How much gravel is needed for French drain?
You would need around 0.72 cubic feet of gravel per foot length of French drain for a typical French drain width of 10 inches and a depth of 12 inches if you’re using a 4″ drain pipe. How much gravel do I need for a 100ft French drain? The volume of the drain is the volume of the “box” that is 100 ft long by 6 inches by 18 inches.
What size rock is best for French drain?
We recommend putting a layer of sod and larger pieces of rock around the entrance and exit for extra protection The best gravel size for french drains is small rocks and pebbles .5″ to 1″. Gravel this size is size enough to fit in the drain lines and big enough to properly filter the water.
How to properly size a French drain pipe?
The Size of a Pipe for a French Drain
- Suitable Pipe Size. A suitable pipe for most residential French drain systems has a 4-inch diameter. ...
- Types of Piping. Piping used for French drains should be perforated to allow for unimpeded water flow. ...
- Pipe Placement and Additional Considerations. ...
- Pipe-Free French Drains. ...
How to make a basement French drain?
Steps Download Article
- Plot out and mark the path of the French drain. The drain should run about 1 foot (or 30 cm) away from the basement's exterior wall.
- Dig out the floor of your basement along the path of the drain. ...
- Grade the bottom of the trench. ...
- Place the French drain piping into the trench with the perforations facing down.
Is 57 gravel good for French drain?
Washed clean stone with an average size of 3/4 inch. This is used as drainage stone inside of French drains and in the back of retaining walls and for gravel driveways.
What kind of rock is best for a French drain?
gravelFor the best drainage, look for coarse washed rock (gravel) that is screened, with a stone size of 1/2 to 3/4 inch. Smaller rock with fine particles could clog the holes of the drain pipe. Pea stone works, but the smooth stones settle together and don't move as much water as coarse rock.
Do you put gravel under French drain?
The old way of installing French drains is to do it without the gravel and the fabric. Without the gravel and the fabric, however, the drain can clog up with sand and soil over time.
Can you make a French drain with just gravel?
2:104:21FRENCH DRAIN, Lots of GRAVEL - YouTubeYouTubeStart of suggested clipEnd of suggested clipAway. Okay time to clean up we're going to go ahead and cover all this up put some soil back on topMoreAway. Okay time to clean up we're going to go ahead and cover all this up put some soil back on top of that separator. And put it together. Remember the key to a French drain is lots of gravel.
What is the best gravel for a French drain?
Hard rocks such as granite or river gravel prove viable options for a French drain because they won't break down over time as much as other rock varieties, such as sandstone and limestone.
How much gravel do I need for a 100 foot French drain?
To calculate gravel needed for a 100′ french drain, multiply the length of the trench by the width and depth. If you plan to lay down 4 inches of gravel, multiply 100 feet x 4 inches = 400 cubic feet. Since each bag equals 1.5 cubic feet, divide 400 by 16 to determine the number of bags you will need about 26 bags.
How deep should French drain be?
About 8 inches to 2 feet deepFrench 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.
Can you use pea gravel in a French drain?
Do NOT Use Pea Gravel, Pea Pebble, Pea Stone When Building a French Drain. When building a French drain, you want to use a coarse rock that has been screened and washed. The rock that you see in this French Drain is 3/4″ and larger. You end up with large voids that'll move far more water.
Should I use landscape fabric in French drain?
Non-woven geotextile fabric is the best choice for drainage applications where water flow through (permeability) is the main concern. Non-woven landscape fabric is commonly used in French-drains, drain-fields, and erosion control.
What drains better sand or gravel?
Sand compacts and retains moisture, therefore it does not drain as well as gravel. Although sand is not the best choice for back-filling a French drain, it does work well for some other types of drainage systems.
Why do French drains fail?
Over time, a French drain may become clogged. Tiny soil and clay granules slip through the pores of the landscape fabric and gradually build up inside the pipe. Another common cause of French drain clogs is root intrusion from grass, shrubs, and trees.
Is sand or gravel better for drainage?
