How to install the best French drain?
Installing a French drain is a simple job that requires a bit of planning and the right materials. Start by picking a location for the drain that is sloped and the right type of pipe. Then, dig the trench for the drain and put the drain in properly so it can direct water away from your home.
How to properly add drainage to your retaining wall?
What is a Drainage System?
- Drainage Stone. All walls should include drainage stone, even if they don’t require a drain pipe. ...
- Filter Fabric. Place filter fabric * or landscape fabric above the drainage stone and below the topsoil. ...
- Perforated Drainage Pipe. The perforated pipe * should be slotted all around the pipe. ...
- Pipe Outlet. ...
How much to charge for French drain installation?
French drain cost per foot. While the average rate for piping and installation to build a french drain is approximately $25-$50 per linear foo t, the total amount may increase or decrease depending on the job’s complexity, whether you're redirecting interior or exterior water and what kind of piping you use. Total linear feet.
How to do drainage for a retaining wall?
- Base First, a retaining wall must be built on a suitable base. ...
- Backfill Second, a retaining wall must have properly compacted backfill. ...
- Drainage Third, since most retaining walls are impervious, which means water cannot pass through the wall itself, efficient drainage is crucial. ...
Do I need a drain for my retaining wall?
Retaining wall drainage is critical. It ensures water does not collect behind the wall, causing it to fail. A quality drainage system collects and redirects rainwater away from the wall. It decreases pressure on the soil around the foundation and within the wall itself, reducing erosion and settlement.
What do you use for drainage behind a retaining wall?
gravelFor proper drainage, the first 12 inches of space behind a retaining wall should be filled with crushed stone or gravel. This is so that when water gets into the space, it does not become bogged down in soil but instead can flow down the wall to the drains or weep holes.
How do I know if I need a French drain?
You'll know you need a French drain if water is an issue in your house. The most common problem is water getting into your basement. Also consider a French drain if standing water outside of your home is an issue.
How deep should a French drain be behind a retaining wall?
French drain depth: About 8 inches to 2 feet deep should be sufficient for many water-diverting projects, though related systems, such as those built around foundations and sub-ground living spaces, as well as the bases of retaining walls, may be deeper.
What is best to put behind a retaining wall?
In order to provide proper drainage, at least 12 inches of granular backfill (gravel or a similar aggregate) should be installed directly behind the wall. Compacted native soil can be used to backfill the rest of the space behind the wall.
Should you put plastic behind a retaining wall?
I always run the thicker black plastic behind retaining walls. Preserves the timber sleepers a bit more and stops dirt and weeds coming through the inevitable gaps. +1 for geotex on the ground and up the soil you want to retain, then aggregate between fabric and wall, with drain at the bottom.
What is the alternative to a French drain?
Swales or Valleys Swales, also called valleys, are an alternative to French drains that capture and divert rainwater. Swales are shallow ditches that do not contain pipes. You can usually find them along a property's edge, following the natural grade of the land to direct runoff to ditches or wooded areas.
Is it worth it to install a French drain?
French drains help prevent flooding and reduce the risk of long-term water damage to your property. They can last between 30 and 40 years. They're cost-effective. French drains can be aesthetically pleasing as they are usually covered with small rocks, plants and sometimes even decorative grates.
Do landscapers put in French drains?
The landscaping construction company who installs your French drain needs to make sure the proper slope is determined so water flows continuously and consistently to the pop-up valve or exit. Another common failure is the pipe perforations become clogged with dirt and debris.
Where should a French drain be placed on a retaining wall?
If you're building a retaining wall, add a French drain behind the first course of stones or blocks. Otherwise, water moving down the hill will build up behind the wall and undermine it. The pipe should rest on the same compacted gravel base or concrete footing that supports the wall.
Does a 12 inch retaining wall need drainage?
Gravel Backfill Do you need drainage behind a retaining wall? Yes, which means you need backfill too. This backfill is the soil that's located in the first 12 inches of space right behind the retaining wall in order to have proper drainage, and it can be either gravel or crushed stone.
Do retaining walls need weep holes?
Weep holes are small, evenly-spaced holes along the bottom section of your wall. They protect the structural integrity by allowing underground water to seep through, preventing pressure build-up. Every retaining wall should have them.
How do you waterproof the back of a retaining wall?
0:424:36How To Waterproof A Retaining Wall - YouTubeYouTubeStart of suggested clipEnd of suggested clipOr an above ground area where it's going to be visible. So there's always voids.MoreOr an above ground area where it's going to be visible. So there's always voids.
How do I stop water from coming in my retaining wall?
How to Prevent Water From Seeping Through Retaining WallsApply LIquid Waterproofing Membrane. ... Allow the Membrane to Cure. ... Measure the Retaining Wall's Length. ... Add a Layer of Gravel. ... Position the Perforated Pipe. ... Connect Drainage Pipes. ... Cover the Pipe With Gravel. ... Cover With Dirt.
