Compare Plastic and Concrete Septic Tanks When You Need a New Tank

If you're putting in a new septic system for the first time or if you need to replace a bad tank, you get to decide on the type of septic tank you want to install. Two common choices are plastic and concrete. First, check with your local codes office to see if a certain type of tank is required since some places only allow concrete. If you have a choice, then you'll want to compare the pros and cons of each. Here's how they compare.

Plastic Is Easier to Install

A benefit of a plastic septic tank is that it is lightweight, so it is much easier to install. This could keep costs lower and make it possible to install a tank in an area where large trucks and heavy equipment can't navigate. You could buy a plastic tank yourself and bring it home in your truck. The installation crew can move it to the hole and install it without the need for heavy equipment. In comparison, a concrete tank has to be delivered on a flatbed truck and moved from the truck to the hole with a crane.

Plastic tanks are designed to be durable. Instead of smooth sides, the plastic is made with ridges so the tank is tough and so dirt can fill the grooves between the ridges and help hold the tank in the ground. However, a possible downside is that the tank could float out of the ground when the soil is saturated with water.

A plastic tank might also be damaged when driven over, or when soil shifts. But as a plus, plastic has a slight elasticity, so it can flex a little rather than crack. A plastic tank could be the right choice if you have a tight budget or if you're installing the tank in a hilly or remote area where it isn't possible to transport a precast concrete tank.

Concrete Can Last For Decades

A concrete tank is considered more durable than plastic, and it can last for many decades as long as it's maintained well. Concrete is very heavy, so it usually won't shift once it's in the ground. The tanks are usually delivered already made and ready to place in the ground. However, it might be possible to find a contractor who can build a tank on site.

Like anything else made of concrete, concrete can crack, but cracks can usually be filled to prevent leaking and to prolong the life of the tank. Concrete might also corrode due to exposure to toxic fumes. For instance, the baffle might corrode away. But these problems can often be repaired and even avoided through proper maintenance.

If you think you'll live in your home for decades to come and you want the most durable septic tank possible, then concrete might be your best choice.