Before taking on any new construction project or renovating your property, it is essential to make sure that the project you are going to take on is within set limits.

The task at hand should be physically possible, should match up with your layout, and should not violate any construction limits.

Working near buried septic lines specifically have tons of limitations that must be kept in mind before beginning any project. One common question that most people ask is whether you can build a shed over a sewer line. 

In this guide, we are going to discuss risk of building near buried drain piping and septic lines, and more.

What Are The Construction Restrictions Around Sewer Lines?

Some homes may be too small to accommodate all the basic storage and rooms required. In such a scenario, people often think about building a shed to get more storage space. It also helps expand the property as a whole.

However, this idea is not very straightforward as you might think. Building a shed is not always an easy project to take on. Such a  project can get more complicated if there are one or more sewer or field pipes underground in the area you wish to build the shed.

Buried sewer pipes

Can You Build A Shed Over A Sewer Line?

No. Construction of a shed over to a sewer line is prohibited. You will not even be able to build a shed near or close to a sewer line.

Yet, there are a few scenarios in which it is acceptable to build your structure. You must submit a letter for approval to your local authorities or council and obtain a building permit.

They will allow you to continue construction if they feel that your shed will not obstruct pipelines or hurt any other infrastructure.

You will also be provided with a safe distance. This is usually 3 meters away from sewerage pipes, so any construction disturbance will not damage the pipes or drains.

Any heavy weight or pressure on the soil near the area can cause pipes to bend or face obstructions which is a big no. Any pipe damage could also be irreversible, and repair may be very hard. Therefore, following the rules and playing it safe during construction is your best bet.

Knowing how deep down the sewer lines are laid under the lawn is also a good idea to assess how safe pressure on the surface is. Doing so will prevent any weight on the pipes completely. 

You can easily find the depth in the official documents provided to you, so make sure you read these thoroughly before starting your project.

Is It Allowed To Place Concrete Slabs Over Sewer Lines?

If you have set your heart on building a shed in your yard to increase storage, you may wish to use concrete slabs for the flooring.

Concrete slabs are necessary to prevent sunken doors that will not open or close due to the building leveling down.

Most constructions sink by an inch or two once complete, but whether this will affect pipes adversely depends on the care taken.

Concrete slabs can easily sink into the soil and prevent pipes from contracting and expanding due to water flow or temperature changes. Even though the sinking effect may be barely noticeable at a glance, it can obstruct the sewer pipes completely. 

The added pressure can cause pipes to crack or burst, and repair is something you do not want to face. Damaged pipes can also cause your yard to be flooded with dirty sewer water. It can flood your entire property, damage other construction, and will also leave a terrible odor.

Using a concrete slab for your shed

Getting Approval

Approval means you can construct what you desire without damaging or obstructing pipes. Some pipes may be at a greater depth underground, so you might be able to add weight on top without doing any damage.

However, it is up to your local authorities or council to decide whether your construction is eligible.

You may have water company representatives come over to inspect the site once you submit your proposal. You can also hire a professional to inspect for you.

Approval depends on many factors, such as the underground depth of the pipes, their material, and the weight of the proposed construction design. You can start your project once your local council confirms there are no risks involved and you get an approval letter.

Since construction over or near sewer pipes is risky, it is better to avoid it altogether. If possible, move a few meters away from the site altogether. 

What Does Shed Construction Approval Cover?

If you decide to go along with approval, here is what you might want to know:

Where Does It Apply?

Care must be taken on projects that are being built near any sort of infrastructure. Not only is it a good idea to get approval for construction near sewer lines, but you should also take care of standard regulations. Ensure you are registered with a relevant service provider to obtain accurate information. 

Where Is It Not Applicable?

You do not need approval or consent if your project is far from infrastructure or pipelines. 

However, the safe distance may vary based on local rules. It is necessary to be at least 3 meters away from houses, buildings, or other private garages for Class 1 and Class 10 projects.

Your construction should be at least 5 meters away for Class 2 to Class 9 projects.

Classes and distance may vary based on the region you reside in, so make sure to check local rules.

Sewer pipes are elaborate near apartments and complexes, so it is a smart move to stay a greater distance away from them when setting up your project. It can cost you a fortune if you end up damaging overlapping pipelines.

Stay 10 meters away from any bolts or ground anchors. You might not need approval if you are not altering the floor of the building you wish to construct.

Building a shed near a sewer line

Can You Pour Concrete Over Sewer Pipes?

You can pour concrete over sewerage pipes. However, the use of a gravel bed that wraps around the pipe allows the pipe room to expand and a contract is needed.

Plus, the gravel does not leave any open gaps, which makes the cement pour safer.

Gravel also helps evenly distribute any weight or pressure on the pipes and prevents them from cracking or bursting. Therefore, it is a good idea to pack the sewer pipe entirely without leaving any air holes or gaps.

The depth of the pipe must also be taken into consideration. Once the concrete is poured in and something is constructed on top, it can add a lot of pressure on the soil. This may cause the soil to shift, so cover the pipe with the proper gravel width to prevent this.

What Happens If You Build Over A Sewer?

If you are building over a sewer, ensure you have approval and do not build the new foundation too close to the pipelines. Pipes should be redirected if needed, and access for maintenance of the pipes must be present at all times.


Constructing a new storage area or a shed should be a breeze if you plan ahead. Make sure you get the necessary consent, follow all rules, and try your best to stay as far away from sewer lines as possible. 

Remember that you could get legal notice for damaging pipes or other infrastructure. To prevent paying maintenance and repair costs, it is necessary to follow all legal rules before construction.