Why do I need gravel in a French drain?

Nobody wants a damp lawn. After all, they can be the breeding ground of mosquitoes and is actually a sign of an unleveled property. A French drain is one of the most effective ways to solve standing water issues and aids in keeping a property dry and bug-free.

Since they do well in keeping the excess water away from homes and basements, many property owners make sure to install them for residential and even commercial use.

Building a French drain requires a trench as it is where the drainpipe will be buried into. Gravel is essential in the installation process as it helps with draining the excess water away as it seeps through the gravel faster than soil and other materials.

How much gravel should be in the bottom of a French drain?

There are a lot of things necessary in order to install a functional French drain on a certain property. As mentioned earlier, a drainpipe and gravel make the drainage system do its work, along with landscape fabric and some landscaping stones. Together, the end results will be enough to intercept the water from basements and yards and keep it that way.

When it comes to gravel, more does not necessarily equate to better. Sure, it functions to make the water easily seep through the pipe and the designated outlet. However, putting in the right amount determines the overall success of the drainage system. Putting too much gravel may block the water instead, resulting in blockage and clogs. This leads us to the question of how much is just the right amount?

Generally, many experts say that the amount of gravel that should be in the bottom of the drain should be at least a third of the size of the perforated pipe. However, depending on the type of pipe you use and the expected water flow in the area, you may need to do a trial-and-error to determine the right amount for your use.

What kind of gravel should I use?

There are a lot of gravel types to choose from. However, if the purpose is for a French drain, experts recommend using hard rock types such as washer river rocks and granite chips.

The reason for this is mainly because hard rocks are tough and break slower than other rock varieties such as sandstone and limestone. Brittle rocks will not do any good for your drainage system and you may end up digging your trench just to replace them later.

When it comes to the size of gravel, try getting bigger ones if you are not using a perforated pipe. They should at least be one or one and a half inches big. As much as possible, avoid small rocks at all costs. Not only will they be useless for your drainage, but will also cause problems such as a blockage instead.

How deep does my French drain need to be?

Technically, there are a lot of factors that will determine how deep should your French drain be. One of the most important factors that you need to consider is the water issue in your area.

As an example, if you can see pooling water on your lawn, then a shallow trench may be enough for your needs. On the other hand, if you have water entering your basement, then you will need to look into a deeper drain.

Professionals in the industry will not recommend digging your drain less than 12 inches wide and 18 to 24 inches deep. This is because they believe that the dimension of the drain is highly relative to its effectiveness. Since a deeper and wider French drain is able to accommodate more water, then it is safe to say that it will more functional if it follows the set minimum standards.

Can a French drain be covered with grass?

Is the bare appearance of a French drain not the kind of appearance you want for your lawn?

If so, you have every right to make your property look more pleasing. To answer the question, it is possible to cover your drain with grass. Many property owners do this by covering the drain with a few inches of topsoil and sod and spreading it evenly. This way, they can grow healthy grass on its surface to conceal the French drain.

Are French drains worth it?

For many professionals in the industry and by the popular opinion of property owners, French drains are absolutely worth the time, money, and effort that you will need to sacrifice during their installation.

The advantages of a French drain

1)    It can preserve your landscape

Having a functional French drain allows you to preserve the appeal of your landscape. For many owners, the appearance of their lawn can not only be for aesthetic reasons but also serves as a factor that will determine the value of their property. Because of this, owners prefer to take great care of their landscape, which will be more achievable with the help of a good drainage system.

2)    It can prevent damage to your property

Standing water and leaks can be very detrimental to the structure and condition of a home’s landscape, foundation, and basement. Since water is considered to be an enemy of most construction materials, long-term exposure can significantly decrease the stability and durability of a structure and even encourages mold to appear.

3)    It slows down erosion

Due to common reasons, soil erosion is bound to happen in every property due to weathering and unstable soil. However, the rate of erosion may be higher for some properties because of the lack of proper drainage channels. Having a French drain can allow you to reduce the soil run-off in your area.

Why do French drains fail?

Without a doubt, having a functional French drain in your property allows you to worry less about flooding, standing water, leaks, and an ugly lawn. However, like all things, this efficient system can suddenly stop working properly.

If you are in this situation, here are some of the most common reasons why a French drain may not be reliable.

Reason #1: They were not installed properly

For those with no experience in digging a trench or installing utilities, French drain installations can be a nightmare. Hence, DIY drains are more prone to fail compared to professionally installed ones.

There are a lot of things that must be considered during the installation: from the soil in the property, the right materials to use, the positioning of the pipe – that can be too much for the average homeowner. Because of this, if you are planning to have an efficient drainage system, hiring an expert may be the best decision you will ever make for your property and your wallet.

Of course, if you prefer to install the system yourself, then it is up to you. Just make sure to do extensive research and inspect your area thoroughly in order for you to see which parts have high water tables. Always remember: the key to a long-lasting French drain is a well-executed drain installation.

Reason #2: The pipe may get clogged

Aside from poor installation practices, another reason why French drains may fail can be due to a clogging issue. Usually, this happens when the water from the rain or other sources sticks into the pipes and the gravel instead of traveling towards its ideal path.

This is also the case when muddy water gets into the French drain. As soil and sediments build up in the pipes, the result will be a clog that will need to be addressed as soon as possible. If you want to determine if your drain is clogged, do some inspections around your property. You can do this by checking your yard for standing water and soggy soil. In some instances, your basement walls and foundation may be wet due to the condensation.

If you are in this situation, try doing maintenance on your pipe. Just insert a garden hose and let the water unclog the dirt by setting it on full blast.

Reason #3: They may be invaded by roots

Since French drains are usually buried underground, there is a high chance that tree roots may invade your pipe. This results in a blockage that could be the reason why your drainage system is not working. Once standing water is on your lawn or pooling on your foundation, this can be the case if you have a tree around your property.

Because of this possibility, you should watch out for trees that spread their roots extensively, such as a maple tree. Since the roots are in a quest to find nutrients and water, they may find your French drain to be a good place to infiltrate.

Reason #4: They may require assistance from a sump pump

In some extreme instances, your situation may not be handled by just the installation of a French drain. If your existing system is inefficient despite being well-maintained and properly installed, you should probably accept the fact that not all water can be channeled away by just one drainage system.

Because of this, you may also need to install a sump pump pit. Sump pumps are motor equipment that needs electricity to work. They can assist your French drains during heavy storms as they can route the water away from your home and into the designated pipe system.  Doing this allows you to remove the excess water from your basement and keep it that way for a long time.