Home » Gardening Tools & Products » How To Make & Install French Drain – Complete Guide

How To Make & Install French Drain – Complete Guide

Too much water in the ground is not good for your plants and trees, and this is when French drains are useful. We are going to discuss a thing or two about how to make and install French drain and relatable aspects today. You can solve many other water problems with French drains, and you are going to learn about them here also. From the benefits and drawbacks to how to install a French drain and more, I include them all for you. Let’s find what French drains are and how they work as well as several other things below.

What Is A French Drain?

The system of a French drain simply utilizes a trench, an underground perforated pipe, and gravel on top. It looks nice and works great, and directs surface water toward the lowest point on the perimeter of your home. It collects groundwater and surface water then redirects it into a more appropriate outlet. Depending on your location and situation, a French drain can divert water to various destinations that are available. Some of the most common ones are a drainage ditch, dry well, low-lying area on the property, or the street.

A French drain is very effective because it collects water over the entire length of the drain. It can prevent water from collecting and pooling above the ground that can damage your basement, driveway, foundation, lawn, etc. The gravity will help with the job to guide water in its pipe towards the drainage destination of your choice. As for the gravel, it prevents debris from gaining entry into the system while creating a nice appearance.

How Does A French Drain Work?

Just like how gutters collect rainwater and transfer it to a different part of the house, a French drain has a similar task. It drains water from the top of the ground so that your lawn or yard won’t flood. On uneven grounds, large water puddles are very common in low spots and French drains are the solution to those. French drains provide an easy and lower channel so that water can flow through.

The concept of a French drain is to create a slightly sloped trench filled with gravel. Then the pipe in the system will divert water away from the unwanted area around or in your house. The water travels freely through the pipe every time it reaches the level you install the drain. This is to ensure that unwanted water issues will not occur again.

Benefits Of French Drains

As you know how about they work, French drains are very beneficial in so many ways. They keep the ground dry, prevent water from accumulating, and many more. To give you a detailed insight, below are some of the main advantages of French drains you should know about.

Affordable Price

French drain installation is relatively inexpensive in some spots, and you can actually do it yourself too. If you know how to make a French drain at home, you won’t even need special tools to achieve it. Just make sure to do your research, especially the locations, and you are good to go. In case things are a little too tricky, you can always hire a professional to handle the jobs for you.

Damp Spots

This is one of the most common things people often see on their lawn or yard. There is always at least this one spot that is more damp and wet than the other areas around it. If the spot is small, then it is not a big matter of concern. However, it is not a pleasant sight to see if it is too large and noticeable. With a French drain, this won’t be an issue that you will have anymore. It helps you keep your lawn or yard equally dry, and it will look so much better and nicer.

Prevent Water Damage

Moist lawns or soggy grounds are both uncomfortable and unpleasant to look at, but there’s more. It can also damage the surfaces when this problem remains for too long which is why you need a French drain. Once you install a French drain underground, it will effectively channel the water away from those areas. That way, you won’t have to worry that your driveway, lawn, or playground is damaged by the water anymore.

Wet Basement

Another common issue that some people experience is a wet basement after heavy rain or storm. There are basements that admit water through the foundation, leading to leaking. Sometimes outdoor drainage can fix that issue, but sometimes it does not. This is why you should install a French drain to get rid of this problem permanently. French drains can also solve this problem by rerouting the water and depositing it in another area.

Drawbacks Of French Drains

Along with the advantages, there are also some disadvantages of French drains to consider. This is also an important aspect that you should have in mind before you decide to install a French drain. The thing is that the drawbacks do not apply to every case, so take a look below.

Damages

Things are okay if the French drain that you want to install is in free or open space. However, there could be a lot of damage if it has to be under existing structures like decks and walkways. You will have to dig them up and remove them to install the drain and put them back. This is both costly and time-consuming because it takes quite some time to install the deck or walkway back in place.

Possible Danger

French drain installation can be dangerous if there are communication, power, or water lines buried underground. This is why you should always thoroughly check before you start digging the trench. And this is also the reason why the professionals can handle this better and safer for you. In some states like Massachusetts and Maine, it is compulsory to notify the municipal authorities prior to digging for safety purposes.

