Question: How Much Gravel Do I Need For A French Drain

How much gravel do I need per foot of 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. That’s 1200 x 6 x 18 = 129600 cubic inches. The difference between these will be the volume of gravel you need. Thats 129600 – 15080 = 114520 cubic inches.

Is gravel necessary for French drain?

Good drainage is important to ensure that a home stays dry and free of mold. 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.

How much gravel should be on top of a French drain?

French drain gravel should be washed three quarter inch minimum and as large as 1 ½ ” crushed stone. The upper 12 inches above the pipe shall be filled with native soil, to avoid having crushed stone over the perforated pipe that could damage the pipe.

How much gravel do I need for drainage pipe?

Cover the pipe with about 3 inches of gravel or crushed stone, but not enough to cross above ground level.

How much gravel do I need for a 50 foot French drain?

How much gravel do I need per foot of 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 deep should a 4 inch French drain be?

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.

Can you make a French drain with just gravel?

Installing the Drainage Pipe and Gravel To make your French drain last a long, long time you need to use these following items: Clean or washed gravel (not crushed limestone – it becomes cement like) Permeable landscape fabric (they kind water passes through).

What kind of gravel for a French drain?

The stone should be no less than ¾” and dense (we suggest Granite, or River Gravel) so it will allow good water flow. Lime Rock, although inexpensive, is a poor choice for a French Drain because it will begin to deteriorate over time and eventually begin to pack down and restrict flow.

What size rock is best for French drain?

Use Natural 1-1/2″ round rock for best drainage. Washed rock is ideal. Avoid small pea gravel as the spaces in between stone is smaller minimizing flow rates. Avoid Crushed Rock (minus) that compacts and has “fines” that will clog pipe inlets.

How do you calculate gravel for drainage?

Deduct the volume of the pipe from the volume of the trench. The result is the volume of gravel required to fill the drain. Gravel is sold in cubic feet or cubic yards, so round the value up to the nearest whole unit. One cubic yard of gravel is 27 cubic feet.

What size is #57 gravel?

Stones in AASHTO #57 blend are detected with a 1.5-inch sieve, which is why the #57 stone size is around 1 to 1.5 inches. Its size makes it useful for weight-bearing applications such as foundation beds and driveways.

How much area does a French drain cover?

Generally, a French drain should drop at least one percent in depth for every 100 feet of length.

How much is a French drain per foot?

According to Fixr, the average French drain costs $4,500. An exterior drain located fairly close to the surface could cost as little as $1,000, or $25 per linear foot on average. Drains installed under your basement floor could cost $2,000 or more. Expect to pay $60 to $70 per linear foot for installation.

Is pea gravel good for 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.

How shallow can a French drain be?

DIGGING A TRENCH FOR A FRENCH DRAIN Because there is a direct relationship between the diameter of a drain pipe and its relative effectiveness, make your trench no smaller than 12 inches wide, and aim for a depth between 18 and 24 inches.

Does French drain need an outlet?

A properly designed French drain system does not require an outlet. The water will simply soak into the soil as it flows along the perforated pipe. In fact, a French drain doesn’t require an inlet on just one end either.

Is 57 gravel good for French drain?

You can use #57 gravel for paths and small runoff drains. For larger and more complex drains, such as a french drain, we recommend #3 crushed stone.

Can you cover a French drain with grass?

The simplest drain is a classic French drain, which is nothing more than a trench filled with coarse stone or gravel. The drain can be left open or, if aesthetics are a concern, can be covered with a couple of inches of topsoil and sod.

Can I use river rock for 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 long should a French drain be?

The average French drain should be about eight inches to two feet deep. Systems built around foundations, retaining walls, and sub-ground living spaces may need to be deeper. Pipe length. This factor depends on specific elements of the project.