Choosing the best solution from surface drain VS French drain is quite challenging. However, you need to pick the best option depending on the land setting and soil conditions. You might have to face occasional water damage in case you don’t make the correct decision in installing the proper drainage system. A foundation repair can cost up to $10,000 or even more, depending on the intensity of the damage. This may reduce the value of your property over time.
To prevent this, you can install a drainage system to remove the water systematically from the area. Surface drains, and French drains are two options that you can use to direct water to a distant discharging location. To find the better option, let’s compare the purpose, design, and effectiveness of the two types.
Purpose
The two types of drains have different applications. French drains are usually used to drain groundwater from near the foundations of buildings. This water is conducted to a distant location away from the foundation for discharge. French drains work best in areas with a lot of groundwater or soil that gets easily saturated from rain.
Surface drains are used to remove larger volumes of water quickly from a certain surface. It collects the excess water from a sloped surface such as driveways and drains it away immediately. It prevents water damage caused by the collection of water due to drainage issues. For example, a surface drain can prevent water from collecting around the foundation of a building with the angled installation.
Design Structure
The installation of a French drain usually needs a lot of time and labor due to its design considerations. A perforated PVC pipe wrapped in a permeable filter fabric is placed inside the trench. The French drain is backfilled with relatively fine stones. Larger stones are placed at the bottom, and the finer gravel is positioned towards the top. Since the installation is covered on all sides, plants can grow around and over it to protect the lawn from erosion.
Surface drains have a different setting with a metal grating on the level with the surface. The installation procedure is quite straightforward with simple components. This type of drain is durable due to its metal construction. You can install surface drains along with concrete areas including garages, unlike French drains.
Effectiveness
Effectiveness is a key factor in comparing a surface drain VS French drain. French drains are good at removing water from saturated soil. But it needs to have a suitable slope so that the water can drain into the basin easily. But French drains cannot remove a large amount of water within a short time. So they are less effective during floods caused by heavy rainfall. French drains also clog eventually since they are installed underground. The roots of trees can damage or displace the perforated pipes. So, French drains need inspection and replacement after a few years.
Surface drains have a higher flow rate when compared to French drains. They are less prone to clogging since the drain is simply a slope on the ground surface. Even if it clogs, you don’t need to dig up or remove the whole drain. This seems a more effective solution to keep the rainwater away from the surface near buildings. It helps remove water quickly to prevent pooling up on the ground. It eliminates a lot of inconveniences caused by heavy rains. Surface drains are also the more long-lasting solution among the two.
What Happens When Water Accumulates?
It is important to have a proper water drainage system on all premises. If not, water puddles on the land could cause various complications. If your drainage system is not effective, water pooling around the base of the building may cause the following issues.
- Water Pressure: When water builds up around the house during rain, it applies pressure to the foundation wall. This water pressure disappears after the water dries. But this increases stress on the structure due to the presence and absence of unwanted pressure.
- Construction Damage: The buildings tend to settle or even collapse when the foundation is damaged. You may find cracks in the walls and the doors or windows sticking.
- Water Infiltration: The most common issue when water pools around the house are that it penetrates into the structure. Water finds its way into the basement through cracks and crevices of the cement. You may find dampness inside the house leading to various other inconveniences.
- Interior Damage: Similar to the external damages caused to your property, water can also damage the interior. If water seeps in through the basement into the upper floors, it will damage the hardwood flooring, wallpaper, and carpeting.
- Mold and Mildew: Mold formation is prominent in dark and damp areas. This happens mostly in basements, giving out a pungent musty odor. Mold and mildew cause health issues for kids, the elderly, and people with pollen allergies.
Which is Better?
The better choice varies from one situation to another according to the individual requirements. The physical setting of the location and the ground conditions affect this. A French drain may be the better solution if:
- Water pools on the ground when it rains
- Large water puddles remain on the land after a heavy storm
- You find water in the basement after a rain
A French drain can efficiently remove the groundwater from the saturated soil to prevent it from collecting on the surface. Although it is not an efficient way to remove a lot of water at once, it can still prevent water puddles on the land.
You can install a surface drain to remove water quickly if:
- Water collects in puddles near the basement of the building
- Rainwater floods the driveways, parking areas, or sidewalks
A surface drainage system can prevent water from collecting against the foundation wall. The metallic structure of the slope prevents soil erosion and moisture ingress. Surface drains reduce complications and ensure that the land around the building is stable.
Frequently Asked Questions
What Are the Types of Surface Drainage?
Depending on various characteristics, surface drainage systems are of four types:
- Open Drains: Open drains are created by hand shovels or excavators, depending on the depth required. They remove water from shallow depressions and discharge it into drains. These are suited for flat areas and have a typical V-shaped structure with a suitable gradient to conduct water.
- Humps and Hollows: In this structure, the surface consists of parallel humps separated by hollows. This helps in removing excess moisture with the humped shapes. This installation is suitable for areas that don’t have the sufficient depth or slope of the ground. The humps could be positioned 10 – 20 meters away from each other depending on the expected amount of water to be removed. The greater the distance between the humps, the slower the water discharge rate.
- Levees: These are surface channels created with a gradient. The soil removed in creating the trench forms a levee on the downslope. The levee should be covered with grass immediately afterward to prevent erosion. This reduces the flow of water down the slope to prevent soil erosion and landslips. Levees need to have a spacing of 30 – 50 meters for slopes and a gradient of 12 – 15 degrees. These are usually established over large lands extending over a few hectares.
- Grassed Waterways: The structure consists of a shallow trench that regulates water passing down the slopes. The main use of grassed waterways is to prevent erosion. The vertical and horizontal sections should be in the ratio of 1:4. The size, and shape of the waterway determines the slope and the amount of water to be removed. The wider the waterway, the steeper the slope should be. The bottom of the waterway needs to be horizontal so that the water can spread evenly.
What is Better Than a French Drain?
The most popular alternative to French drains or any other type of passive drain system is the sump pump. It actively pumps out water to keep water from pooling. Sump pumps are usually used to prevent water from flooding the basements. The installation and maintenance of a sump pump are quite expensive as it uses both electrical and mechanical parts. A sump pump requires electricity to function, which could be a slight disadvantage. But you can use a suitable backup sump pump to remove the water even during a power outage.
How Far Away From House Should French Drain Be?
A French drain needs to be about 2 – 5 feet away from the foundation of a building. This ensures that the drain does not damage the structure but effectively engages in removing the water. Do not install the French drain in a straight line from the foundation as it may cause erosion and water pooling near the foundation. The French drain should conduct the water from the region to a suitable discharging spot at least 10 – 20 feet away from the house. It needs to have a depth of 8 – 24 inches sufficient to remove a load of water from the region.
Conclusion
You can identify the right drainage system by comparing a surface drain VS French drain. If you pick the best solution, it will prevent water from flooding your basement and pooling around the foundation. If you still cannot determine a better option, you can get a professional to examine the area and recommend a suitable water discharging method. They will also provide you with an estimate of expenses for the project.