Can You Make Your Own Clay Bricks?

Bricks made from clay have been around for thousands of years. The first sun-dried mud bricks were used over 10,000 years ago as early as 8000 BCE in areas with little timber, such as Mesopotamia and the Indus Valley. These early bricks were simply mud mixed with straw and molded into shape before being left to dry in the sun.

The Romans introduced more advanced fired clay bricks around 500 BCE. They built brick firing kilns that could fire the bricks at very high temperatures, creating strong, durable bricks. The Romans used bricks extensively in construction, enabling them to build large structures like aqueducts, temples, and amphitheaters. Brickmaking allowed them to standardize sizes and mass produce bricks on an unprecedented scale.

For centuries, handmade, wood-fired clay bricks remained the norm. It wasn’t until the mid 19th century that mechanized brick production began. The Industrial Revolution brought steam-powered brickmaking machines and continuous kilns. Modern brickmaking is highly automated using sophisticated machinery, but some artisans still handcraft bricks using traditional techniques.

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Benefits of Making Your Own Bricks

Making your own clay bricks can provide a number of advantages over purchasing commercially manufactured bricks. Two of the biggest benefits are cost savings and customization.

Homemade bricks cost a fraction of what you would pay at the store. You only need a few inexpensive materials like clay, sand, and water to produce bricks yourself. This allows much more creative freedom and flexibility without worrying about budget constraints.

Since you make the bricks from scratch, you can fully customize the size, color, texture, and shape. Standard bricks have a uniform look, but homemade bricks can incorporate personal touches. You can press objects like coins or shells into the clay to leave behind imprints. Special mixes can create unique colors. The bricks can be molded into custom sizes for small projects or repair work.

Overall, making your own bricks grants far more control over the final product while spending less money. You can create the exact type of bricks you need for every situation.

Choosing the Right Clay

When making your own clay bricks, it’s important to choose the right type of clay. Not all clay is suitable for brick making. Generally, you’ll want a clay that has high amounts of kaolinite. Kaolinite is a type of clay material that provides plasticity and strength when fired, making it ideal for bricks.

The three main types of clay you may encounter are:

Earthenware clays – These fire at lower temperatures but result in weaker, porous bricks.
Stoneware clays – These require higher firing temperatures but produce stronger, more durable bricks.
Porcelain clays – The most refined clays that produce very dense, impermeable bricks.

For brick making, stoneware and porcelain clays are best. You want a clay body that can withstand the high temperatures of firing without deforming.

To test the properties of a clay, take a small sample and roll it into a coil. The coil should be able to support its own weight without drooping. Pinch off a piece and roll it into a ball. The surface should smooth out and not crack. Drop the ball from waist height onto a hard surface. It should deform only slightly but not shatter.

Testing the clay will give you an idea of its plasticity, strength, and workability for brick making. This will ensure you select the most suitable clay for the job.

Preparing the Clay

Once you have sourced some clay, the next step is to prepare it so it has the right consistency for brick making. This involves digging, soaking, and kneading the clay to get it to an ideal state. Here is a more in-depth look at the clay preparation process:

Digging – If you have sourced clay straight from the earth, the first step is to dig it out. Using a shovel, dig down to find the most dense, packed clay deposits. These will have the highest clay content and fewest impurities. Dig out several large chunks of clay to work with.

Soaking – Place the clay chunks in a large tub or barrel filled with water. Let it soak for 1-2 days which allows the clay to fully saturate. This makes the clay more pliable and easier to knead.

Kneading – After soaking, knead the clay thoroughly to mix it evenly and remove any leftover impurities or rocks. Kneading also helps ensure smooth consistency. Do this by hand or with a power mixer. Knead until the clay is completely uniform.

Removing Impurities – Look for any remaining pebbles, rocks, roots or other impurities after kneading. Pull these out by hand to ensure no impurities remain in the clay. You want pure, smooth clay to shape quality bricks.

Once the clay has been soaked, kneaded and impurities removed, it is ready for brick shaping. The clay should be soft, pliable, and smooth at this stage.

Making the Brick Molds

One of the most important steps in creating your own clay bricks is making the molds. The molds will determine the size and shape of your finished bricks. There are a few key considerations when making brick molds:

Mold Materials

The most common materials used for brick molds are wood, steel, aluminum, or plastic. Wood is generally the easiest to work with if you’re making your own molds at home. Opt for a durable hardwood like oak or maple. Make sure the wood is sanded smooth so your bricks release cleanly. Other advantages of wood molds is they are lightweight and less conductive of temperature.

