curtain drains

Curtain Drain: A Complete Guide to Design, Installation, and Cost

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Discover curtain drains, a type of drainage system that directs excess water away from buildings like houses and other structures. This extensive manual covers every aspect of curtain drains, including their definition and use as well as the design, installation, and maintenance. Learn the distinctions between curtain drains and French drains, what influences their price, and which locations curtain drains are most frequently installed. This guide offers helpful insights to assist you in making decisions about curtain drain installation, whether you’re a DIY enthusiast or intend to hire a professional.

I. Introduction

A trench is dug around a property to direct water away from a building or other areas that require protection from excess water. This feature is known as a curtain drain or drain curtain. A curtain drain’s main function is to stop flooding or water from seeping into a building’s foundation. A curtain drain is positioned on the ground’s surface, as opposed to a French drain, which is buried. Both systems have the same function, but they differ in terms of design, installation, and operation. The definition of a curtain drain, its use, and the distinctions between a curtain drain and a French drain will all be covered in this article.

II. What is a Curtain Drain?

In order to avoid flooding or water damage to a building, a curtain drain is a trench filled with gravel or other porous materials that direct surface and groundwater away from an area. It is intended to divert water to a lower elevation or a drainage area by catching it before it reaches a building’s foundation or basement. A trench, a perforated drainpipe, a layer of gravel or other drainage material, and a layer of filter fabric typically make up the system.

Curtain drain diagram:

The diagram below shows the components of a typical curtain drain system.

curtain drain

Curtain drain system components:

  • Trench: A trench dug around the perimeter of the area to be drained
  • Perforated drainpipe: A pipe with small holes that allows water to enter the pipe and be directed away from the area
  • Gravel or drainage material: A layer of porous material that surrounds the drainpipe and allows water to flow through it
  • Filter fabric: A layer of geotextile fabric that covers the gravel to prevent soil and debris from clogging the drainpipe

III. Curtain Drain vs. French Drain

A French drain is similar to a curtain drain in that it is designed to redirect water away from a building or area. However, a French drain is installed underground, while a curtain drain is installed on the surface. A French drain consists of a perforated pipe surrounded by gravel or other porous materials and buried beneath the ground. The pipe collects water and directs it away from the building through gravity or a pump system.

Differences between curtain and French drain:

  • Installation: A curtain drain is installed on the surface of the ground, while a French drain is installed underground.
  • Purpose: A curtain drain is designed to prevent water from infiltrating a structure’s foundation or flooding an area, while a French drain is used to collect and divert water away from an area.
  • Design: A curtain drain is typically shallower than a French drain, and the materials used for a curtain drain are not buried.

Pros and cons of each system:

  • Curtain drain pros: Easier to install and maintain, less expensive, can be installed after construction
  • Curtain drain cons: Not as effective for collecting and removing large amounts of water, can be visible on the surface of the ground
  • French drain pros: More effective at removing large amounts of water, can be installed in areas where a curtain drain is not feasible
  • French drain cons: More expensive, requires more excavation and can be more difficult to install and maintain.

In conclusion, both curtain and French drains serve the purpose of diverting water away from a building or area to prevent water damage. The choice between a curtain drain and a French drain depends on various factors such as the location, the amount of water to be drained, and the installation cost. It is important to consult a professional to determine the best option for your specific needs.

IV. Curtain Drain Design

When designing a curtain drain, several factors need to be considered to ensure proper function and effectiveness. These factors include:

  1. Slope of the Trench: The trench for the curtain drain should have a slope that allows water to flow away from the foundation or the area where the water accumulation is happening. The recommended slope is about 1% or 1/8 inch per foot.
  2. Depth of the Curtain Drain: The depth of the trench for the curtain drain will depend on the location and severity of the water problem. A depth of at least 2-3 feet is recommended.
  3. Size and Type of Gravel or Rock to Use: The type and size of the gravel or rock used in the curtain drain system can significantly impact its effectiveness. The recommended size is usually between ¾ inch to 1 ½ inch in diameter. Using high-quality gravel with angular edges will allow water to flow through easily, while preventing soil and debris from entering the trench.

V. Curtain Drain Installation

Curtain drain installation can be done by a professional or as a DIY project. Here is an overview of the steps involved in the installation process:

  1. Preparation: The first step is to determine the location of the curtain drain and mark the area. Next, dig a trench with the recommended depth and slope.
  2. Install Drainage Fabric: Lay drainage fabric in the trench, making sure it extends to the sides and bottom of the trench.
  3. Add Gravel: Pour the gravel or rock into the trench, ensuring that it covers the drainage fabric and fills the entire trench.
  4. Install a Perforated Drainage Pipe: Place the perforated drainage pipe on top of the gravel bed, with the perforations facing downwards.
  5. Cover the Pipe: Cover the drainage pipe with more gravel, ensuring that it is level and evenly spread.
  6. Add Topsoil: Once the gravel is in place, add topsoil to the trench and grade the area to direct water away from the foundation.

