Name: wood grain in softwoods and hardwoods
Uploaded: 2024-09-12T16:16:32.000Z
Duration: 1 min 28 s
Channel: JoVE

Most cone-bearing trees have needle-like leaves and are classified as softwoods, and most hardwood trees have broad leaves that are shed on a seasonal basis.
Softwood&#39;s microstructure comprises large longitudinal cells known as tracheids and a minor proportion of radial cells called rays.
Construction elements, such as structural frames, sheathing, roofing materials, and exterior siding, use softwoods.
Cell fibers and cavities hold moisture in living or newly cut wood. As drying begins, cavity water evaporates, leaving residual water in fibers, causing the wood to shrink.
The stage at which wood shrinks is called the fiber saturation point. At this stage, most softwoods contain around 30 percent moisture.
Hardwood trees have a higher percentage of rays and two distinct types of longitudinal cells: small-diameter fibers and large-diameter vessels.
Hardwoods are used for furniture, door and window frames, interior trim, and floor installations.
Softwoods, when processed into timber, display a rough, simple grain structure, whereas hardwoods often exhibit finer, intricate grain patterns valued for aesthetics.

softwoods and hardwoods

Softwoods and hardwoods, derived from different types of trees, are distinguished by their leaf structures and cellular compositions, each serving unique purposes in construction and manufacturing. Softwoods come from cone-bearing trees with needle-like leaves and are predominantly composed of longitudinal cells called tracheids and a smaller proportion of radial cells known as rays. Due to their cellular structure, softwoods are commonly used in construction for structural frames, sheathing, roofing materials, and exterior siding.
The moisture content in softwoods plays a critical role in their use. In living or newly cut wood, cell fibers, and cavities retain moisture. As the wood dries, the water in the cavities evaporates first, followed by the residual water in the fibers, causing the wood to shrink at what is known as the fiber saturation point, typically around 30 percent moisture for most softwoods.
Hardwoods, on the other hand, typically shed their broad leaves seasonally and have a more complex microstructure with a higher percentage of rays and two types of longitudinal cells: small-diameter fibers and large-diameter vessels or pores. This complex structure makes hardwoods suitable for making cabinets, furniture, paneling, interior decorative trim, and flooring. The grain of hardwoods is often finer and more intricate, making it visually appealing and highly valued for aesthetic purposes. In contrast, softwoods generally exhibit a rougher and simpler grain structure.

Softwoods and Hardwoods

Most cone-bearing trees have needle-like leaves and are classified as softwoods, and most hardwood trees have broad leaves that are shed on a seasonal ...

Education

JoVE Core

Civil Engineering

Unit 1

Wood

KEY TERMS AND CONCEPTS

wood grain in softwoods and hardwoods

Softwoods and hardwoods come from different kinds of trees, and their leaf structures and cell makeup help explain how they are used. Softwoods come from cone-bearing trees with needle-like leaves. Hardwoods usually come from trees that shed broad leaves seasonally.

Softwoods are made mostly of long cells called tracheids and a smaller number of rays, which are radial cells. This simpler structure gives softwoods a rougher grain. Because of this, they are often used in construction for structural frames, sheathing, roofing materials, and exterior siding.

Moisture content is also important in softwoods. In living wood or newly cut wood, moisture remains in the cell fibers and cavities. As the wood dries, water leaves the cavities first and then the fibers. Shrinkage begins at the fiber saturation point, which is typically around 30 percent moisture for most softwoods.

Hardwoods have a more complex microstructure. They contain a higher percentage of rays and two kinds of longitudinal cells: small-diameter fibers and large-diameter vessels, also called pores. This structure gives hardwoods a finer, more intricate grain, which makes them useful for cabinets, furniture, paneling, interior decorative trim, and flooring. Their appearance is often valued for its aesthetic appeal.

Wood Grain in Softwoods and Hardwoods

introduction to wood

Wood Structure and Uses in Building

Wood is a construction material made from trees. A tree trunk has several layers. The outside is a protective layer of dead bark. Under that is living bark, then the cambium, then sapwood. As sapwood matures, it becomes heartwood. The pith sits at the center of the trunk. The age of a tree can be read from its growth rings. These rings are concentric bands seen in a trunk cross-section. Wood strength also depends on grain. Grain refers to elongated, tubular cells that run along the length of...

