Public Acceptance:
Accepted.
 
Regulatory:

Structural-glued lumber is referenced by all model building codes and numerous standards-writing agencies including the following:

  • 2000 International Building Code (published by International Code Council) Section 2303.1.1
  • 2000 International Residential Code for One- and Two-Family Dwellings (published by International Code Council) contains three separate references:

Floor Framing, Section R502.1.3

Wall Framing, Section R602.1.1

Roof Framing, Section R802.1.2

 
Considerations:
 

Structural graded products (see Guidelines below) range in size from 2x2 through 2x12 with the bulk of production being in 2x4, 2x6, 2x8, and 2x10, and in any length. Extra-long lengths are often available. Long lengths, up to 32' or more, are one of the distinct advantages of structural-glued finger-jointed products. Vertical use graded (see Guidelines below) finger-jointed lumber production is limited to 2x2 through 2x6, with lengths limited to 12 feet.

 
Guidelines:
 

Use finger-jointed studs (graded equivalent to full dimensional studs --1997 UBC Standard, Chapters 23 and 35) wherever conventional studs are typically used, in structural and vertical applications (see below). Use of finger-jointed studs may require code approval by your local jurisdiction and may need to be submitted to the structural engineer of record for approval.

Structural finger-jointed lumber is manufactured to meet the requirements of two different types of end-use applications. The first category is basically an all-purpose product, indicated by CERT EXT JNTS on the grade stamp. The second category is appropriate for use where the primary loading will be in compression parallel-to-grain, indicated by VERTICAL USE ONLY on the grade stamp. Both of these applications are described below.

Structural Applications

Finger-jointed products grade stamped CERT EXT JNTS are intended for all structural applications. This lumber is assembled with a waterproof, exterior-type adhesive. Limitations on knot size and placement near joints are highly restrictive. CERT EXT JNTS stamped products may be used interchangeably with any solid-sawn lumber product of the same species and grades. The lumber may be used as beams, joists, rafters, studs, plates, or in any other exterior or interior framing application.

Vertical Applications

Products that are grade stamped VERTICAL USE ONLY (previously stamped and known as STUD USE ONLY ) are appropriate for carrying loads in compression as vertical framing members. VERTICAL USE ONLY stamped finger-jointed lumber is manufactured to meet the performance capabilities of solid sawn, end-loaded bearing members where short-term bending or tension loads from lateral forces such as wind, seismic and impact may be present, but where forces from the conditions of long-term, sustained-bending or tension loading are not present.

These products are typically assembled with a water-resistant adhesive (indicated on the grade stamp as CERT GLUED JNTS ). VERTICAL USE ONLY products indicated as CERT GLUED JNTS are limited to conditions where the glued joint will not be exposed to prolonged and/or frequent moisture, and where the moisture content of the wood will not exceed 19% in use. The term VERTICAL USE ONLY is recognized in daily selling conversation. CERT GLUED JNTS is not typically referenced.

 
Resources:
 
Components/Materials/Systems:

Generally available at most lumber retailers, see "Lumber-Retail" and "Lumber-Wholesale" in Yellow Pages

Austin Lumber Company
2415 E. 5th St
Austin, TX 78702
(512) 476-5534
Local supplier of certified sustainable wood

BMC West Building Materials
3400 Steck Ave.
Austin, TX
(512) 465-4200
www.bmcwest.com
Stocks standard 2x stud sizes and can order non-standard lengths and sizes

Breco Wood Products, Inc.
620 E. Pecan St.
Sherman, Texas 75090
(903) 868-1541
www.brecowoodproducts.com
Finger-jointed lumber wholesaler
 
General Assistance:

Southern Forest Products Association (PDF)

Universal Forest Products (PDF)

Wood Promotion Network