Top 10 French Drain Mistakes & How To Avoid Them

What can go wrong with a French drain?

As a DIY’er, there are many mistakes you could make when it comes to French drain installation. Even the most seasoned DIY’ers are likely to fall into these pitfalls or mistakes.

Common French Drain Mistakes

In this article, we’ve identified a number of them including ways to avoid them. Mistakes are commonplace and not something to be ashamed of.

These mistakes enable you to avoid a repeat and do a more thorough installation job. So, are you planning on carrying out French drain installations anytime soon?

You’ll need all the help you can get as all that and more have been included here. All you have to do is read through the article for details.

About French Drains

To set the ball rolling, we provide an overview of French drains and how they function.

First off, this is a simple drain that consists of a gravel trench that covers a perforated pipe. The gravel serves as a porous material through which runoff water enters into the pipe and flows off the property.

Consider the French drain as a water conductor that helps redirect water, hence stopping it from pooling around a yard or close to a home’s foundation.

This simple drainage system helps prevent structural damage due to moisture penetration. This is as far as we’d go in explaining what it’s about.

French Drain Installation Mistakes

It’s common to find a number of mistakes made during French drain installations.

By identifying them, you’re able to avoid repeating the same. These mistakes include wrong drain rock usage, not calling to find out about buried utility lines, and also paying no attention to the slope of the area.

Additional French drain mistakes to avoid include the absence of a drain fabric, being oblivious to zoning regulations, and returning excavated soil back into the trench.

More mistakes include having only gravel poured into the trench without a drainpipe and connecting downspouts directly to the French drain.

A wrong exit point can serve as a hindrance to normal functioning. Ignoring plant roots could also serve as a problem. With these mistakes pointed out, let’s briefly discuss each of them for more clarity.

i. Wrong Drain Rock Usage

The wrong type of drain rock can cause problems to your French drain system.

Not all drain rock types are porous enough to allow free flow of water and prevent clogging of the pipes. When choosing your drain rock, it’s best to go for natural round rocks measuring between 1 and 1 to ½ inches.

Avoid small pea-sized gravel and crushed rock. All too often, people wrongly use these as their drain rock. It doesn’t take long before issues begin to develop.

ii. Not Calling About Buried Utility Lines

Installing French drains requires digging up trenches.

Now, people make the mistake of not calling to find out if there are utilities buried underground. Haphazard digging of your yard could lead to damage to such utilities which could attract costly repairs.

Examples of such buried utilities include gas and power lines. Apart from utilities, you might have to find out if there are local restrictions regarding water runoff.

iii. Paying no Attention to Slope

Slope plays a central role n determining proper drainage.

A French drain requires the proper application of gravity to function effectively. However, people make the mistake of paying no attention to the slope of their yard. Areas of no slope or negative slope should be avoided.

Also, a location with a dip or low spot won’t be ideal for French drain installation. You need a slope that slants away from your home to install your French drain.

This allows for easy flow of water away from your property.

iv. Absence of Drain Fabric

The absence of drain fabrics is one of the mistakes people make when installing French drains. Also, not every drain fabric will serve as you need to only use a non-woven type.

The reason for using non-woven drain fabrics is to help improve permeability while preventing dirt and debris from getting into the drain.

v. Being Oblivious to Zoning Regulations

To avoid having any legal issues, it’s important to focus on finding out what local zoning regulations say about this type of project.

This is one mistake people make which could lead to litigations. You might want to begin consulting with the local building authority.

vi. Returning Excavated Soil

One mistake you shouldn’t repeat when installing a French drain is returning excavated soil back into the trench after placing your drain pipes.

Remember, only permeable and porous materials need to be used. You’ll have to dispose of the dug earth and only use the right materials.

vii. Having a Gravels-Only Trench

Another mistake people make during French drain installation is the exclusion of a drain pipe.

Here, they simply cover up the trench with only gravel. This offers zero results when there’s a downpour as the water remains static and makes a mess of your yard.

A perforated drain pipe measuring between 4” to 6” should be laid and surrounded with appropriate materials like drain rock. Of course, the perforated sides of the pipes need to face up.

viii. Connecting Downspouts to French Drain

One mistake to avoid is connecting your downspouts to the French drain. Your system might not have the capacity to dump or dispose of the water quickly enough. This leads to a flooding scenario.

A better way to do this will be to provide a catch basin where water coming from downspouts collect and flow off.

ix. Wrong Exit Point

Mistakes such as wrong exit points make a French drain system to be inefficient.

Here, the general water flow direction isn’t taken into consideration. You can correct or avoid the problem by studying the water flow direction and making your installations accordingly.

x. Ignoring Tree Roots

If you have trees around your property, you’ll have to be on the lookout for tree roots during installation.

All too often, DIY’ers overlook such roots which end up causing problems like clogs and drain failures. Remember, water runs through drain pipes which is likely to attract roots.

One way to avoid this mistake is to have a material placed at the bottom of the trench. This, coupled with a layer (several inches thick) of gravel helps prevent root interactions with the drain.

These are common mistakes people make when installing French drains. With this knowledge, you’re able to avoid repeating the same. We also recommend calling a pro for problem-free installation.

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