Can You Build A Deck Over A Septic Tank? (Explained)

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You can always build a deck over a septic tank. However, understand that this is not ideal for a couple of reasons. What if you need to perform maintenance on the septic system, such as the field lines and the tank? It’s certainly possible to build over a deck; but, it’s not a good idea.

Backyard deck with wicker furniture and pergola.

What can you put on top of a septic tank?

You can always build several things on your septic tank. Before going ahead to list some of what you can build on the septic system, let me quickly talk about what a septic tank is and how it works.

Here’s what you need to know about the septic tank

A septic tank is an underground container, made of fiberglass, plastic, or concrete, that receives wastewater and other organic materials coming from your home. The tank is primarily designed to enable the treatment of wastewater through biological decomposition and drainage.

Here’s how the septic tank works:

First, you need to know that the underground septic tank is only connected to a single drainage pipe from your household. The pipe is also called the inlet pipe.

As wastewater and other organic materials are flushed down the inlet or drainage pipe, they flow directly into the septic tank.

Inside the septic tank, a lot of things happen – for instance, the wastewater and organic waste are separated into three things.

First, solid substances are allowed to settle out at the bottom of the tank, forming sludge.

Second, greasy and oily substances are allowed to float on the surface, forming scum. As for the wastewater, it represents the effluent and it’s allowed to move directly from the septic tank to the drainfield, which other processes, such as filtration through the soil, are carried out.

Furthermore, inside the septic tank, there are large colonies of bacteria and enzymes. Their primary function is to work on organic substances. The bacteria help to break down the organic materials.

According to the United States Environmental Protection Agency (EPA), it’s recommended to inspect and perform maintenance service, including pumping out the sludge in your septic tank at least every three to five years.

With that, it means septic systems require regular maintenance for a better lifespan. Let me pause here and talk about what you can build on your septic tank.

Things you can build over your septic tank

One thing that people build over their septic tanks is a swimming pool. Well, it’s okay to build a pool over a septic tank, especially if it’s an above-ground swimming pool.

I’m saying this because above-ground pools are known to be temporary structures. They don’t alter the landscape of your yard since they are usually built on the surface of the yard rather than inside the landscape.

Furthermore, people can also build a deck over a septic tank. The only problem, however, with this type of installation is that most decks are permanent. However, it’s not a wise thing to install permanent structures over your septic tank because of septic system maintenance.

Instead of building a permanent deck structure, you can always consider opting for a temporary structure – that’s if you’re really interested in installing the structure over your septic tank.

Apart from swimming pools and decks, other things you can consider putting over your septic tanks are perennials and grasses, including ornamental grasses. The reason for that is simple; perennials and grasses have shallow root systems.

As such, you can always rest assured that they won’t interfere with the underground septic tank, causing problems.

Here’s why you need to watch what you build over your septic tank

There are a couple of reasons you need to watch what you build over your septic tank.

For instance, if what you’re looking to build has something to do with the alteration of the landscape of your yard, then you need to be careful.

This is because you might end up puncturing the leach field lines of your septic system during the process of installing the structure.

Unfortunately, puncturing of the leach field lines is a couple of serious problems. For instance, the ground will become muddy and wet.

Apart from that, you’ll also have the air filled with putrid smells. It costs a lot of money to fix these issues.

Another issue with installing a permanent structure over your septic tank is the maintenance of the septic system. As you already know, it’s important to perform maintenance service on the septic system every three to five years.

This includes pumping out the sludge inside the tank to prevent it from overfilling. But how exactly will you perform the maintenance work if you have a permanent structure over the septic tank?

The bottom line is that you can always build a lot of things over your septic tank. However, when doing that, ensure to stay away from installing permanent structures.

Doing that is not wise and will most likely introduce a couple of issues sooner or later.

Can you build a deck over a septic tank?

The answer to this question depends, to a very large extent, on the type of deck you’re looking to build. If you’re considering installing a permanent deck over the septic tank, you need to understand that this is not a wise idea.

While it’s possible to build a deck over a septic tank, it’s just not ideal because of a couple of reasons. It’s recommended to perform maintenance service on your septic tank every three or five years.

If you end up building a deck, most especially a permanent structure, over the septic, you’ll have an issue when it comes to maintaining the septic system – something that you must do.

So, the bottom line is that it’s not ideal to install a deck over a septic tank. If you must do it, you can consider erecting a temporary deck structure.

How close to the septic tank can I build a deck?

As earlier mentioned, it’s not a good idea to build over or near your home’s septic tank. However, if you must do that, you need to keep at least a 5ft setback from the septic tank.

Concrete pouring during commercial concreting floors of building

Can you pour concrete over a septic tank?

In construction, paving can be defined as the superficial surface covering the ground with different materials, such as asphalt, concrete, and stones. Paving over a septic tank is not entirely a bad idea.

However, you need to understand that making the move can always present you with a couple of issues.

You should never pour concrete over a septic tank. For you to perform paving with concrete materials, there are certain minerals and structures that you need to use. However, this can become a burden for your septic tank – most septic tanks aren’t strong enough to withstand pressure.

Also, if there’s an issue with our septic tank, fixing it will be a lot more costly and time consuming.

So, the bottom line is that it’s not ideal to pour concrete over your septic tank. If you must do it, let a professional run a check for you and be sure it’s okay to carry on with the project.