Size Considerations

Standard brick sizes are 8 x 2.5 x 4 inches. But you can make your molds any size you want. Smaller bricks are easier to handle and dry faster. Bigger bricks are stronger but heavier. Consider what you intend to use the bricks for. The mold dimensions will be slightly larger than the final brick size to account for clay shrinkage during drying and firing.

Be sure to make the mold walls thick and sturdy. You want it to withstand repeated pressure and hold its shape. Consider adding supports underneath if making large molds. Also make sure there is a beveled lip for easy brick release.

Shaping the Bricks

Once you have prepared the clay and made your brick molds, the next step is shaping the actual bricks. Start by filling the molds with clay, being sure to pack the clay in tightly to reduce air pockets. Tap the mold on your work surface while filling to help settle the clay.

When the mold is full, use a straight edge to slice off any excess clay on the top, making it flush and smooth. You can also run your finger along the top to smooth it out. The top surface should be flat and level in order to make nice even bricks.

After smoothing the top, turn the mold over onto your work surface and gently remove it, leaving the shaped brick behind. You may need to wiggle or tap the mold to help release the brick cleanly. Repeat this process until all your clay has been shaped into bricks.

Drying the Bricks

Once you’ve shaped your clay bricks, they will need sufficient time to dry before firing. Clay shrinks as it dries, so a slow, controlled drying process is important to prevent cracking. Here are some tips for properly drying your homemade clay bricks:

Allow the shaped bricks to air dry at room temperature for 24-48 hours before moving them. This gives them time to harden slightly so they can be moved without deforming.

Transfer the bricks to drying racks or shelves without stacking them. Stacking can cause uneven drying and cracks. Space the bricks at least 1 inch apart for air circulation.

Allow the bricks to dry for 1-2 weeks. Drying time depends on factors like climate and the size of the bricks. Monitor for cracking and deformities.

Consider using fans or dehumidifiers to speed drying if needed. Just prevent overly fast external drying which causes cracks.

Once the bricks are fully dry with no moisture, they are ready for firing in the kiln.

Firing the Bricks

Once your homemade clay bricks have dried completely, it’s time to fire them in a kiln to harden and finish the bricks. Firing is one of the most important steps in brickmaking, as the right temperature is critical.

For firing clay bricks, you’ll need access to a kiln that can reach fairly high temperatures. Kilns designed for ceramics may only reach around 2000°F, which is typically not enough for firing bricks. Look for a kiln designed specifically for brick firing that can reach temperatures between 2000-2200°F. Gas kilns allow the most precise temperature control.

The firing process should be gradual, with the temperature increasing by no more than 200°F per hour. A slow, controlled firing allows the clay to fully vitrify as it hardens, resulting in a stronger finished brick. Be sure to use pyrometric cones to monitor the temperatures.

The ideal firing temperature depends on the clay composition, but 2000-2200°F is typical. Hold the maximum temperature for 1-3 hours before slowly cooling the kiln. Firing times also depend on the size and quantity of bricks, typically ranging from 24-48 hours total. With proper temperatures and firing time, the clay will vitrify into a hard, durable material perfect for building projects.

Finishing Touches

Once your home made clay bricks have been fired, there are a few finishing touches you can add to improve their appearance and durability:

Cooling

After firing, the bricks will be extremely hot, so allow them to cool completely before handling. This may take 12-24 hours. Rushing the cooling process could lead to cracks or breakage.

Smoothing

If the bricks have rough patches, chips, or uneven surfaces, you can smooth them using sandpaper. Start with a coarse grit sandpaper to remove bigger imperfections. Then use progressively finer grits to achieve a smooth finish.

Sealing

Apply a sealant like tile sealer or concrete sealer to protect the bricks from moisture and stains. This will help them withstand outdoor weather. Apply 2-3 coats as directed on the sealer product. Let each coat dry completely before adding the next.

With these finishing steps, your homemade clay bricks will have a clean, polished appearance and durability for construction projects.

Benefits and Drawbacks

Making your own clay bricks can be a fun and rewarding DIY project. However, it’s important to consider the pros and cons before getting started.

Benefits

Some potential benefits of homemade clay bricks include:

Cost savings – Making your own bricks is generally cheaper than buying commercially manufactured bricks.
Custom options – You can create custom sized bricks and unique colors/textures.
Sustainability – Using local clay is more eco-friendly than buying new bricks.
Satisfaction – It can be fulfilling to create beautiful, handmade bricks.

Drawbacks

Some potential drawbacks to keep in mind include:

Time and labor – Making bricks requires significant time, effort, and physical labor.
Inconsistent quality – Homemade bricks may be less uniform in size, shape and color.
Durability concerns – Handmade bricks may be less durable than commercial bricks.
Firing process – Building and managing a kiln can be technically challenging.

Weighing these factors will help determine if making your own bricks is the right choice for your project.