Levi Reeves - May 5, 2023

French Drain Fabric - What you Need to Know

AFrench drain is a drainage system designed to redirect water away from a particular area, usually around a building's foundation or in a low-lying section of a yard.

The French drain consists of a trench that is filled with gravel or rock and a perforated pipe wrapped in a fabric filter that is laid on top of the smooth rock.

When it rains or when water accumulates in the surrounding soil, it flows into the trench and through the rock and the perforated pipe, which then directs the water away from the area where it is not wanted. The water is usually directed towards a natural slope or a sump pump that pumps the water away from the property.

French drains are often used in areas where water accumulation can cause damage, such as basements, crawl spaces, and foundations of buildings. French drains can also be installed in yards to prevent standing water and soil erosion.

Quick Summary

What is it?
French Drain Fabric is typically lighter weight non-woven geotextile fabric.

Why use it?
The fabric helps to keep debris and sediment out of the french drain pipe.

How to install it?
First start by digging the drainage trench. Next remove debris from the area such as rocks and sticks. Lay the fabric in the trench followed by the drain pipe. Finally wrap the pipe in the fabric and then cover with washed drain rock.

French Drain System Benefits

Preventing water damage: By redirecting water away from areas where it can cause damage, French drains can protect buildings and other structures from water damage.
Reducing soil erosion: French drains can prevent soil erosion by channeling water away from sloping areas and preventing soil from washing away.
Preventing mold and mildew: By reducing moisture levels, French drains can help prevent mold and mildew from growing in damp areas.
Increasing property value: A well-maintained French drain system can increase the value of a property by protecting it from water damage and maintaining its structural integrity.

Importance of French Drain Fabric

French drain fabric, also known as non-woven geotextile fabric or drainage fabric, is the key component of a French drain system that surrounds the perforated pipe to ensures its effectiveness.

The fabric used in French drain systems plays an important role in ensuring the longevity and effectiveness of the drainage system. It acts as a filter to prevent soil and debris from clogging the perforated pipe, while still allowing water to pass through freely. This allows the system to function properly and ensures that the water is redirected away from the area where it can cause damage.

In addition to preventing clogging, the fabric also helps to keep the soil around the drainage system stable. This is because the fabric regulates the flow of water to some extent, preventing the soil from shifting or collapsing around the perforated pipe.

In this article, we will cover all the details about the drainage fabric to help you realize how it is necessary for your drainage system. We will also discuss the different types of drain fabric and their unique features. We will also explore the benefits of using this fabric in your drainage system.

French Drain Trench Digging

French Drain Fabric

You're building a french drain and aren't interested in redoing the drain every couple of years? Better get the right fabric! Our french drain fabric is a random pattern needled punched fabric made of 100% polypropylene. Designed to let the water through and keep dirt and debris out. Because this is commercial-grade fabric it's going to hold up a whole lot better then that stuff you'll find down at the garden center in the bargain bin.

View our Heavy-Duty French Drain Fabric

Backyard Drainage Issue

What is French Drain Fabric?

French drain fabric is a special type of geotextile fabric that is used to surround the perforated pipe in a French drain system. It acts as a filter to prevent soil and debris from clogging the pipe, while still allowing water to pass through freely.

One of the key characteristics of nonwoven fabric is its permeability. This means that it allows water to flow through it while retaining soil and debris. The permeability of the fabric is crucial to the effectiveness of the French drain system, as it ensures that water is properly redirected away from the area where it can cause damage. Other characteristics of drain fabric are listed below:

High tensile strength: Drainage fabric has a high tensile strength, which means that it can withstand a significant amount of stress or tension without breaking or tearing. This is an important characteristic because the fabric must be able to maintain its integrity even when it is subjected to heavy loads, such as soil or rocks.
Rot-resistant: Drain fabric is typically made from materials that are resistant to rot and decay, such as polypropylene or polyester. This is an important characteristic because the fabric is subjected to moisture and organic matter all the time. If the fabric is not resistant, it will break down. Rot-resistant fabrics ensure that the French drain system remains effective for as long as possible.
Resistant to chemicals: This fabric is resistant to a variety of chemicals, including acids, alkalis, and oils. This resistance ensures that the fabric remains effective even when it is exposed to potentially harmful substances.
Flexible: Non-woven fabric is relatively flexible, which makes it easy to wrap around the perforated pipe and conform to the contours of the trench.

