1st ESO · Technology · Materials Project
An in-depth study of wood — its origins, properties, types, uses, and its relationship with our environment.
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01 — Origin
Wood is a natural material of plant origin. It is found inside the trunks, branches, and roots of trees and shrubs. It forms over many years as the tree grows, adding a new ring of wood each year — these are the famous annual rings you can count on a cut trunk to find out how old the tree was.
From a scientific perspective, wood is composed mainly of cellulose (which gives it flexibility and strength), lignin (which makes it hard and rigid), and hemicellulose. This unique combination of molecules is what gives wood its remarkable range of physical properties.
Humans have used wood for hundreds of thousands of years. The oldest known wooden tools date back over 400,000 years. It was the first material used to build shelters, make fire, create tools, and construct boats — making it arguably the most important material in human history.
02 — Properties
Wood is unique because it combines a very useful set of physical, mechanical, and thermal properties that make it suitable for an enormous variety of applications.
Wood resists compression, bending, and tension very well, especially along the grain. It can bear heavy loads, which is why it is widely used in construction and furniture.
Despite its strength, wood is relatively light. Its density varies greatly by species, but most woods float in water. This makes it ideal when a strong but lightweight material is needed.
Wood is a poor conductor of heat, which makes it a good thermal insulator. Wooden walls and floors keep warmth inside buildings much better than concrete or metal.
Dry wood does not conduct electricity, making it safe to use in situations where electrical insulation is important, such as tool handles.
Wood can be cut, shaped, carved, sanded, drilled, nailed, glued, and painted with relatively simple tools. This workability has made it one of the most versatile materials throughout history.
Wood absorbs and releases moisture depending on the humidity of the environment. This can cause it to swell, shrink, or warp — an important factor to consider in construction and design.
Each piece of wood is unique, with its own grain pattern, colour, and texture. These natural patterns are considered beautiful and are often left visible in furniture and flooring.
Wood burns, which is a disadvantage in construction (fire risk) but an advantage as a fuel source. It ignites at around 300°C, although some treatments can improve fire resistance.
03 — Types
Wood is broadly divided into two main categories based on the type of tree it comes from, and then into many subcategories depending on how it has been processed.
Hardwoods come from deciduous trees — trees that lose their leaves in autumn. Despite the name, not all hardwoods are physically harder than softwoods, but they tend to be denser and more durable.
They grow more slowly, making them more expensive but also more prized for furniture, flooring, and decorative work. Common examples include oak, beech, walnut, cherry, and mahogany.
Softwoods come from coniferous trees — trees that keep their needle-like leaves all year round, such as pine, fir, and cedar. They grow faster, making them cheaper and more widely available.
They are the most used wood in construction (beams, framing, scaffolding) and in making paper and cardboard. Pine is the most common softwood used in Spain.
| Wood Species | Type | Main Characteristics | Common Uses |
|---|---|---|---|
| Oak (Roble) | Hardwood | Very hard, durable, attractive grain, resistant to humidity | Furniture, flooring, wine barrels, construction |
| Pine (Pino) | Softwood | Light, easy to work, affordable, resinous | Construction, furniture, paper, pallets |
| Beech (Haya) | Hardwood | Hard, smooth, good for bending, pale colour | Furniture, tool handles, stairs, toys |
| Walnut (Nogal) | Hardwood | Dark, rich colour, very strong and long-lasting | High-end furniture, decorative work, gunstocks |
| Cedar (Cedro) | Softwood | Aromatic, naturally resistant to insects and moisture | Wardrobes, chests, exterior cladding, pencils |
| Mahogany (Caoba) | Hardwood | Reddish-brown, stable, resists swelling | Luxury furniture, musical instruments, boats |
| Fir (Abeto) | Softwood | Lightweight, straight grain, easy to cut | Construction frames, masts, paper pulp |
Beyond natural solid wood, the industry produces many engineered wood products by transforming and pressing wood fibres, chips, or veneers together with adhesives. These are very common in everyday life.
Made of thin layers of wood veneer glued together with the grain of each layer perpendicular to the next. This makes it strong, stable, and resistant to splitting.
Medium-density fibreboard is made from fine wood fibres and resin pressed under heat. It has a smooth, uniform surface — ideal for painting and detailed work.
Made from wood chips, sawdust, and resin pressed together. Less strong than plywood or MDF but very cheap. Widely used in flat-pack furniture.
