When installing a septic system, one of the most important decisions you’ll need to make is choosing the right septic tank material. The two most common types of septic tanks are concrete and plastic (often made of polyethylene). Each type has its own set of advantages and disadvantages, and the right choice for your property depends on various factors such as cost, durability, and local regulations.
Concrete Septic Tanks
Concrete septic tanks are the traditional choice thanks to their durability and long lifespan. They don’t corrode like metal tanks and they don’t wear out as fast as plastic ones.
Advantages of Concrete Septic Tanks
Concrete septic tanks are durable, long-lived, strong, stable, and corrosion resistant, which makes them a good default tank for you septic system.
Durability and Longevity
Concrete is an incredibly durable material that can last for decades if properly maintained. Concrete septic tanks are known to withstand the test of time and can endure the weight of the soil above them without collapsing. When installed correctly, a concrete septic tank can last anywhere from 40 to 50 years, and in some cases even longer.
Strength and Stability
Concrete tanks are designed to handle heavy loads, making them ideal for properties with heavy traffic or areas that are prone to flooding. The solid structure of a concrete tank provides added stability, which is particularly important in areas with high water tables or unstable soil conditions.
Resistant to Corrosion
Unlike metal tanks, which are susceptible to corrosion over time, concrete septic tanks are resistant to rust and deterioration. This makes concrete an excellent choice for long-term reliability in various environmental conditions.
Disadvantages of Concrete Septic Tanks
The disadvantages of concrete septic tanks are the weight, installation difficulty, higher upfront investment, and risk of cracking.
Weight and Installation Difficulty
One of the biggest drawbacks of concrete septic tanks is their weight. Concrete tanks are extremely heavy, which makes them difficult and costly to transport and install. Installation typically requires heavy machinery and more labor, which can increase the overall cost of the installation.
Risk of Cracking
While concrete is durable, it is not impervious to damage. Over time, concrete can crack due to settling, shifting soil, or ground movement. Cracks in the tank can lead to leaks, which may result in contamination of the surrounding soil and water. Regular maintenance and inspections are essential to catch and address cracks before they cause significant issues.
Plastic Septic Tanks
The more modern alternative to concrete septic tanks, this option is popular due to the easy install process, which means lower prices.
Advantages of Plastic Septic Tanks
Plastic septic tanks are light, easy to install, budget friendly, corrosion resistant, and less prone to cracking than concrete tanks.
Lightweight and Easy to Install
Plastic septic tanks are much lighter than concrete tanks, making them easier to transport and install. The lightweight nature of plastic allows for quicker installation, which can lower labor costs and installation time. This is especially beneficial for properties with limited access or challenging terrain.
Corrosion-Resistant
Unlike concrete, plastic septic tanks are impervious to corrosion and rust. They are not affected by the elements, such as moisture, which makes them an ideal choice for areas with high groundwater levels or areas that experience frequent flooding. This corrosion resistance ensures a longer lifespan without the need for regular inspections for rust or deterioration.
Less Prone to Cracking
Plastic tanks are less likely to crack than concrete tanks, especially in areas with shifting soil or seismic activity. Their flexibility allows them to better withstand pressure from the surrounding environment. This makes plastic tanks a safer choice for locations with unstable ground conditions.
Disadvantages of Plastic Septic Tanks
The reasons to not get a plastic septic tank comes down to durability. These tanks are more susceptible to damage from weight or sharp objects, direct sunlight, and have a higher potential for leaks than concrete tanks.
Less Durable
While plastic tanks are less likely to crack, they are generally not as durable as concrete tanks. They are more susceptible to damage from impact or sharp objects in the ground. Plastic septic tanks also may not hold up as well in areas with heavy traffic or where vehicles frequently pass over the tank.
UV Sensitivity
Plastic septic tanks can be vulnerable to UV radiation, which can cause the material to degrade if exposed to sunlight over time. However, most plastic septic tanks are made with UV inhibitors to minimize this issue. Still, it’s important to keep the tank covered and protected from direct sunlight to prolong its lifespan.
Potential for Leaks
While plastic tanks are resistant to cracking, they may still develop leaks over time, particularly around the seams or fittings. Ensuring the proper installation and maintenance of the tank is essential to prevent leaks that can lead to contamination.
Which One Is Right for Your Property?
The questions comes down to timeline: If you want to make a long term investment you should probably get a concrete tank, which will cost more upfront, but last longer and be more durable than plastic. Plastic tanks are good for those who can’t afford a concrete tank, are unable to get a heavy concrete tank onto their property, or anticipate needing to replace their system sometime not too far in the future.