4 Types of Septic Tank Materials

The septic tank is an underground system that collects and treats sewage through various methods. Most septic tanks use bacterial decomposition to treat the sewage. Contractors use different materials to construct septic tanks. Here are the most common materials used for septic tank construction.

1. Concrete Septic Tank

Concrete septic tanks are massive, and most are pre-casted for easy installation. The precasting usually produces two pieces with a seam at the middle or lid. Precast septic tanks have a specific gravity that can withstand strong forces in the ground. The tanks are also resistant to environmental changes and can have an extended lifespan.

Concrete septic tanks are stronger than many other materials, particularly if they have blended compounds, like asphalt-based sealants.

Today, most concrete septic tanks are available as an all-in-one system or single-structure system. Regardless of the design, various environmental factors, such as changing soil conditions and tree roots, can cause leakages. The outlet and inlet penetrations can also leak if the tank shifts due to improper installation or weak bedding.

2. Fiberglass Reinforced Septic Tank 

Fiberglass-reinforced plastic septic tanks are made from fiber-reinforced plastics. They are available in one- or two-piece designs that are lighter in weight and easier to install. Manufacturers use an injection molding process to create the fiberglass-reinforced plastic. If the manufacturer uses high-quality raw materials, the fiberglass septic tanks will be strong and won't corrode like steel or concrete septic tanks.

If you buy two-piece fiber-reinforced plastic tanks, the manufacturer will likely send them unassembled. The installer will verify that the tank has the appropriate adhesives to hold it firmly in place. If the process doesn't happen properly, the tank can shift once the surrounding soil saturates, causing leaking.

3. Steel Septic Tank

If you're looking for the best material that can withstand buoyant forces, consider steel septic tanks. If the water level near the tank rises, a steel septic tank won't float. However, most homeowners are unlikely to choose steel tanks because the disadvantages may outweigh the advantages. The main disadvantage is that steel septic tanks are not long-lasting, even though steel is one of the most durable elements in nature.

The short lifespan of steel tanks is because the material begins to rust easily. A rusting steel septic tank weakens and won't support the materials above. This can lead to dangerous situations, and an animal or person can fall into the tank. Removing the corroded steel septic tank is also difficult, but you can remove only the top cover of the tank to save money. Steel septic tanks are also more costly than most other tanks.

4. Plastic Septic Tanks

Plastic septic tanks consist of chemically inactive polyethylene material. The tanks are good alternatives to steel and concrete tanks since they are affordable, lightweight, and long-lasting. Plastic tanks are also non-porous and are not prone to rust like steel tanks or cracking like concrete tanks. This prevents wastewater exchange between the inside and outside of the septic tank.

Installers must be careful during installation to protect the structural soundness of the plastic septic tank. This is because the septic tank is lightweight and can crack during installation. The tank can also float if the water table is quite high. In particular, the installer must properly seal pipe penetrations and riser joints to prevent leaking.

Plastic septic tanks can also collapse under heavy weight or high pressure. For example, water and connecting pipes can destroy your plastic tanks. You should always review the manufacturer's installation instructions to know if the plastic tank can withstand pressure in your home.

Once you decide on your ideal synthetic material, JT Sanitation will help you to install a septic tank. Our team of experts installs, repairs, and maintains septic tank systems. Contact us for more information.