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Installing a Downspout Under a Sidewalk (Step By Step)

Installing a Downspout Under a Sidewalk (Step By Step)

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We all know how harmful water can be to the structural integrity of a house. That’s why you must direct the liquid away from your home.

To do that, you can rely on tubing, like gutters to move the water to a nearby downspout. While this is an effective solution, the drainpipe can be an eyesore.

On top of that, it can get in the way and become a tripping hazard. So, if you’re trying to figure out how to solve these issues, you can install the downspout under your sidewalk.

In this article, we’ll talk you through everything you need to know about the process. We’ll also discuss what you can do to make installing the pipes easier.

How to Run a Downspout Under a Sidewalk

There are quite a few steps you have to follow to install a downspout under a sidewalk. To make your life easier, we’ll walk you through what you should do during every stage of the process.

Step 1: Inspect the Foundation

To install a downspout under a sidewalk, you’ll need to dig a few holes. This sounds like a simple task, but there are many considerations to make.

For starters, you have to take the foundation of the structures into account. Spend a little time examining the ground underneath your sidewalks.

The type of soil you find down there will determine the tools you need. For instance, with loamy or sandy soil, digging holes should be a walk in the park.

However, with clay or rocky soil, the process will be a bit more difficult. In that case, you may need to purchase specialized equipment to help you cut through the ground.

On the other hand, you can choose to hire a professional to do most of the heavy lifting.

Step 2: Check the Weather

Digging straight down into the soil can be an incredibly taxing activity. It’s even more strenuous if you decide to tackle the project during the winter.

As the ambient temperature drops, the water in the ground will begin to freeze. This will toughen the soil and make it next to impossible to dig through.

Besides that, during cold seasons, adhesives and binding agents take longer to dry.

For these reasons, it’s usually best to take on this project in the summer. You’ll have to deal with the scorching sun, but the process will take much less time.

Step 3: Gather Your Tools and Materials

Digging a hole in the dirt is a messy process. So, to avoid dragging mud through your house, it’s best to gather all the tools you need next to the project site.

Not only will that help you keep the disorder at a minimum, but it’ll make the process go by faster. Here’s a look at the equipment you’ll need to install a downspout under your sidewalk:

  • Chalk
  • Shovel
  • Trenching machine
  • PVC pipes
  • Gravel
  • Plastic tarp
  • Towel
  • Gloves
  • Safety goggles

You should be able to purchase all these tools at your local hardware store, but you don’t have to. Some equipment, like the trenching machine, can cost a pretty penny.

Because of that, instead of buying the tool, you can opt to rent it for a short period.

Step 4: Map Out the Project

Before you get your hands dirty, it’s a good idea to have a plan in mind. Start by putting on your safety goggles and gloves.

After that, lay down the plastic tarp and use your tools to weigh it down. This will give you a nice clean area to help you move around.

In addition, the tarp will make cleaning up after the process a breeze.

Once that’s done, it’s time to decide where you want the downspout to go. Then, lay down your PVC pipes on the ground to create a network that connects to your drainage system.

While you do that, ensure that the pathway is as straight as possible. Remember, water will flow through the pipes and drain out the other side.

That means it’s best to avoid installing U-shapes or excessively winding pipes.

Next, use your chalk to mark where each tube goes. This will act as your blueprint while you dig.

Step 5: Decide How Deep the Pathway Should Be

The main idea behind installing a downspout under the sidewalk is to hide pipes out of view.

For that reason, you have to ensure you dig holes that are large enough to completely cover the tubes.

Most of the time, the diameter of the trenches should be between two and three inches. This should be wide enough to accommodate the PVC pipes.

Other than that, you have to consider the depth of the holes.

Typically, a trench that’s about two feet deep should do the trick. Although, this can change depending on where you live.

If you’re staying in a particularly cold area, then the holes may need to be around four feet deep. This will allow the soil around the pipes to act as a natural insulator.

That should stop the water running down the tubes from freezing up during the winter.

Step 6: Dig a Trench

Now, with your plan in place, you’re ready to begin digging.

If you’re dealing with sandy soil, all you’ll need for this part is a shovel. The tool should be strong enough to carve through the ground.

However, with rocky soil, you’ll need a heavy-duty helper. A trenching machine will be able to dig through any type of soil with minimal resistance.

On top of that, the gadget has the added benefit of being speedy. Plus, you won’t have to exert that much effort to operate the machine.

While you’re digging out the trenches, keep an eye on the slope of the sidewalk. Make sure you maintain the angle of the surface.

This will make it possible for you to rely on gravity to drain any excess water.

Finally, spread out a four-inch layer of gravel at the bottom of the trench. The tiny rocks will provide support to the pipes and stop them from moving around.

Step 7: Run the Pipes Underneath the Sidewalk

At this stage, you should have a clear pathway for the PVC pipes. All that’s left is running the tubes through your trenches.

This part may take a little while, so be sure to be patient. Focus on securing the joints between the pipes to reduce the chances of water leakage.

Once all the tubes are in place, use your shovel to fill in the space with dirt. Lastly, pat the ground down and compact the soil to secure the pipes in place.

Can You Put a Downspout Over a Sidewalk?

It’s possible to run your downspout over a sidewalk, but it’s not ideal. That’s mainly because of potential water damage.

When a drainpipe is above ground level, the chances of wear and tear are quite high. Due to the weather and other factors, the tubes will degrade over time.

This will cause them to leak onto your sidewalk. After a while, the concrete will begin to crack and may even crumble altogether.

Can You Drain Water Over a Sidewalk?

You can drain water over a sidewalk, but there are a few issues that go along with that.

Draining water relies heavily on gravity. We use this natural force to pull the water from one location to another.

That’s why the slope of your drainage system is crucial.

With the pipes above ground level, maintaining the angle will be a bit tough. Because of that, the tubes can accumulate water, which may lead to a leakage.

Downspout Under Patio

If your downspout runs directly above your patio, you’ll need to redirect the tubes. While installing the pipes under the deck is possible, it can lead to major problems.

If water collects under a patio, it’ll cause the soil beneath the structure to expand. This will affect the integrity of the deck and lead to cracks forming on the surface.

For that reason, it’s best to install the downspout a good distance away from any structures in your yard.

Final Thoughts

If you’re trying to run a downspout under sidewalks, there are a few steps you can follow. Start by inspecting the foundation and checking the weather conditions.

After that, gather the necessary tools and map out your pipe network. Next, it’s time to decide on the depth of the holes and then dig them out.

Finally, run your pipes through the pathways and fill up the space with dirt.


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