It's recommended to place down a few layers of crushed rock or sand underneath the gravel in order to stabilize the drainage surface. When it comes to drainage material layer size, typically a two- to three-inch layer of gravel will effectively deter water buildup.
Can I use pea gravel in a French drain?
Do NOT Use Pea Gravel, Pea Pebble, Pea Stone When Building a French Drain. When building a French drain, you want to use a coarse rock that has been screened and washed. The rock that you see in this French Drain is 3/4″ and larger. You end up with large voids that'll move far more water.
Is river rock good for drainage?
River rock driveways work well because unlike asphalt or concrete, they will not split or dent overtime. They also provide superior drainage, allowing water to soak into the ground, instead of running off. Also unlike an asphalt or concrete driveway, you can install river rock gravel yourself.
How deep should French drain be?
About 8 inches to 2 feet deepFrench 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 the best drain line for a French drain?
Pea gravel is a good choice for french drain lines since it is a good size and affordable on any budget.
What is a French drain?
The bottom of the trench needs to have enough room to let water flow – without being packed in too tight! Remember, a french drain system is basically an underground river that lets you drain water into an area of your choosing – as long as you can slope the drain downhill.
What to do if your French drains clog every spring?
If your french drains clog every Spring you likely need to loose the bottom layer of gravel in your drainage system or double check the perforated pipe.
Why is my gravel drain line clogged?
If your fill rocks and pebbles are too big water will drain too quickly from the line and there won’t be enough surface area for the top layer of sand to sit on top. If the gravel you choose is too small then it may compact in the drain lines and cause a clog.
How do French drains work?
French Drains are powered by gravity and work by using a slight 1 or 2 degree downslope. The layers of filler rock and sand help prevent blockages and protect the piping. We recommend putting a layer of sod and larger pieces of rock around the entrance and exit for extra protection.
How long does river rock last?
We like to use river pebbles for this layer since it has already been exposed to running water and is difficult to erode – meaning it will last for at least 20 years. Be careful if it feels like the stone you are putting into the bottom layer feels like it can crumble in your hands – it will likely break up in the drain line. River rock on the other hand will be smooth to the touch and unbreakable!
What is the best filler for a French drain?
Coarse sand provides the filler for the top several inches of a French drain, whether you use a perforated pipe in the drain or not. Coarse sand doesn't clump or clog, and has been washed to remove impurities. Sod can be used on top of the sand, after placing a weed barrier cloth over the sand layer, or add decorative large rocks if you enjoy the look of stone and don't want to hide the drain completely. Using rock on top also guarantees you can find the drain next week or several years down the road to check how well it is working.
What is a French drain?
A French drain offers a gravity-assisted means of keeping the yard free from excess moisture. While several sizes and types of gravel may be used for the drain, your best option may depend upon the slope of the yard and whether you use a perforated pipe to help whisk the water away.
How do French drains work?
A French drain draws water away from one area, such as the ground near a house foundation, to prevent water from causing damage to the structure. To do this requires a sloped ditch or trench with the high point at the area requiring drainage; the slope from end to end is generally 1 to 2 percent. A layer of gravel fills the bottom of the trench, with several inches of coarse sand on top of that. Some French drains have sod over the sand to make them less visible, and some include a drain pipe in the bottom to ensure the drain structure lasts.
How deep should a French drain be?
In most installations, an 8-12″ wide trench will suffice. Enter the depth of the French drain. The standard depth is about 12″.
How much slope should a French drain have?
Drainage pipes installed in French drains should have at least an 1/8″ per foot slope. For more on calculating drain pipe slopes, click here.
How deep should a drain pipe be?
The standard depth is about 12″. On average this will allow for about 5″ above a 4″ drain pipe, and 3″ of top soil/grass above that. The depth may need to be increased if there are any humps or variability in slope of the area being trenched.
What is a French drain?
A French drain can be a great way to solve water pooling and water intrusion problems in your backyard. If you carefully estimate the gravel you will need using the French drain gravel calculator above and follow the tips outlined you can ensure a successful project.
What is the diameter of a 4" drainage pipe?
Drainage pipe outside diameter A 4" perforated drainage pipe has an O.D. of 4.215". Enter "0" if a pipe will not be used.
