The Pros and Cons of Using Recycled Plastic Bricks to Build
You may have heard that plastic waste has become a serious global environmental problem – it pollutes land and our water bodies.
As we strive to tackle this problem, some companies are taking creative approaches like building with recycled plastic bricks.
However, before going this route, you’ll want to know the pros and cons of using recycled plastic bricks to build.
Recycled plastic bricks are sustainable building materials and an eco-friendly way to deal with plastic waste. However, as a homeowner or builder, you want to be sure that any material you build with can stand the test of time.
In the rest of this article, I’ll discuss the pros and cons of using recycled plastic bricks to build. I’ll cover everything from the strength of the material to its performance in extreme weather.
This will answer all your questions about whether recycled plastic bricks are an ideal building material for your project.
Recycled Plastic Bricks as a Building Material
More than 380 million tonnes of plastic are produced annually. Unfortunately, many of these plastics are released into the environment as waste at the end of their service lives.
Less than 10 percent of the billions of tons of plastics generated since the 1950s has been recycled. 79 percent of these plastics have ended up in landfills and oceans, where they will remain forever in one form or another since plastic doesn’t decompose.
The construction industry is the largest sector in many economies and the highest consumer of raw materials. It is, therefore, important that the sector finds a more sustainable way to manage plastic waste.
It’s worth mentioning that recycled plastic bricks can make an excellent building material if manufactured using appropriate techniques and the right type of plastic.
There are different types of plastic materials with different compressive and tensile strengths. Some are weaker and unsuitable for making building bricks.
Low-density polyethylene (LDPE) and polyethylene terephthalate (PETE) are excellent plastic materials for making bricks due to their durability, strength, and low thermal conductivity.
The table below shows plastic materials used in the construction industry, their properties, and their most suitable applications.
| Plastic Material | Physical Properties | Best Application |
| HDPE | Rigid | Plastic lumber, tables, chairs |
| LDPE | Flexible | Bricks and blocks |
| PP | Hard and flexible | Bricks and aggregates in asphalt mixture |
| PS | Hard and brittle | Insulation material |
| PET | Hard and flexible | Fibers in cementitious composites |
| PC | Hard and rigid | Aggregates in cementitious composites |
Table 1: Plastic materials best for bricks and other applications. Source: Science Direct
The Pros of Using Recycled Plastic Bricks to Build
Excellent Insulation
Insulation is an essential factor when choosing a building material. According to Energy Saver, insulation provides resistance to heat flow and, thus, helps save on heating and cooling costs. It also makes the house more comfortable.
Plastic is an excellent thermal insulator because it’s a poor conductor of heat. Unlike metals, plastics don’t have free electrons to conduct heat.
A thermal insulation test revealed that recycled plastic bricks have a U-value of 0.25 Watts per meter Kelvin (W/m²K). This is ten times better than conventional clay bricks that have an average U-value of 2.94 W/m²K.
The above features make recycled plastic bricks ideal for building in very hot or cold climates and regions with large temperature variations.
Sustainable Construction
The construction industry has a huge impact on the environment. The industry consumes up to 40 percent of all energy used and generates up to 30 percent of the annual global greenhouse gas emissions.
The above statistics could be improved by using more sustainable construction materials.
Recycled plastic bricks contribute to sustainable construction in the following ways:
- They support enhanced recycling and reuse of existing plastics, reducing the need to produce virgin plastic, which takes more energy and releases more greenhouse gases.
- Recycled plastic substitutes for high-emission materials such as steel and concrete bricks.
- Reducing plastic waste pollution in landfills and oceans.
Strong and Highly Durable
Plastic bricks can be an excellent option if you want a stronger and more durable building material.
Plastics are fibrous in nature. The fibers are intertwined in a matrix, forming an incredibly strong material that can withstand extreme weather conditions and high pressures.
Moreover, the production process uses hydraulic machines for compression to remove air pockets and make these bricks very strong.
As Nzambi Matee, the founder of Gjenge Makers testifies, their recycled plastic bricks are two to seven times stronger than their concrete counterparts.
For your comparison, the table below shows that mixtures of plastic with a smaller amount of sand produces bricks with higher compressive strengths than when high volumes of sand are used.
| Plastic: Sand Ratio | Maximum Load (KN) | Compressive Strength (N/mm2) | Water Absorption |
| 1:2 | 232 | 9.17 Mpa | 0.346% |
| 1:3 | 162 | 6.4 Mpa | 1.57% |
| 1:4 | 88 | 3.5 Mpa | 1.467% |
Table 2: The impact of plastic to sand ratio on compressive strength of plastic bricks. Source: AZO Cleantech
Aesthetically Pleasing
Plastic bricks can make an excellent addition to your home’s interior and exterior design. The materials come in different attractive colors and shapes, allowing you to add a personal touch of color to your walls, floors, or outdoor pathways.
The Cons of Using Recycled Plastic Bricks to Build
Highly Sensitive to Fire and High Temperatures
Plastics are made from thermoplastic polymers that undergo thermal degradation when exposed to high temperatures.
When exposed to fire or temperatures exceeding 400°C (752°F), recycled plastic bricks are likely to melt and release toxic fumes. Thus, they are more prone to fire accidents than other materials such as concrete or stone.
Expensive
Recycling plastic waste and turning it into bricks is a labor-intensive process that requires various machines and technologies. The long process involved increases the production cost of these bricks.
The high production cost translates to a more expensive building material than concrete or clay bricks.
However, although plastic bricks have a higher initial cost, their energy-saving characteristics and durability help you reduce overall costs in the long term.
Difficulty to Repair
Repairing plastic bricks is not easy. If damage occurs, it might be difficult to remove and replace the affected part without damaging the entire structure.
Moreover, once some plastic brick designs are installed, it’s hard to make adjustments or change a smaller portion without affecting the rest of the structure.
Environmental Pollution
Recycling plastic to manufacture bricks uses high temperatures, releasing toxic gases like dioxin. These gases have a severe environmental impact when released into the atmosphere.
Moreover, like any other polymer, plastics are prone to photodegradation when exposed to sunlight for a long time.
Wavelengths such as infrared radiation, ultraviolet light, and visible light degrade the photodegradable molecules, releasing microplastics into the surrounding environment.
Microplastics are harmful to the environment and can affect aquatic life negatively. Exposure to these microplastics also causes oxidative stress, inflammation, and DNA damage in humans.
Therefore, it’s important to avoid open exposure of recycled plastic bricks to direct sunlight as much as possible. You should also aim use UV-stabilized recycled plastic bricks if possible.
Final Thoughts
The choice of building materials comes down to the characteristics required for any given project, including physical and aesthetic properties.
Recycled plastic bricks offer excellent strength and insulation characteristics but can be expensive and release toxins in the event of a fire.
They are a sustainable alternative to materials that have more embodied energy and could be the right choice for you if you have the budget and are looking to minimize the impact of your project on the environment.
Now that you know the pros and cons of using recycled plastic bricks to build, you can determine if they are the best option for your own building project.
Before leaving, check out this article for the top ten sustainable building methods.