Derived from the bark of the cork oak tree. Lightweight, impermeable, and elastic. Used for wine bottle stoppers, flooring, and insulation panels.
Layers of wood glued with the grain aligned. Much stronger than solid wood of the same cross-section, used for large beams and structural arches.
Both are made from wood pulp — wood that has been chemically or mechanically broken down into fibres and then reformed into thin flat sheets.
04 — Uses
Wood is one of the most versatile materials known to humanity. Its applications span almost every area of daily life and industry.
Wooden beams, frames, roofing structures, floor boards, doors, and window frames. In many countries, entire houses are built primarily from wood.
Tables, chairs, wardrobes, beds, shelves — furniture is one of the most traditional and important uses of wood, from the simplest pine shelf to the finest walnut cabinet.
Nearly all paper and cardboard is made from wood pulp. This includes books, notebooks, newspapers, cardboard boxes, and packaging materials.
Guitars, violins, pianos, drums, flutes — the acoustic properties of different types of wood make it the preferred material for most musical instruments.
Wood is still one of the most important fuels worldwide. It is burned directly as firewood or transformed into charcoal, wood pellets, and biomass for heating and electricity generation.
Historically used for ships, carts, and railway sleepers. Today it is still used for boat building, rail infrastructure, and some specialist vehicles and aircraft.
Skateboards, baseball bats, cricket bats, chess pieces, toys, and playground equipment. Wood's combination of strength, flexibility, and feel makes it ideal for sports goods.
Some textile fibres, such as viscose (rayon) and lyocell (Tencel), are derived from wood pulp. These are soft, breathable fabrics used in clothing.
05 — Processing
Before wood can be used as a material, it goes through a series of important processes. Understanding these steps helps us appreciate both the value of the material and its environmental cost.
Trees are cut down in the forest — ideally in managed forests where replanting is guaranteed. The logs are then transported to a sawmill by truck, train, or river.
At the sawmill, the logs are cut into planks, beams, or boards of standard sizes using large industrial saws. The shape of the cut affects the strength and appearance of the final plank.
Freshly cut wood contains a large amount of water (up to 50% of its weight). It must be dried — either naturally in the open air for months, or artificially in a kiln — to reduce the moisture content and prevent warping, cracking, and decay.
The dried planks are sorted by quality, size, and species. Higher-grade wood (with fewer knots and defects) is used for visible surfaces and high-quality furniture; lower grades go to structural or hidden uses.
Wood may be treated with preservatives to protect against insects, fungi, and moisture. Then it can be planed smooth, sanded, stained, varnished, painted, or oiled depending on its final use.
The processed wood is sold to carpenters, builders, manufacturers, and retailers who transform it into final products — from a handmade chair to a house frame.
| Tool | Purpose | Type |
|---|---|---|
| Hand saw (Sierra de mano) | Cutting wood to length or shape | Manual / Power |
| Plane (Cepillo) | Smoothing and levelling flat surfaces | Manual / Power |
| Chisel (Formón) | Cutting joints, mortises, and detailed shaping | Manual |
| Drill (Taladro) | Making holes of various diameters | Power |
| Sander (Lijadora) | Smoothing surfaces before finishing | Manual / Power |
| Router (Fresadora) | Cutting grooves, profiles, and decorative edges | Power |
| Lathe (Torno) | Shaping cylindrical pieces by rotation | Power |
| Clamp (Prensa/Mordaza) | Holding pieces together while glue dries | Manual |
06 — Environment
Wood is one of the few truly renewable materials — but only when forests are managed responsibly. Its relationship with the environment is complex and deeply important.
Trees absorb carbon dioxide (CO2) from the atmosphere as they grow, storing carbon in their wood. When we use wood in long-lasting products like furniture or buildings, that carbon remains locked away for decades or centuries. This makes wood a carbon store, helping to reduce the greenhouse effect.
Compared to materials like concrete, steel, or plastic, the production of wood requires far less energy and releases far fewer greenhouse gases. Replacing these materials with wood in construction is one strategy for reducing a building's carbon footprint.
Deforestation is one of the biggest environmental problems linked to wood. When forests are cut down faster than they can regrow — as is happening in the Amazon, in Southeast Asia, and parts of Africa — the result is a catastrophic loss of biodiversity, disruption of water cycles, and release of stored carbon into the atmosphere.
Illegal logging, conversion of forests to farmland, and poorly managed timber industries all contribute to this problem. It is estimated that around 15 billion trees are cut down each year worldwide.