Water Overflow

Without a proper installation, French drains may sometimes clog, which will lead to water overflow issues. In case the drain is a little far, or if you are busy, you are not able to check it on time. That is when it can lead to problems such as damages due to flooding in the basement and yard.

French Drain Types

A French drain comes in a few different types that work with various problems that you come across. Knowing the right type of French drain is important because you are able to fix the issue right away. This also helps save the cost since you won’t have to re-install it in case you chose the wrong type. Below are some of the French drain types and what they are suitable for.

Deep French Drain

This is the type of French drain that you should go for when the water is getting into your basement. It also goes by the name Footing Drain, and it runs around the house at a footing level. What it does is intercept the water before it has a chance to get into your basement.

The best time to install a deep French drain is during house construction because it is extremely costly to add after. And if you don’t have a choice, then you will need to spend a lot to install it. This is because there will be digging to access the foundation footing during the installation process. It is also possible that you will have to watch your decks or walkways being ripped out to install the drain.

Interior French Drain

Now, this is the solution to a deep French drain because it works almost exactly the same. It also intercepts water, but it does so when the water enters the basement. This drain makes sure to keep your basement dry, and it is cheaper and easier to install. The only problem is that you will have to remove interior walls to install this system.

Shallow French Drain

Also known as a Curtain Drain, this type of drain is ideal for problems with surface water. The size of this drain is not very deep, usually around 2 feet deep and 1.5 across. Its structure extends horizontally across your property, and it goes directly uphill of the area that you want to dry out. Its main task is to stop water in its track and reroute it from the soggy spot. When you install it, use a solid pipe if the drain goes through areas with shrubs or trees. This is to prevent their roots from growing into the pipe and damaging it.

How To Install A French Drain

You can actually install a French drain by yourself at home using some DIY methods. It does help to save some cost, and you probably have enough tools if you are a handy person. In case you want things to more convenient, you can always hire a landscaper to do the jobs. Below is a quick guide on how to make a French drain in yard that you can follow.

Materials

  • A shovel
  • A fabric filter
  • Gravel or landscaping stones
  • Perforated pipes or PVC pipes

French Drain Installation

Step 1: Location

Before anything, you should figure out where the excess water is pooling and where you want to reroute it. The ideal locations for runoff water should be where the water can be safely drained in. Those should be retention ponds and other bodies of water or the road curbside if it is nearby. Make sure that the pipe system and the trench drain water from a higher elevation to a lower elevation.

Step 2: Dig A Trench

After you have determined the location, the next thing to do is start digging a trench. Dig it from the place in your yard all the way to the outlet that you decide the water should go to. There are a few things to have in mind before and during trench digging which include:

  • Check for pipes and utility lines underground before digging.
  • Make sure that the slope is high enough so that the gravity can drain the water well.
  • When digging, make sure that the trench is around 18 inches deep and 9 to 12 inches wide.
  • If the trench is small, you can use a shovel to dig it. For larger trenches, it is better and faster to go to a trencher rental instead.

Step 3:  Trench Lining

To prevent dirt, slit, and tree roots, line your trench with a water-permeable filter fabric. You can also lay a weed barrier over the gravel bedding in the trench to keep it clean. At the same time, it also helps mitigate excess clogging of pipes as well. Make sure to leave the filter fabric open with at least 10 inches of excess fabric at the sides. This is to keep it in place and ensure that the speed and weight from the water do not change its position.

Step 4: Gravel Bedding

Next, pour the gravel or landscaping stones into the bedding on top of the filter fabric along with the trench. The gravel should be around 3 inches, and make sure to compact them in place. It works as bedding for the drainage piping, and this step is necessary, so don’t skip it.

Step 5: Pipe

First of all, connect your pipes together and make sure to secure all the fittings to prevent leaking. Choose your pipes wisely because digging them up and changing them take a lot of time and energy. I recommend investing in durable pipes that are a little pricey that you can use for years to come. PVC pipes are durable and long-lasting and don’t forget to drill holes for excess water escape. In case the drain is not in a straight line, choose a flexible drainage hose but make sure it is durable.

