Understanding 5/4 Lumber: Actual Size, Uses, and More

Understanding 5/4 Lumber: Actual Size, Uses, and More

In the world of woodworking, understanding the different types of lumber is essential.

Whether you’re a seasoned craftsman or a beginner, you’ve probably come across the term “5/4 lumber.”

But what exactly does it mean? In this comprehensive guide, we’ll delve into the details of 5/4 lumber, including its actual size, common uses, and more. So, let’s jump right in!

What is 5/4 Lumber?

When you’re shopping for lumber, you may notice that the dimensions listed don’t always match the actual size of the board.

This is because wood is sold according to nominal measurements, which can be different from the actual measurements.

5/4 lumber is a pre-cut of lumber commonly used in woodworking projects. However, its thickness is not actually 5/4 inches, but rather 1.25 inches.

Understanding Lumber Thickness

To fully grasp the concept of 5/4 lumber, it’s important to understand how the thickness of wood is measured.

Softwoods, such as pine, are typically sold in conventional dimensions. However, hardwoods are often sold by the board foot, which is a volume unit equal to approximately 144 cubic inches.

Hardwoods can also be sold in quarters, with each quarter being equivalent to 1/4 inch. Therefore, 5/4 lumber is one and a quarter inches thick.

Measuring the Thickness of 5/4 Lumber

It’s worth noting that the thickness of a 5/4 board may vary slightly depending on the surfacing process.

Before starting your woodworking project, it’s recommended to measure the actual thickness of the hardwood board, as some material may be lost during planning.

In general, 5/4 lumber typically ends up with a finished thickness of around 1.063 inches.

Different Names for 5/4 Lumber

The terminology used to refer to 5/4 lumber may vary depending on the location or profession.

However, there are two universally recognized terms: “Five-Fourths Lumber” and “Five-Quarters Lumber.”

Both terms are interchangeable and widely understood within the woodworking community.

Spanning Capabilities of 5/4 Deck Boards

5/4 lumber is commonly used in decking projects. When it comes to the maximum span of a 5/4 deck board, it’s important to consider the distance between the joists.

For 5/4 decking boards, the joists should not be spaced further than 16 inches apart.

However, decks made with 2 x 4 or 2 x 6 boards can have joists spaced up to 24 inches apart.

If the decking runs at an angle, it may be necessary to place the joists closer together for added support.

Understanding the Quarter System

The quarter system is a method of measuring the thickness of rough-sawn lumber. Rather than being read as a fraction, it is read as several quarters.

For example, 5/4 lumber is equivalent to five quarters, 4/4 lumber is equal to four quarters, and so on. The thickness of a 5/4 board is 1.25 inches since it is five quarters.

It’s important to note that the quarter system is primarily used to measure rough stock.

Once the boards are surfaced, the actual thickness measurements are typically used.

For example, a board that is 6/4 when rough-sawn would be referred to as 1.5 inches thick after surfacing, assuming the standard 1/4 inch of material was lost during planning.

Common Uses of 5/4 Lumber

Hardwood lumber, such as 5/4 boards, is a favored material for various woodworking projects due to its appearance and durability.

It is commonly used in furniture making, musical instrument construction, boat building, and home flooring.

Different species of hardwood lend themselves well to specific projects, providing a wide range of options for craftsmen.

For decking projects, 5/4 lumber is a popular choice. It is economical and easy to work with, making it a go-to material for decks in North America.

Additionally, using 5/4 boards for decking is considered more environmentally friendly since it requires fewer trees to be cut down compared to using larger boards.

When it comes to specific types of hardwood lumber for decking, 5/4 mahogany boards are highly sought after.

Mahogany is known for its exceptional durability, natural resistance to warping, and resilience against insect damage.

While mahogany may be slightly more expensive, a deck built with 5/4 mahogany boards is likely to last for many decades.

Choosing the Right Lumber for Decking

When selecting lumber for your deck, there are two main types to consider: pressure-treated lumber and naturally resistant lumber.

1. Pressure-treated Deck Lumber: Made of pine or fir, pressure-treated lumber is infused with chemicals that make it highly resistant to rot. It often has a green or brown appearance, but this can be hidden with paint or stain. Pressure-treated lumber is cost-effective and readily available, making it a popular choice for decking frames.
2. Naturally Resistant Deck Lumber: Softwood species like cedar, cypress, and redwood are naturally resistant to rot and insects, particularly the heartwood found in the center of the tree. These woods can be sealed or stained to preserve their natural beauty or allowed to weather to a grayish hue. Exotic hardwood species like cambara, meranti, and ipe are also durable options, but they can be more expensive and harder to work with.

Understanding S4S Boards

When shopping for lumber at home centers or lumberyards, you may come across the term “S4S,” which stands for “Surfaced Four Sides.”

S4S boards are hardwood and softwood lumbers that have been milled on all four sides to specific dimensions. These boards are typically sold by the linear foot.

For example, a board labeled as 1 x 6 inches actually measures 3/4 inches thick and 5 1/2 inches wide.

The price of S4S boards includes the cost of milling and labor.

However, it’s important to note that not all lumber sold by the board foot goes through the same milling process, so you may end up with more wood than expected.

Understanding Lumber Thickness Measurements

Hardwood lumber thickness is typically measured in quarters of an inch. For example, 4/4 lumber is 1 inch thick when rough-sawn and approximately 13/16 inches thick after planing.

The thickness you pay for is the rough-sawn measurement, but the thickness after planing may be slightly smaller, usually around 3/4 inches.

Here’s a summary of typical hardwood lumber thicknesses before and after planing:

FAQs – 5/4 Lumber

Q: What lumber is best for decking frames? A: Pressure-treated lumber is generally the best choice for decking frames due to its cost-effectiveness and resistance to rot.

Q: What are the four types of lumber for woodworking? A: The four primary types of wood used in woodworking are hardwood, softwood, plywood, and MDF (medium-density fiberboard).

Q: What is a board foot? A: A board foot is a unit of measurement used to determine the volume of wood. It is calculated by multiplying the thickness, width, and length of a board and then dividing by 12.

Conclusion

Understanding 5/4 lumber is crucial for any woodworking enthusiast. By knowing its actual size, common uses, and how it fits into the quarter system, you can confidently select the right lumber for your projects.

Whether you’re building furniture or decking, 5/4 lumber offers a versatile and durable option. So, next time you’re in the lumber aisle, you’ll be well-equipped to make informed decisions and create beautiful woodworking masterpieces.