Using less wood by designing products that require fewer materials, avoiding waste during cutting and shaping, and choosing longer-lasting products over disposable ones.
Old furniture, beams, and floorboards can be given new life. Reclaimed wood (madera de recuperación) is popular in interior design and is a very sustainable choice.
Wood waste and sawdust can be recycled into chipboard, paper pulp, or used as biomass fuel. Paper and cardboard should always be recycled in the blue bin.
Video Script
Below is a complete script for the video presentation accompanying this project. It covers all the key topics in a concise, clear, and engaging way — suitable for recording as a narration over images or as a direct-to-camera presentation.
Estimated duration: 4–5 minutes
Hello. In this video I am going to talk about wood — one of the oldest and most important materials that humans have ever used. Wood comes from trees, it is completely natural, and it has been part of our lives for hundreds of thousands of years. From the first shelters to modern buildings, from ancient boats to today's furniture, wood is everywhere. Let's explore where it comes from, what makes it special, and how we can use it responsibly.
Wood is found inside the trunks, branches, and roots of trees and shrubs. If you look at a cross-section of a tree trunk, you can see several layers. The outermost layer is the bark, which protects the tree. Just inside is the cambium — a thin ring of living cells that produces new wood each year. These annual rings are what lets us calculate the age of a tree. Closer to the centre is the sapwood, which carries water and minerals up the trunk. And at the very heart is the heartwood — the densest, darkest, and most durable part. Wood is made mostly of cellulose, which gives it flexibility, and lignin, which makes it hard and rigid.
Wood has a remarkable set of properties. It is mechanically strong — it can support large loads without breaking. It is relatively light, especially compared to metals or concrete. It is a good thermal insulator, which means it keeps heat in, making it ideal for building warm homes. It does not conduct electricity, which makes it safe for many applications. It is also easy to work with — you can cut it, shape it, sand it, nail it, glue it, and paint it. However, wood does have some disadvantages: it burns, it can absorb moisture and warp, and it can be attacked by insects and fungi if not properly treated.
There are two main categories of wood. Hardwoods come from deciduous trees — trees that lose their leaves in autumn, like oak, beech, and walnut. They are generally denser, more durable, and more attractive, which is why they are used for high-quality furniture and flooring. Softwoods come from coniferous trees — trees with needles, like pine and fir. They grow faster, so they are cheaper and more widely available. Softwoods are the most used wood in construction and for making paper. Beyond solid wood, there are also derived products like plywood, MDF, and chipboard — all made by pressing together wood fibres or chips with adhesives to create flat boards used in furniture and construction.
The uses of wood are almost endless. In construction, it is used for beams, floors, doors, and windows — and in many countries, entire houses are built from wood. In furniture, it is used for tables, chairs, beds, and wardrobes. Almost all paper and cardboard comes from wood pulp. Wood is also essential for musical instruments — guitars, violins, and pianos all rely on the acoustic properties of specific types of wood. It is used in sports equipment, toys, boats, and even to produce textile fibres like viscose. And of course, wood is still an important fuel — burned directly or converted into pellets and charcoal for heating and energy.
Before we can use wood, it must be processed. First, trees are felled in the forest and transported to a sawmill. There, they are cut into planks and beams. The freshly cut wood contains a lot of water, so it must be dried — either naturally or in a kiln — before it can be used. After drying, the wood is sorted by quality and size. Finally, it may be treated with preservatives to protect against moisture and insects, then sanded, varnished, painted, or oiled depending on its final use.
Wood has an important relationship with our environment. On the positive side, trees absorb carbon dioxide from the atmosphere, and when we use wood in long-lasting products, that carbon stays locked away for decades. Wood also requires much less energy to produce than steel or concrete. However, deforestation — cutting down forests faster than they grow back — is one of the most serious environmental problems in the world today. Billions of trees are lost every year, causing habitat destruction and releasing carbon into the atmosphere. The solution is sustainable forestry: managed forests where trees are replanted after being cut. When buying wood products, look for the FSC or PEFC certification labels, which guarantee the wood comes from a responsibly managed source. And remember the three Rs: reduce wood waste, reuse old wood and furniture, and recycle paper and cardboard.
Wood is one of the most extraordinary materials that nature gives us. It is strong, light, beautiful, and — when managed well — completely renewable. From the forests of Murcia to the furniture in our homes, wood is a part of daily life that we often take for granted. By understanding this material better and using it responsibly, we can continue to benefit from it for generations to come. Thank you for watching.