What kind of fabric should I use behind a retaining wall?
Landscape fabric is thin and sturdy and is a simple way to preserve a retaining wall's construction.
Does gravel around foundation help drainage?
Gravel Beds Provide Natural Drainage In order to get the best drainage results, the soil must slope away from the foundation. If you build on a slope and you have a gravel bed, you will basically have a natural irrigation system that runs all the groundwater down and away from the building.
What is the backfill for retaining walls?
Backfill simply refers to the soil directly behind the wall. For proper drainage, the first 12 inches of space behind a retaining wall should be filled with crushed stone or gravel. This is so that when water gets into the space, it does not become bogged down in soil but instead can flow down the wall to the drains or weep holes. Many designs allow for the top six inches of space behind a wall to be filled with native soil, so that the area can be used for planting.
Why is drainage important for retaining walls?
Why Proper Drainage is Important for Retaining Wall Performance. A retaining wall is built to hold back a certain amount of soil. The design of a properly-built retaining wall resists the force of the soil behind it and prevents caving, buckling, or leaning. However, retaining walls are built with a certain capacity in mind.
What is a weep hole?
Weep Holes. Weep holes are openings in the front of the wall that allow moisture to escape. They may be positioned at the base of the wall for structures with minimal need for drainage, or in a grid pattern across the entire wall. Water flowing from weep holes can create unsightly stains if the retaining wall material is not properly protected, ...
Why do retaining walls fail?
Retaining walls are useful and attractive features in many yards, but they are prone to failure if proper drainage is not considered. Some professional installers find that nearly 80 percent of the retaining walls they see fail at some point due to improper drainage. Whether you are planning to install your own retaining wall or have someone else ...
Why is compaction important?
Soil compaction is most important for creating strength , but it also makes the dirt less permeable and reduces the ability of water to seep into the space behind the wall. The soil behind the layer of gravel backfill is the target for this step.
What happens when water gets behind a wall?
When water gets behind the wall, it puts additional pressure on the structure, which can result in the overall force exceeding the wall’s ability to resist. This is what good retaining wall drainage looks like: When the wall is no longer able to resist the force behind it, the weakest part will give.
Why does a wall buckle?
In other cases, water pressure behind the wall may cause it to lean outward. If the pressure is consistent and forceful enough across the wall, it may even buckle.
Why Do You Need Drainage in the First Place?
A retaining wall’s mission is to hold back soil and help prevent leaning, caving, or buckling. However, if you happen to have too much water behind the wall, this will cause the wall to lean, cave in, or buckle from all of the pressure. When this happens, it will develop in the weakest spot of the retaining wall. Make sure to remember its importance while planning your outdoor living.
What are weep holes?
Weep Holes. These openings at the front of the wall are necessary to let moisture escape. Depending on the drainage need, they can be either at the base of the wall or in a grid pattern all across the whole wall.
Where is the toe drain located?
While tall walls need multiple pipe drains at different heights, most pipe drains are located at the base of the wall , vented every 30 to 50 feet.
Can you backfill a wall with native soil?
Also, it’s possible to fill the top six inches of space with native soil, which allows you to design a garden and use the area for planting.
What is a retaining wall?
Usually constructed from pavers, concrete blocks or other solid, stackable materials, retaining walls create a barrier against which soil rests, turning a sloped yard into one or a series of flat surfaces. This makes gardening much more feasible than trying to do it on an erosion-prone slope. Because retaining walls keep soil in, however, they also ...
Why do people build retaining walls with sand?
These days, many people choose to build their retaining walls with a layer of sand packed up against the stones to create a buffer between the soil and wall. Gravel also works, though anything coarser than the soil in your garden puts the drainage layer at risk for clogging and failing.
Why do retaining walls have weep holes?
Helpful Holes. Because of the danger of allowing water to accumulate, most retaining walls have built-in drainage mechanisms. Sometimes this means a pipe running through the wall from the soil to the other side, called a “weep hole.”.
How to reduce water runoff?
Because a lot of erosion occurs due to rain running over the surface of soil, you can reduce water runoff by planting groundcover and surface-rooting plants that anchor soil and use moisture. If, however, you still have plenty of water that moves down the slope, you will need to ensure you give it ample draining room.
Can you tame a sloped yard?
If you suffer from the gardener’s nightmare of an unlandscaped sloped yard, never fear: You can tame the beast with retaining walls. While they are simple to install, however, you must be careful to allow proper drainage, as a buildup of water can be both destabilizing and potentially dangerous. Holes in retaining walls are just one of the ways water pressure can be released.
Who is Sarah Moore?
Sarah Moore has been a writer, editor and blogger since 2006. She holds a master's degree in journalism.