It is essential to follow proper installation procedures to ensure the effectiveness of the curtain drain system. While it is possible to do the installation yourself, it is recommended to hire a professional to ensure proper installation and avoid any costly mistakes.

In conclusion, a curtain drain is an effective solution for managing water runoff and preventing water damage to a property’s foundation. Proper design and installation are crucial to ensure the effectiveness of the system. By understanding the differences between curtain and French drains, property owners can choose the right solution to address their specific water issues.

VI. Curtain Drain Cost

Installing a curtain drain can vary in cost depending on different factors such as the size of the area where the curtain drain is needed, the depth of the trench, and the type of material used. Here are some factors that can affect the cost of installation:

  • Size of the area: The larger the area that needs a curtain drain, the more materials and labor will be needed for the installation, which can increase the overall cost.
  • Depth of the trench: A deeper trench will require more labor and materials, and may require special equipment, which can also increase the cost.
  • Type of material: The type of gravel or rock used in the trench can affect the cost of installation, with larger or higher quality materials typically costing more.

The cost per foot of curtain drain can vary depending on the region and the type of installation. On average, the cost per linear foot for a professional installation can range from $10 to $20. The total cost for the installation will depend on the length of the trench needed.

Typical costs for different areas that need curtain drain installation can also vary. For example, a curtain drain installation for a basement may cost more than an outdoor installation due to the need for additional materials and labor.

VII. Curtain Drain Maintenance

Proper maintenance of a curtain drains is essential for ensuring it remains effective in diverting water away from the foundation of a building or septic system. Here are some tips for maintaining a curtain drain:

  • Regular inspection: Inspect the curtain drain periodically for any signs of clogging, such as slow drainage or standing water.
  • Keep the trench clear: Remove any debris, leaves, or other materials that may accumulate in the trench and obstruct the flow of water.
  • Proper grading: Ensure the surrounding area is properly graded to direct water towards the curtain drain and away from the foundation or septic system.
  • Regular cleaning: Schedule regular cleaning to remove any debris or sediment that may build up in the trench and prevent proper drainage.

Signs of a clogged curtain drain can include standing water, slow drainage, or water backing up around the foundation or septic system. If a clog is suspected, it is important to take action promptly to prevent further damage. Steps to unclog a curtain drain may include using a drain snake or hiring a professional to clear the blockage.

By following proper maintenance procedures and promptly addressing any issues, a curtain drain can remain effective in protecting the foundation or septic system for many years to come.

VIII. Curtain Drains Around Specific Areas

Curtain drains can be installed in various areas of a property to address specific drainage issues. Here are some common areas where curtain drains are installed:

  1. Curtain Drain Around Foundation Curtain drains are often installed around the foundation of a building to prevent water from entering the basement or crawl space. This is particularly important in areas with high water tables or heavy rainfall. A curtain drain around the foundation intercepts water before it reaches the building’s foundation and directs it away from the structure.
  2. Curtain Drain Around House A curtain drain around the house can protect the entire structure from water damage caused by excess water accumulation around the house. This is particularly important for houses built on slopes or in areas prone to flooding.
  3. Curtain Drain Around Septic Field A curtain drain can also be installed around a septic field to prevent water from saturating the drain field and causing it to fail. The curtain drain intercepts surface water and directs it away from the septic field, preventing excess water from infiltrating the soil and saturating the septic system.
  4. Curtain Drain for Basement A curtain drain can be installed around the perimeter of a basement to prevent water from entering the basement through the walls or floor. This is particularly important in areas with high water tables or heavy rainfall.

IX. Conclusion

Curtain drains are an effective solution to excess water accumulation problems in various areas of a property. They are cost-effective, easy to install, and require minimal maintenance. By intercepting surface water and directing it away from the property, curtain drains prevent water damage to buildings and septic systems. If you’re experiencing excess water accumulation problems in your property, consider installing a curtain drain to protect your investment.

Overall, curtain drains are a practical and effective solution to prevent water damage caused by excess water accumulation in various areas of a property. When designed and installed properly, they can prevent soil erosion, protect buildings, Basements and septic systems, and improve the overall drainage of a property. If you’re considering installing a curtain drain, it’s important to consult with a professional to ensure that the design and installation process meets the specific needs of your property.


  1. United States Environmental Protection Agency (EPA) –
  2. United States Department of Agriculture (USDA) –
  3. National Resources Conservation Service (NRCS) –
  4. United States Geological Survey (USGS) –
  5. Department of Health and Human Services –
  6. Centers for Disease Control and Prevention (CDC) –
  7. Occupational Safety and Health Administration (OSHA) –
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