Can you use a catch basin in swampy areas?
You can use a catch basin like this one in real swampy areas to capture surface water at the beginning of the drain. I’ve used these with good success
How big should gravel be for French drains?
In french drains where there is not a pipe being installed, make sure to get even bigger gravel pieces. Try to get stones 1 and 1/2″ or bigger if possible. Additionally, it is wise to choose a harder rock for your base gravel so that it doesn’t wear down too quickly. Softer rocks that break down over time will become too small to properly drain ...
What is the purpose of gravel in a French drain?
In the set up of a french drain, gravel normally fills at least the bottom one third of the trench and a perforated pipe is laid on top of the gravel to allow even faster drainage in case the water is soaking into the ground faster than can be drained by the gravel. In french drains where there is not a pipe being installed, ...
Why is the French drain filled with gravel?
The gravel is one of the most crucial components to the french drain as it allows water that has soaked through the ground to be carried away down the slope of the french drain.
What stone is best for filling a French drain?
Vigoro All Purpose Decorative Stone – This stone is not quite as wide as the beach pebble but is still a great option for filling your french drain as it is extremely hard and will not wear quickly. The rigid nature of this stone will also be perfect for filtering soil out of the water which will prevent the drain from getting clogged.
What is a French drain?
A french drain is a type of draining system that allows pooling water to escape to a lower point in the yard or the street. The main concept behind the design is a slightly sloped trench ...
What is the best stone for french drain?
Mexican Beach Pebble – This is product is an ideal choice for french drain gravel. The stones are roughly 1″ to 1 and 1/2″ wide and are already smooth which is ideal for water to run along the surface of the stone. Vigoro All Purpose Decorative Stone – This stone is not quite as wide as the beach pebble but is still a great option ...
How effective is a French drain?
A French Drain can be an extremely effective method for solving a drainage problem in your yard and maintaining the integrity of below grade concrete walls. If you determine that a french drain is right for you, make sure to do your homework in terms of best practices for installation. Additionally, make sure to locate any utility lines ...
What kind of rock should I use for a French drain?
I prefer a ½” – 3/4” coarse washed rock that is screened. Pea stone I have found works but doesn’t move the volume of water. The more rock and larger the trench the more water the French drain can handle and the longer it will work.
How to make a French drain with filter fabric?
For best results you need to use these steps. Dig a 14” wide trench and line the trench with the 8 oz. commercial filter fabric. Then put 3 inches of rock at the bottom of the trench. Place the 4” perforated corrugated pipe (without a sock on the pipe) on top of the rock. Next fill in around the pipe with stone on all sides and wrap the filter fabric on top. Now it is fully contained to not allow sediment or solids to contaminate the French drain compromising its performance.
Do you need an inlet basin for air?
I have the question “Do you need an inlet basin for air” asked on appointments. Absolutely not ! If the French drain is built correctly, it will breathe just fine. If it needs an air inlet installed you have a bigger problem. All this does is allow contamination into the system. Where ever you have additional water problems on you property, just have a branch or finger ran off the main French drain. T or Y it into the French drain system building the addition the same as the main. Do not put catch basins in line on the French drain pipe because it will allow sediments and solids to impede the movement of the water in the French drain. Never tie the downspouts directly into the French drain pipe. This will fill it with shingle gravel and roof debris. I can’t emphasize enough the more rock, the better the French drain.
Measurements of the Area
Measure the area where you plan to set up a French drain system. This way, you can determine how many pipes you need to prepare as well as the amount of gravel, sand, and rock that you will use.
Amount of Water on the Area
Ground water generally comes from rain, so you have to know the average rainfall in your area to determine whether or not the French drain system should be wider and deeper.
Pipe Size
According to foundation repair experts, a typical French drain system in a residential home has a four-inch diameter. But if the area experiences a high volume of water, it might be suitable to install six or eight-inch pipes.
Types of Piping
Make sure that the piping used for French drains are perforated as this would enable an unimpeded flow of water. PVC is one of the most popular materials used for French drain piping because it’s widely available and relatively inexpensive.