Excess water buildup can quickly destroy your yard and damage your property without an efficient drainage solution in place. French drains and trench drains are two of the most popular options used within residential and commercial properties alike. The two concepts are not interchangeable.
For instance, French drains are designed to focus on moving water within a piping system while trench drains control water using trenching & material. Knowing the design and functions of each will help you to decide which of these drainage solutions is the best match for your specific property needs.
How Do French and Trench Drains Work?
Below is an overview of how French and trench drains work in addition to other important facts to consider about their design:
- Uses gravity to carry rainfall away from area & down a PVC pipe located in slightly sloped “trench” towards designated exit point.
- Needs occasional maintenance to ensure piping is clear and flowing
- Typically lasts 8-10 years before repairs or replacement is needed
- Uses gravity to carry water away from pooled locations
- Mostly used in commercial industries – such as agriculture and public planning
- Must consider run, slope, and width in overall design
- May need to add neutral channel trench train depending on area pitch
Focus on the Slope of the Yard
A key factor in the decision-making process should be any applicable slope in your yard. For instance, if your yard slopes away from the foundation, then a French drain would be problematic. A trench drain will work much better.
Consider Rainfall Frequency & Flood Risk
You should also consider the frequency and severity of rainfall in addition to the risk of flooding before selecting a drainage system. French drains work well with soil that encounters frequent saturation from rainfall and areas with a high flood risk.
What Are the Advantages of French and Trench Drains?
A French drain is very affordable – especially when compared with other landscape drainage systems. These drains also work hard to successfully take your lawn from a soggy swamp to beautiful yard ready for planting gardens and flowerbeds.
You also can select if you want the excess water to flow to an interior or exterior draining system. This will help to prevent any potential foundation water damage that may occur over time.
Trench drains offer the advantageous design of a wide channel, which effectively prevents standing water and clogging issues. Backflow and spills are prevented by their high flow capacity.
They also offer a rounded bottom option designed to minimize risk of bacterial buildup within the drain channel. Trench drains are also popular choices when it comes to the overall drainage of solid materials.
What Are the Disadvantages of French and Trench Drains?
There are several disadvantages of both French and trench drains to consider as well. For instance:
French drains have a high risk of eventual clogging due to the progressive damage caused to the perforated piping or weeping tile.
Additional clogging issues could be caused by erosion that allows muddy water to invade the pipe and progressive sediment buildup.
Since it is underground, you also need to focus on the dangers involved with the installation process – specifically when it comes to nearby water lines, communication lines, or powerlines.
You must also calculate the cost of removing any porches, structures, or sidewalks that may need to be temporarily relocated during the installation.
Just as the perforated pipes of French drains can become problematic, the grating of trench drains could also create issues over time. For instance:
Bacteria can grow within the grates – which also increases the risk of odors and contamination. Another contamination risk is the splashing created by the high flow rates within the drain.
The grates could also experience damage on industrial sites from construction equipment and forklifts.
A possible safety issue is the trip hazard that could be created by the grate-covered openings.
Analyzing the Materials Used to Make French & Trench Drains
Most French drains are made from perforated pipes. However, its effectiveness comes from the elements that surround it – namely, sand or gravel.
Landscaping textile is typically used to secure the gravel or sand in place in addition to preventing the roots and soil from invading or clogging the pipe. However, you should never make the mistake of assuming that the landscaping textile is all you need in lieu of the gravel or sand.
On the other hand, a variety of different materials can be used to create trench drains – such as galvanized steel, plastic, and cast-iron grates. The customizable design makes it easy match most settings and scenarios depending on the needed use.
For example, you would need a much higher quality substructure and grate when designing a drain for a busy roadway compared to a nature park.
Which is the Easier DIY Project – French or Trench or Drain Installation?
It is possible for you to install a French or trench drain solution yourself as a DIY project. Below is a brief overview of the steps that would be involved for each:
Plan the location based on where the excess water pools. Dig a trench to your selected outlet after checking for underground PVC pipes and utility lines. The trench should be between 18” deep and up to 12” wide. Create a slight slope to ensure that gravity will do its job.
Line the trench with water-permeable filter fabric or weed-preventing landscaping and pour the gravel or sand bedding into the fabric. You would then connect the pipes, set & secure the pipe drain, cover it with the fabric or gravel/sand, and then backfill the trench with topsoil.
Dig for the trench train. Keep it at least 4” on each side, clear the debris, and then create a one-inch layer of compacted gravel. Locate the catch basin and start to lay out the drain channel.
Identify the appropriate channel height (which is a crucial step) and then backfill your trench with at least 4” of concrete on each side. Remove the tape once the installation is complete.
Between the two, French drains are easier and more DIY friendly. The material required is more cost effective, and the installation process considerably easier.
However, the ease of install is dependent upon your DIY capabilities. This type of project is recommended for people with a moderate amount of landscaping or DIY skills.
Considering all the factors and variables involved, it is understandable if you decide to hire a professional team that specializes in landscaping services. The best approach is to weigh all of your options and the specific needs of your property.