This fabric is also available in a variety of thicknesses and weights, depending on the needs of the specific drainage system. Thicker, heavier fabrics are typically used in areas with heavier soil loads, while lighter fabrics are suitable for areas with lighter soil loads.

Types of French Drain Fabric

Drainage fabrics can be classified into two main types based on the materials and construction: non-woven geotextile fabric and woven geotextile fabric. However, it is essential to note that woven geotextile fabric is not recommended for French drains.

Non-woven Geotextile Fabric
This type of fabric is ideal for French drains due to its excellent permeability, which allows water to flow through easily while preventing sediment from clogging the drain. Non-woven geotextile fabric can be further classified based on weight:

Drainage System Installation

Lightweight non-woven geotextile (4 oz): This fabric is suitable for light-duty drainage projects, providing adequate filtration and separation.
Medium-weight non-woven geotextile (6 oz): This fabric is ideal for more robust French drain systems, offering increased strength and durability compared to the lightweight option.

Woven Geotextile Fabric
Though not ideal for French drains, woven geotextiles have high tensile strength and ground stabilization properties, making them suitable for applications like gravel pavement construction and stabilization. However, their lower permeability compared to non-woven geotextiles makes them less suitable for drainage projects like French drains.

Drainage System in Backyard

Material and Construction

French drain fabrics, also known as geotextiles, are made from different materials, primarily polypropylene and polyester. These materials have specific characteristics that make them ideal for use in drainage applications.

Polypropylene
French drain fabrics made from polypropylene are non-woven, meaning the fibers are arranged randomly and bonded together through a heat treatment or needle-punching process. This type of fabric offers excellent filtration and separation properties.

Benefits: Good resistance to ultraviolet light, rot, and chemicals. Provides effective filtration, separation, and drainage. Lightweight and easy to handle.
Drawbacks: Lower strength and durability compared to other materials. May require additional protection against punctures.

Polyester
Polyester is another synthetic material that offers excellent durability and resistance to moisture, chemicals, and UV rays. Like polypropylene, polyester French drain fabrics are also non-woven, providing excellent filtration and separation properties. In some cases, woven polyester fabrics are used for more robust and demanding applications.

Benefits: High strength and durability. Resistant to rot, mildew, and chemicals. Provides excellent filtration and drainage. Can withstand high loads and stresses.
Drawbacks: More expensive than other materials. Less effective in very wet conditions. May require special installation techniques.

Nylon

Benefits: Extremely strong and durable. Resistant to punctures, chemicals, and abrasion. Provides excellent filtration and separation. Can withstand high loads and stresses.
Drawbacks: More expensive than other materials. Less effective in wet conditions. May require special installation techniques.

Geotextile Wrapped Around Drainage Pipe

Drainage System Installation

The Benefits of Using French Drain Fabric

Here are some benefits of using non-woven fabric:

Enhanced drainage performance: It is designed to allow water to flow through while filtering out sediment and debris. By placing this fabric around the drain pipe and in the trench, the soil is prevented from clogging the pipe and reducing its drainage capacity. This ensures that the water is efficiently directed away from the area, reducing the risk of water damage or erosion.
Reduced clogging and soil infiltration: Without drainage fabric, soil particles can infiltrate the drain pipe and reduce its effectiveness over time. This can lead to clogging and even complete failure of the system. The fabric provides a physical barrier that prevents soil infiltration and ensures consistent drainage performance.
Protection against sediment and debris: Sediment and debris can accumulate in drainage systems over time, reducing their capacity and increasing the risk of clogging. The fabric acts as a filter to trap sediment and debris and prevent it from entering the drain pipe.
Extended lifespan of the drain system: The use of drain fabric can help to protect the drain pipe from damage due to soil infiltration, sediment accumulation, and clogging. This can extend the lifespan of the drain system, reducing the need for expensive repairs or replacement.

