Everything You Need to Know

A building’s strength is based on the building material used to construct it, so choosing the right material is critical for a successful project. For many construction companies, the choice is between compressed earth blocks vs. bricks vs. concrete. As providers of brick and block making machines for over 30 years, our team at Lontto has stepped in to help you decide which pressed blocks you should choose.

We've distilled our decades of knowledge into easy-to-understand strengths and weaknesses for each type of material, but we’ve also included some more technical specifications. Whether it's for sustainable building or your next masonry project, you'll be able to find all the information you need to know right here.

Key Takeaways:

  • Compressed earth bricks (CEBs) are cost-effective and eco-friendly, around 40% cheaper than bricks and concrete, and are made from local materials with lower energy requirements.
  • CEBs are low-carbon but less durable, bricks offer aesthetic appeal but are costly, and concrete is strong but has sound and moisture issues.
  • CEB production involves mixing soil, sand, and cement, then compacting and curing with a machine, ensuring strength and a low carbon footprint.
  • Ideal for sustainable projects, CEBs are versatile and suitable for both residential and (small-scale) commercial construction.

What are Compressed Earth Blocks?

what are compressed earth blocks types of compressed earth blocks

Compressed earth blocks (CEBs) are a type of building material that made from locally sourced ingredients, usually consisting of soil, clay, sand, and a stabilizing agent. They are a reliable cost-saver for many companies since you can use earthen materials on-site, saving on material and transportation costs. In fact, CEBs are around 40% cheaper than fired bricks or concrete blocks thanks to the energy and logistical costs you end up saving.

As a construction material, CEBs are also the most environmentally friendly option when compared to bricks and concrete. Almost 65% of all soil is useful for compressed earth block construction projects, which means you can fire up CEBs all over the world, from Colorado to Ghana. Earth bricks also require far less energy to manufacture — simply letting them dry naturally in the sun and the wind is enough to create the building blocks of your project. However, it’s worth noting that unstabilized CEBs can be air-dried, but stabilized CEBs (with cement) require curing.

CEBs vs. Bricks vs. Concrete: Key Differences

We’ve summarized the key difference between these materials in the table below:

Compressed Earth Blocks Bricks Concrete
Strengths Cost-effective, low embodied carbon footprint Thermal mass resistance, aesthetic appeal Mass production, load-bearing capabilities
Weaknesses Low compressive strength, moisture issues Expensive and limited insulation capabilities Sound transmission, moisture issues
Applications Cheap, low-cost housing Chimneys, residential buildings Residential and commercial buildings

How are Earth Blocks Made?

compressed earth blocks production production of compressed earth blocks

A compressed block is made by preparing and mixing the soil, aggregate, and stabilizing agent. The mixture is then compacted, cured, and tested for strength before it's used in earthen construction projects. Follow this in-depth outline of how advanced earthen construction technologies transform soil and sand into one of the most eco-friendly building blocks today:

  1. Prepare Components
    Earth-compressed bricks use a combination of soil, sand, clay, and potentially a stabilizer like Portland cement. The ratio usually consists of 75% sandy soil, 15 to 20% clay, and 5 to 10% of silt. To achieve the right consistency of soil, it is sifted to remove leaves and debris. While this can be a tedious process, it's far cheaper than transporting soil to your site.
  2. Mix Components
    The mixture of soil, sand, and clay are stabilized with cement. Typically, Portland cement is used and makes up 4 to 10% of the final mix, depending on the type of soil. Finally, water is added to the mixture to reach the correct moisture content. If you're planning to make earthen blocks yourself, a good rule of thumb is that no moisture should be left on your palm after mixing the components together.
  3. Compact the Blocks
    To produce compressed earth blocks, you'll need to use an earth block press machine for the best results. This can either be a manual or gas-powered earth block machine based on your budget and project, but both options will still create a lower carbon footprint compared to concrete or brick-making block machines. To create your compressed earth blocks, machines use high pressure to compact the mixture into the distinctive shape you see in CEB construction.
  4. Cure the Blocks
    Once pressed, the CEBs will need to be cured to allow them to reach their full strength. Importantly, they need to remain moist until the seventh day to ensure the cement is properly hydrated. Then, the remaining curing process will take around 28 days in a humid environment away from direct heat.
  5. Quality Tests
    Once cured, the construction technique of the compressed earth block needs to be tested for strength and durability. If you use an earth brick machine, the quality of block produced should be enough to act as a load-bearing stone.

Compressed Earth Blocks vs. Bricks vs. Concrete | Technical Comparison

Compressed Earth Blocks Bricks Concrete Blocks
Estimated Cost to Produce (per block) $0.40 to $0.60 $0.50 to $0.90 $1.00 to $2.00
Materials Soil, sand, water, cement Clay, water, sand, firing additives (sawdust or coal dust) Cement, aggregates, water
Compressive Strength 2 to 5 MPa (4 to 9 MPa for stabilized blocks) 10 to 30 MPa 15 to 40 MPa
Modulus of Rupture 0.5 MPa 2.5 to 5 MPa 3.5 to 5 MPa
Dry Density 1,020 to 2,100 kg/m³ 1,680 to 2,220 kg/m³ 1,850 to 2,050 kg/m³
Thermal Conductivity 0.30 to 0.50 W/m.K 0.15 to 0.6 W/m.K 0.47 to 0.69 W/m.K
Environmental Impact Minimal Notable Significant
Applications Sustainable building projects (residential, commercial, infill); load-bearing and non-load-bearing walls. Façade cladding (decoration), structural walls, paving, fireplaces, and chimneys. Foundation and retaining walls, basements, commercial buildings.

Should You Use a Compressed Earth Block Machine?

Yes, you should use a compressed earth block machine to manufacture CEBs for your projects. The costs saved when using earth as a primary building material allow for budgets to include better equipment and services.

Lontto's LT5-10 Automatic Compressed Earth Block Machine can produce 5pcs of CEBs per cycle, resulting in a quick turnaround of impressive, stabilized CEBs. If you're interested in adding an energy efficient and low-cost CEB to your production line, take a look at our extensive offerings.

Compressed Earth Blocks vs. Bricks vs. Concrete FAQs

What sizes do Compressed Earth Blocks Come in?

Compressed earth blocks come in a wide range of sizes to suit the earthen building project you are undertaking. The smallest size CEB block is 4" x 12" and the largest is 10" x 14", and can include holes for interlocking.

Can you paint over Compressed Earth Blocks?

No, you cannot paint over compressed earth blocks. Paints and other insulating materials impact the breathability of the compressed soil blocks, decreasing their strength and durability over time. When building with CEBs you must also ensure the blocks are not exposed to any water or liquids for a prolonged period of time once cured.

What are Compressed Stabilized Earth Blocks?

Stabilized earth blocks are compressed earth blocks that have been mixed with cement to ensure their strength and durability. The cement absorbs the water within the dry inorganic soil block and reduces the chances that the blocks will succumb to water damage.

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chao zhang

Author: Chao Zhang

I am Chao Zhang, I have been working in the brick making industry for over 10 years. I have a deep understanding and research on various models of block making machines, especially automatic brick machines, concrete block machines, compressed earth block machines, clay brick machines, cement brick machines. I have a special understanding of this industry. I can help my clients choose the suitable brick machine and assist them in designing and building a brick production factory. If you want to know everything about brick making machines, please contact me. I am happy to help you.