Softwoods and hardwoods come from different kinds of trees, and their leaf structures and cell makeup help explain how they are used. Softwoods come from cone-bearing trees with needle-like leaves. Hardwoods usually come from trees that shed broad leaves seasonally. Softwoods are made mostly of long cells called tracheids and a smaller number of rays, which are radial cells. This simpler structure gives softwoods a rougher grain. Because of this, they are often used in construction for...

lumber

Lumber Cutting Methods

Lumber is made from logs that are harvested, debarked, and processed into long pieces with a rectangular cross-section. The process starts when an automated saw slices a log into slabs. Those slabs then move on a conveyor belt to smaller saws, where they are cut into square-edged pieces of specific widths. Freshly cut lumber usually has rough surfaces. Its dimensions may also vary slightly from one end to the other. The way wood is cut affects both the lumber’s appearance and how it is used. <br...

structural properties and dimensions of lumber

structural-properties-and-dimensions-of-lumber

Wood Strength Tests and Lumber Sizes

Wood strength depends on how its fibers are aligned along the length of the tree. This alignment gives wood much greater tensile strength along the grain than across it, sometimes up to twenty times higher. Wood also tends to perform better under compression than under tension. Fiber length varies by wood type. Hardwoods have fibers about one twenty-fifth of an inch long. Softwoods have longer fibers that range from one-eighth to one-third of an inch. Laboratory tests help measure how wood...

seasoning of wood

Wood Drying for Stronger Construction

Seasoning of wood is the drying process used to lower and stabilize moisture content before wood is used in construction. Fresh wood can swell when it takes in moisture and contract as it dries. Seasoning helps reduce that movement so the wood stays more stable after it is built into a structure. The main goal is to reach equilibrium moisture content. This is the point where the wood’s moisture level matches the moisture in the surrounding environment. When wood is seasoned properly, it is...

wood surfacing

Wood Surfacing for Smooth, Safe Lumber

Wood surfacing smooths lumber, improves its size accuracy, and makes it safer to handle. It is a key finishing step in woodworking and construction. The process also helps correct small distortions that can form as wood dries. Before surfacing, the wood may be sized slightly larger to account for shrinkage during seasoning, which is the drying stage. A plane, a tool with rotating blades, is used to remove material and smooth the surface. The same tool can also round the edges a little, which...

lumber defects

Common Wood Flaws in Lumber

Lumber defects are flaws in wood that can change both its appearance and its strength. These defects come from tree growth and from the way lumber is processed. Knowing the main defects helps explain why some boards are better for construction and manufacturing than others. Some defects begin in the tree itself. Knots form where branches were once attached to the trunk, and knotholes appear when those knots fall out. Decay and insect damage are also natural defects that can weaken wood and...

wood fasteners

Wood Fastener Types and Uses

Wood fasteners connect parts of a wood structure and help keep members in place. The strength of the connection depends mainly on direct bearing between the wood members. Different fasteners are chosen for different jobs and structural needs. Nails are the most common wood fasteners. They are sharp-pointed metal pins that are driven into wood with a hammer or a mechanical nail gun. Nails come in many diameters, head styles, and lengths. Nailing methods also matter. Face nailing places the...

veneer

How Veneer Is Cut and Used

Veneer is a thin sheet of wood that is usually about one-eighth of an inch thick or less. It is made to show the look of wood while using timber more efficiently. Veneer is common in furniture and other finished wood products. One common way to make veneer is rotary cutting. In this method, a log is mounted in a large lathe and spun against a knife edge. As the knife moves deeper into the turning log, it peels off a continuous strip of wood. This creates rotary-cut veneer. Other veneer...

wood products

Engineered Wood Products in Construction

Engineered wood products are made from wood strands, veneers, lumber, and even waste wood shreds. They are used in both structural and nonstructural building applications. These materials are designed to improve strength, durability, and versatility in modern construction. Glue-laminated wood, or glulam, is made by bonding several smaller pieces of dimensional lumber with adhesive. Cross-laminated timber uses solid lumber panels with layers placed so the grain direction alternates. This layer...

wood panel products

Types of Wood Panels in Construction

Wood panels are common construction materials used for flooring, siding, and roofing. They usually come in standard 4-foot by 8-foot sheets. Their thickness can range from one-quarter of an inch to one and one-eighth inches. Plywood is one of the most familiar wood panels. It is made by gluing thin wood veneers, or layers, under pressure. The outer veneer grain runs lengthwise, while the inner layers run widthwise. Plywood also has an odd number of layers, which helps keep the panel...

key terms and concepts

Compare softwoods and hardwoods by tree type, cell structure, grain, moisture loss, and common uses in construction, furniture, and flooring.

Wood Grain in Softwoods and Hardwoods | JoVE K12

JoVE Core Civil Engineering offers a foundational exploration of essential construction materials such as bricks, stones, steel, wood, and concrete, along with fluid mechanics topics like flow over immersed bodies, open channel flow, and dimensional modeling. It also covers key surveying concepts, including leveling, traverse adjustments, curve design, topographic mapping, and geospatial technologies (GPS & GIS). Science-in-action videos showcase laboratory research on materials, fluids, and surveying practices in real-world engineering systems.

civil engineering

Wood Grain in Softwoods and Hardwoods

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