How to Use French Drain Fabric

Here is a step-by-step guide on how to use geotextile fabric:

Preparation and Planning: Before installing the drain fabric, you need to plan and prepare the site. Here are the steps involved in preparation and planning for the installation of the fabric:

Determine the location and length of the French drain: Identify the areas on your property where water tends to accumulate or where you want to redirect water away from your home. Measure the length of the area that needs to be drained and calculate the amount of fabric and gravel needed.
Obtain the necessary tools and materials: Purchase the required tools and materials for the installation process, including drainage fabric, perforated pipe, gravel or rock, shovels, levels, and stakes.
Prepare the trench: Dig a trench that is deep and wide enough to accommodate the drain fabric, perforated pipe, and gravel. The trench should be sloped slightly to ensure that water flows away from your home.
Compact the soil: After digging the trench, use a tamper or plate compactor to compact the soil along the bottom of the trench. This helps to provide a solid base for the fabric and ensures that it stays in place.

Installation process

Here are step-by-step instructions for installing the fabric:

Lay the fabric along the trench: After preparing the trench, lay the fabric along the bottom and sides of the trench, ensuring that it extends beyond the end of the trench by several inches. Cut the fabric to size as needed and overlap the edges to ensure a tight fit.
Wrap the fabric around the perforated pipe: Carefully wrap the drain fabric around the perforated pipe, leaving enough space for water to enter the pipe. Use landscape fabric pins or stakes to hold the fabric in place as you work.
Place the perforated pipe into the trench: Place the perforated pipe with the wrapped drain fabric into the center of the trench. Ensure that the pipe is sloped away from your home and that the fabric is facing upward.
Cover the pipe with gravel or rock: Pour a layer of gravel or rock over the perforated pipe, filling the trench up to about two inches below the surface. Ensure that the gravel or rock completely covers the perforated pipe and drain fabric.

Finished Drainage Project

Fold the excess fabric over the gravel: Fold the excess drain fabric over the top of the gravel, ensuring that it covers the gravel completely. This will help to prevent soil and debris from entering the gravel layer and clogging the drain.
Backfill the trench: Fill the remaining trench with soil, compacting it firmly to ensure that there are no air pockets. The soil should be sloped away from your home to encourage water to flow toward the drain.
Add a top layer: Add a layer of mulch, sand or decorative rock on top of the soil to improve the appearance of the drain and protect it from surface runoff.
Test the drain: Run water through the drain to test its effectiveness. Ensure that water flows smoothly through the perforated pipe and is redirected away from your home.

Maintenance and Upkeep

Once the drain fabric is installed, it is important to maintain and upkeep the system regularly. This involves inspecting the fabric and removing any debris or sediment that may have accumulated on its surface. Check the perforated pipe for any signs of blockages or damage, and repair or replace it as needed. Regular maintenance helps to ensure that the drainage system functions properly and effectively.

Downspout Connected to Drainage System

Factors to Consider when Choosing French Drain Fabric

Here are some factors to consider:

Drainage needs and soil type: Consider the type of soil you have on your property, as well as the amount of water that needs to be drained. For example, if you have heavy clay soil that is prone to retaining water, you may need a more permeable fabric that allows water to flow through it more easily. On the other hand, if you have sandy soil that drains quickly, a denser fabric may be more appropriate.
Climate and weather conditions: Your choice of fabric should also take into account the local climate and weather conditions. In areas with heavy rainfall, you will need a more durable and robust fabric that can bear the severe weather conditions. Likewise, in areas with high temperatures or strong UV rays, you may need a fabric that is UV resistant to prevent it from degrading over time.
Compatibility with other drainage components: Your choice of fabric should be compatible with other drainage components in your system, such as the perforated pipe and gravel. Ensure that the fabric you choose is strong enough to support the weight of the gravel and prevent soil infiltration into the gravel layer. Additionally, consider the type of pipe you are using and ensure that the fabric is compatible with the pipe material and size.

Challenges and Limitations of French Drain Fabric

While geotextile fabric is a popular and effective solution for managing excess water on your property, it is not without its challenges and limitations.

Potential for clogging and soil infiltration: While drain fabric is designed to prevent soil and debris from entering the drainage system, it is still possible for the fabric to become clogged over time. As soil particles and organic matter accumulate on the surface of the fabric, they can impede water flow. Additionally, if the fabric is not installed properly, soil can infiltrate the gravel layer and cause clogging from below.

Conclusion

In conclusion, French drain fabric is a critical component of any effective drainage system, helping to prevent soil infiltration, clogging, and debris buildup. By choosing the right fabric and properly installing and maintaining your French drain system, you can ensure that your property remains protected from the damaging effects of excess water.