Does a French Drain Need an Outlet?

So you’ve just bought a house in the suburbs, and decided to replace your old-fashioned sump pump system with a new, state-of-the-art french drain. The problem is that you’ve heard that french drains need an outlet in order to function.

A common concern by many people is if this is true. A french drain does not need an outlet if it’s properly installed.

French drain is one of the most common types of drainage systems that I see around a lot. It’s a trench filled with gravel that diverts water around your house foundation using a buried perforated pipe.

The water will simply permeate into the ground as it moves along the pipeline. In fact, from what I know, you don’t need to have an inlet on just one end of a French drain pipe. You can construct the drain to accept water along its entire size, and distribute it underground.

A french drain is used to remove water from a low-lying area and keep it from getting muddy. 

If it has outlets, it is used to lower the water level in the drain whereas a non-outlet french drain is used to remove water from the area.

Now, if you reside in a city like I do, it is safe to have outlets because there would be an existing network of electrical cables running through your neighborhood and connected to your house.

Should a French drain have standing water?

Whether you have a septic system or a sewer system, a french drain to me is a great way to manage excess water.

If you have a French drain on your property, you might wonder if the drain should have standing water. The answer is no, but only if you want the drain to work correctly. 

Water is used to help keep the soil under your home porous and loose so that it can drain properly. However, if the water collects, it will not only stagnate, but the resulting pool of water will cause your foundation to buckle over time. 

Remember that a French drain is a trench that allows water to flow away from your home and into an open channel or pipe.

Why would you want a drain that has standing water? Right?

Apart from preventing basement flooding, I should say, using French drain to divert surface water from a site can also improve the appearance of a lawn or garden, by keeping it dry. 

Common causes of standing water over French drain

Have you ever looked at a French drain and wondered why pools of water form above it?

There are a few reasons for this.

  • First, you need to consider the type of soil on the drain. If the soil over the drainpipe doesn’t allow water to seep through it conveniently, the water will certainly puddle up until it slowly drains pipes via the soil. A very dry sand soil may not be loose enough and will also take time for water to filter down.
  • Another reason could be the slope. The drain requires enough pitch to drive the water away.
  • You should also pay attention to the compacted dirt after digging the trench. It may cause the issue of puddles not going away quickly.

To combat these problems, here are key considerations before installing a french drain:

  1. Regarding French drain pipe depth, 8 inches to 2 feet deep is sufficient for numerous water-diverting tasks, though associated systems, such as those built around structures as well as sub-ground homes, in addition to the bases of preserving wall surfaces, might require a little more depth.
  2. The size of the gravel used in the drain aggregate can vary from pea gravel to bigger pellets of river rock. If there’s going to be piling of different sizes, then, smaller pieces normally go closer to the pipeline, while bigger items sit closer to and externally.
  3. The pipeline needs to be sufficiently long to carry water from the below ground areas where it collects to an end point.
  4. Slope is a major consideration in keeping a constant flow of water, as is the aggregate positioning as well as surrounding material to avoid debris from obstructing the pipeline.

How do I know if my French drain is working?

When my friends are having a problem with water pooling in their basement or the sump pump running more than it should, I know they might be suffering from a drainage problem.

The most common drainage problem around homes and businesses is when the ground around the foundation starts to sink, causing water to back up against the foundation walls. 

Installing a French drain in your yard is one thing, but knowing if it’s working is another. 

The key is making sure that after installation, it’s properly maintained. 

Otherwise, your drainage ditch could be clogged or not deep enough, allowing water to seep into your house and basement.

The best way to tell if it’s working? Water should always flow away from your house to an area away from your foundation. 

The trench in turn drains into a pipe that leads to a dry well, a water-tight pit filled with gravel or crushed rock that has an outlet to the sewer.

If water stops flowing away from your house, then you may need to replace your French drain. 

And in case your French drain is filled with sludge or debris, then you’ll want to call a professional to replace the drain and clean the area if you have no idea of how to inspect it.

Can you do a French drain without a pipe?

Many homeowners that I come across choose to do a French drain by themselves as it is a relatively cheap and effective way to solve severe basement flooding.

Others use the system to remove water from swimming pools, bathtubs and sinks.

But what you might not know is whether French drain channels water away with or without a pipe.

One way of creating a French drain is simply using gravel without any pipeline work. 

The water just gathers in and is transported within a gravel or rock loaded network that starts from the surface or just below it. 

But in contemporary times, a functional French drain will certainly consist of a drainage pipe installed within a gravel channel.

Final thoughts

People are always confused about what the purpose of an outlet is, and I think they’re often convinced that they need an outlet, when they don’t.

French drains are most commonly used after a home has been damaged by water, and are often used when a basement has been flooded. Some people wonder if a French drain needs an outlet or if it is all right to just let the water drain away from the house.

After all, the French drain is designed to keep water away from the foundation of your home.

The question of whether or not you need an outlet depends on how well the French drain was installed.

When the installation is done well, the soil will simply soak up the water and allow it to flow into and through the underground perforated pipe. 

Therefore, there would be no need of setting up an outlet.

However, if you’re living in a highly populated area like a city or estate, like myself, where there could be underground power cables, I wouldn’t think twice about building an outlet for French drain.

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