Installing a French drain can be a great landscaping solution for you if your backyard is wet, and unusable. That being said, there are many problems that can arise while thinking about putting in a French drain system, and having one installed.
Here are some of the top 10 problems with French drains:
#1. Backfilling the drainage pipe with dirt
When backfilling a French drain, it may seem like a good option to use the dirt that was dug up so that you do not need to worry about where to dispose of it. The problem with using the excavated soil is that native clay does not allow water to go through it. When you backfill with dirt, no fabric is placed in the trench, and when there is no fabric in the bottom of the trench and encapsulating the drain pipe system, soil will end up in the pipe. This means that even if water eventually makes its way through the clay soil and into the system, the likelihood of the drain pipe clogging is high, and the water will still have nowhere to go.
#2. Contractors or clients wanting to save money
With the cost of living and housing, it is no wonder homeowners do not want to spend their hard-earned money on a french drain installation instead of a vacation. French drains that may have a higher price usually have a more durable pipe that does not crush, and fabric encapsulating the trench to keep the soil from mixing with the rock in the system. Large rock is used to create void space in the trench, which dries out the system. This system will last a century, while a lower cost version will last 2-24months.
#3. No original drainage system
Surprisingly enough, when new homes are built, yard drains are not included. These systems are looked at as “extra” by municipalities and builders. In our wet climate with excessive groundwater it really should be mandatory to install a drainage system for some properties and avoid altogether the drainage issues that inevitably occur.
For people living on these properties without a drainage system that live at the base of a hill, or have their neighbors above them, their yard is only going to be useable for only about half of the year due to an inundation of surface water runoff in the yard. Without a system, their grass may be unable to grow, and the space can be unusable for pets, and children. When people buy a house, they want a useable yard and nobody wants to be dealing with drainage problems and excess water in their awesome new place! This is something to be aware of when moving into a house, new or old.
#4. Underestimating how much rain the Fraser Valley gets
The Fraser Valley averages 174 rainy days per year. Heavy rains and stormwater is a real issue where we live and it results in a lot of excessive groundwater! If you do not have a French drain pipe system, put in in your yard, you will most likely need to wait a day if not more, to be able to use your backyard space. This means having to wait to mow your grass, being unable to BBQ, and keeping children and pets inside.
It can be frustrating having to postpone your weekend plans because it rained the day before and your yard has yet to dry out. This is especially annoying if you have a day off and are trying to do yard work. Luckily, if you put in a French drain pipe system not only will you be able to enjoy your yard much sooner than others, you will be able to use it for longer periods of time. This is where having a French drain pipe system really pays off.
#5. Ignoring 25% of your lawn drainage solution
Putting in a French drain pipe system is a 75% solution for your backyard drainage. The first part of the solution is to have a French drain installed. The second step, to think about is growing healthy grass, with healthy roots. Healthy roots from grass, plants and vegetation are what help the water pass through the clay soil in your yard. If you are noticing that a French drain you have already installed is not getting enough of your yard dry, try getting your grass to grow, or mow higher, and see if this makes a difference.
#6. Using untested fabric, and not encapsulating the entire system
One of the reasons that fabric is used in a French drain install is so that the soil does not get into the system and mix with the gravel. One problem with using some kinds of landscape fabric is that the water pools on top of it if it. When this happens, the water never has a chance to get into the drain pipe, and be taken to its discharge. Before using any fabric in your French drain pipe system, it is important to know if the manufacturer specifications of the fabric are correct.
We tested filter fabric that stated that it could move up to 95 gallons of water per min, per square ft. This fabric did not do what the specifications stated, and the flow of water pooled in our test pail. Some people choose not to use fabric for this reason. Luckily, there is fabric out there that can keep up with the water flow, you just need to make sure to test it first.
The reason it is important for fabric to encapsulate the entire trench is that once done, no soil can get into the gravel, and your trench will last centuries. If the fabric used does not line the bottom of the trench, as well as the sides, and top, the soil will mix with the gravel. Once this happens, you are putting an expiration date on the system, and it will eventually clog.
#7. Not digging the system deep, or wide enough
When digging a trench for a French drain pipe system the deeper and wider that the trench is dug, the more surface area there will be within the trench. This is important, as the surface area of the trench dries out the subsurface.
Other factors that help the subsurface stay dry are the rock that is used in the system. Big round rock allows a bigger void space in the trench. This air movement creates an underground drying effect. The big void space made by the rock also acts as an underground reservoir for the water entering the trench. This is particularly helpful when there is heavy rainfall or large amounts of snow melting at once.
#8. Not having a proper discharge location
City storm drains and ditches usually have enough capacity to act as a great discharge location for your French drain pipe system. If the city storm drain or ditch are at the front of your house and your system is at the back, more pipe will need to be placed to get to it. Since adding more pipe and labor will bring up the cost of the install, you may want to seek other alternatives, such as a rock pit.
Rock pits are a common method used as a discharge location, but unfortunately, they usually do not have enough space to hold the water that you are trying to get rid of. By early winter your system could get full, and will stay that way for most of the year.
#9. Cost of doing a high-performance system
A high-performance system may come with a higher price tag than a “typical” system. When using pipe that does not crush, rock instead of gravel to give more void space in the trench, and fabric to protect the trench from getting soil into it, it will last you centuries. Your family and pets will be able to enjoy your backyard any time they wish, and you will never have to worry about the system not working, a perforated pipe or having to redo it. Most importantly, having a high-performance system put in will increase the value of your house.
A complete French drain system typically costs more than people think, costing between $10,000-$17,000. A complete system includes protecting the existing landscape, installing the system, and site remediation.
#10. Not educating yourself before hiring a French drain contractor
A French drain pipe system install can seem simple enough, and may appear to be a relatively small undertaking. There are 100’s of combinations and different materials and ways that French drains can be put in and it can get quite overwhelming to see all of the options available.
It is a good idea to educate yourself before you hire a contractor, whether you know them or they were recommended by a friend or neighbor. By doing your research and understanding what system they will be putting in, and why they like to do it that way, you can feel secure in your choice to hire them.
YouTube, Google reviews, and the contractor’s website are all great resources to help you educate yourself on their scope of work, and what the project entails. It can even give you great insight on the contractor themselves!
This list of problems may see daunting but luckily, all of these problems have a solution. By hiring someone that is knowledgeable in French drains, and is able to provide you with what you are looking for, you will no doubt be able to regain your space and call it yours again.
Curious about how much a French drain costs? Click on the link to read our article, “How much does a French drain cost?”