Wooden Plank Sizes in Construction in USA

Standard Wooden Plank Sizes in U.S. Construction Projects

In the construction industry in the USA, the use of wooden planks is a foundational component in both residential and commercial structures. The sizes of wooden planks used across the country adhere to standardized measurements for efficiency, compatibility, and safety in all phases of construction. These planks are available in nominal and actual dimensions, with varying thicknesses, widths, and lengths, tailored to suit specific applications including framing, flooring, decking, and paneling.

The most common nominal sizes of wooden planks used in U.S. construction are:

• 1×4, 1×6, 1×8, 1×10, 1×12
• 2×4, 2×6, 2×8, 2×10, 2×12
• 4×4, 4×6, 6×6

These nominal sizes refer to lumber dimensions before surfacing, and the actual dimensions are typically reduced due to the milling process.

Nominal vs Actual Dimensions

The discrepancy between nominal size and actual size is critical in planning construction projects. Below are the typical actual dimensions for commonly used planks:

• 1×4: 0.75 in x 3.5 in
• 1×6: 0.75 in x 5.5 in
• 2×4: 1.5 in x 3.5 in
• 2×6: 1.5 in x 5.5 in
• 4×4: 3.5 in x 3.5 in
• 6×6: 5.5 in x 5.5 in

Length varies by application and is typically available in 8, 10, 12, 14, 16, and 20 feet.

Types of Wooden Planks by Application

Framing Lumber

2×4, 2×6, and 2×8 planks are primarily used in wall framing, floor joists, and roof rafters. These planks are typically made from:

• Douglas Fir
• Southern Yellow Pine
• Hem-Fir

Their structural strength and dimensional stability make them suitable for load-bearing walls and subfloor assemblies.

Decking Planks

Outdoor decking requires planks that are pressure-treated, weather-resistant, and structurally durable. Common sizes include:

• 5/4×6 actual: 1 in x 5.5 in
• 2×6 actual: 1.5 in x 5.5 in

Popular species for decking include:

• Western Red Cedar
• Redwood
• Pressure-treated Pine
• Composite lumber alternatives

Flooring and Paneling

Interior wooden planks used for flooring or wall paneling often come in tongue-and-groove or shiplap formats, in sizes such as:

• 1×4, 1×6, and 1×8
• 3/4 inch thick hardwood planks

Hardwood varieties include:

• Oak
• Maple
• Hickory
• Walnut

These woods are selected for their durability, grain aesthetics, and long lifespan.

Dimensional Lumber Grades and Standards

Wooden planks in the U.S. adhere to grading systems established by organizations such as:

• American Lumber Standard Committee (ALSC)
• National Hardwood Lumber Association (NHLA)
• Southern Pine Inspection Bureau (SPIB)

Grades determine the suitability of planks for structural, non-structural, or appearance-focused applications. Common softwood grades include:

• #1 Structural
• #2 Common
• #3 Utility

Hardwood is graded by appearance, with grades such as:

• FAS (First and Seconds)
• Select
• #1 Common
• #2 Common

Pressure-Treated vs Untreated Planks

For exterior or moisture-exposed areas, pressure-treated planks are used extensively. These are infused with chemical preservatives to resist:

• Rot
• Fungal decay
• Termite infestation

Common treatments include:

• ACQ (Alkaline Copper Quaternary)
• CA (Copper Azole)

Pressure-treated planks are typically marked with stamps indicating treatment type, retention level, and approved use (above ground or ground contact).

Engineered Wood Plank Sizes

In modern U.S. construction, engineered wood is favored for its dimensional stability, cost-efficiency, and sustainability. Key products include:

• LVL (Laminated Veneer Lumber) – sizes: 1 ¾ in thickness, widths up to 24 in, and lengths up to 60 ft
• OSB (Oriented Strand Board) – standard size: 4 ft x 8 ft, thickness: 7/16 in to 1 1/8 in
• Plywood – available in grades A-D, sizes: 4 ft x 8 ft, thicknesses: 1/4 in to 1 1/8 in

These engineered planks are widely used in subfloors, sheathing, headers, and rim joists.

Sourcing Wooden Planks in the U.S. Market

Major suppliers of wooden planks across the United States include:

• Home Depot
• Lowe’s
• Menards
• 84 Lumber
• Builders FirstSource

These suppliers offer planks in bulk, pre-cut sizes, and custom lengths for project-specific demands. Planks are available in kiln-dried, green, and air-dried forms.

Moisture Content and Its Impact on Plank Size

Moisture content plays a vital role in dimensional stability. U.S. construction standards require:

• 19% or lower moisture content for framing lumber
• 6% to 9% for interior hardwood flooring

Lumber is categorized as:

• S-GRN (Surface Green)
• S-DRY (Surface Dry)
• KD (Kiln-Dried)

Kiln-drying reduces warping, shrinkage, and splitting, ensuring structural integrity and finish quality.

Regional Preferences and Availability

Plank sizes and wood species may vary by region due to climatic conditions, local forestry resources, and building practices:

• West Coast: Douglas Fir, Redwood
• South: Southern Yellow Pine
• Northeast: Eastern White Pine, Maple
• Midwest: Oak, Poplar

Builders often select species and sizes based on load-bearing needs, resistance to moisture, and local code compliance.

Cost Considerations by Size and Grade

Pricing of wooden planks in the U.S. is determined by:

• Dimensions (thicker and longer planks cost more)
• Grade (appearance and structural capacity)
• Treatment (pressure-treated lumber is more expensive)
• Market conditions (supply chain and seasonal demand)

As of 2025, average price ranges per linear foot are:

• 2×4 untreated pine: $0.75 – $1.25
• 2×6 pressure-treated: $1.50 – $2.75
• 1×6 red oak: $2.00 – $3.50
• Engineered LVL beam: $3.50 – $5.50 per foot

Conclusion

The availability and use of wooden plank sizes in construction in USA is shaped by standardized dimensions, structural requirements, environmental factors, and regional preferences. Understanding nominal vs actual dimensions, wood species, grading systems, and treatment methods allows contractors and builders to select the most appropriate plank for every application. Whether it’s framing a load-bearing wall, installing durable flooring, or constructing weather-resistant decking, the precision in choosing the right wooden plank size ensures durability, safety, and aesthetic value in every American construction project.