Then lay the pipe structure that you connected in the trench on top of your gravel bedding. Don’t forget to align the drainage holes in the perforated pipe downwards. You can pour water into the inlet grate to test the flow of the drain before moving on to the next step.

Step 6: Pipe Coverage

The next thing to do is cover the pipe with another 3 inches of gravel or landscaping stones. Then wrap the excess filter fabric that you left in Step 3 over the gravel for another layer of protection. Once everything is done, you may fill the trench with topsoil then compact it to cover the entire system. You may add some good-looking stones on top of it for a nice look if the system is visible.

Step 7: Maintenance

Inspect the inlet grate and outlet point regularly, especially after heavy rain or storm. This is to make sure that everything works well and you can fix it on time if there are any issues.

For more details, the video from Home Depot here may be useful for you:

When Should You Install A French Drain?

So when do you need a French drain? This drainage system is very beneficial, and it is a great solution to various flooding problems at home. There are some certain conditions that require you to install a French drain, and those are when:

  • An open ditch is not practical or safe in your area.
  • The water does not drain from a hard surface like a patio or playground.
  • Water jeopardizes the integrity of a retaining wall during and after heavy rains.
  • There is a problem with surface water, like a driveway that washes out or a soggy lawn.
  • The water is getting into the basement after a heavy rain, storm, etc. Install a French drain when your current indoor sump pump or outdoor drainage cannot solve the issue.
  • You are rebuilding a retaining wall on a hillside because there will be a water surface issue. With a French drain, you will be able to prevent water problems from happening.

French Drain Maintenance

In order to prolong the life and performance of a French drain, you should know how to maintain it. Things are rather simple, and you can do it once in a few months or even longer, depending on how often it works. Below are a few tips on how to maintain your French drain; feel free to check them out.

Cleanup

One of the first things that you should do to maintain your French drain is to clean it. The easiest way to clean a French drain is by using a pressure washer because it is fast and powerful. This task is only required once or twice a year in order to get rid of any tiny orifice. Using a pressure washer will not damage the pipes, and it does its job really well.

In case there are stubborn clogs, then you will need to use a heavy-duty drain snake. When plant or tree roots clog the pipe, the only effective way is to use a heavy-duty snake. It is powerful, and it can break up anything in its way. You can go to the local tool rental to rent it, and they will give you want you need for the purposes.

Inspection

Apart from cleaning, you should also regularly inspect the ground in the area around your French drain. This is to look for damages and other issues if there are any, so that you can fix them on time. One of those is the accumulation of compact soil or thick layers of sediment that prevent the water flow.

Another thing to look for is the roots from trees that may go over or under the pipe. Sometimes those roots can change the pipe’s pitch, separate connections, and many other things. So if you spot roots near the drain, chances are some of them may affect the drain system. Inspect further below the ground and fix things if they are likely to damage your pipe.

French Drain – FAQs

How deep should a French drain be?

Generally, a French drain should be about 8 inches to 2 feet deep. The depth of a French drain also depends on the water issues that you are having. If the amount of water is not too much, a shallow one will definitely suffice. However, you want it to be deeper if you install it around the foundations or sub-ground living spaces. This ensures that the drainage performance is done well to channel the water out properly.

Can a French drain get clogged?

Just like other drains out there, French drains do get clogged. This issue often occurs when debris and soil build up inside the pipes. When the amount of debris or soil is too much, it can stop the water from flowing. This is why you should do regular checkups and maintenance on your French drain, especially after heavy rain or a storm. Doing so ensures that the drain works properly and well in case there is more rain or storm coming.

How can I unclog a French drain?

There are a few possible ways that you can try to unclog your French drain at home. The first thing is to use a pressure washer to run water down the French drain. It works with light clogs like debris or dirt. For stubborn clogs, use a sewer snake instead.

Wrap Up

French drains are an effective way to mitigate flooding, and they help solve numerous flooding problems around the house. So when you notice soggy lawns or grounds, maybe it is time to install a French drain at home. You can either do it yourself or hire a professional for faster and safer work. So if you wonder if French drains are worth it, you have the answer. French drains are worth it, and they can help ease drainage issues on your property really well.

Leave a Reply

Your email address will not be published.