Can a French drain go uphill?

The pipe needs only a slight slope to move water effectively. If, however, your property is completely flat or a portion of your drain runs uphill, you'll need to pump the water or run your pipe across an adjacent sloping property.


Can a French drain flow uphill?

Michaels, Md. A: Yes, French drains do work — in combination with other measures. On a slope, where water is moving underground toward a house, an exterior French drain across the property, uphill of the house, can sometimes redirect the flow around the building enough to keep a crawl space or basement dry.

Does a French drain have to go downhill?

All of your drain pipe (with one exception) must slope slightly downhill. Usually 1/8" per foot is plenty for drainage, this is the same as the commonly recommended 1% slope. Note that I said the drain pipe must be sloped rather than the French drain.


How steep can a French drain be?

A French drain needs a slope of no less than 1%. That means the system should slope at least one inch for every eight feet of length from the highest point of the drain field all the way to the drain exit.

Can a drainage pipe go uphill?

As long as the hill a pipe goes up is LOWER than the 'top' of the pipe (and the outlet is lower still), then the pressure of the water 'up the pipe' will push the water up any (smaller) hills on the way from 'top' to 'bottom' (inlet to outlet). Is it possible for water to run uphill naturally? Yes.


How to Run Yard Water Uphill



Can you run a drain upwards?

No, you should not do that. As mentioned in a comment, the drain is going to fill up with gunk and clog. Depending on use, you'll find that you have to snake this line quite often.

Can French drains be level?

French drains need to have a slope of at least 1 percent, so the force of gravity will work for you. This means that the drain should slope down a total of at least one inch for every 10 feet of pipe.

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.


Can you walk over a French drain?

These walkways catch and reroute standing water, while providing a beautiful and clean place to walk. Popular in the space between houses, drainage walkways are basically a stepping stone path installed over the top of a French drain system. They function much like a dry creek bed, but allow for walking on top.

Can a French drain get full?

But, just like any other type of drain, French drains are susceptible to clogging. Soil and debris have a tendency to build up inside the pipes, eventually stopping water from flowing altogether. To avoid letting water back up into your home, follow this French drain cleaning guide.

What does a French drain empty into?

French drains provide an easy channel for water to flow through. Water runs into a gravel-filled trench, then into perforated pipe at the bottom of the trench. Water travels freely through the pipe, which empties a safe distance from the house.


How long will a French drain last?

When enough sand, clay or silt gets past the fabric, the gravel spaces fill and the effectiveness of the french drain ends. This is why most experts state that a French drain is not a long-term solution to a drainage problem: You have to dig it up and reinstall it every eight to 10 years.

How do you drain water from a hillside?

Dig a trench. Use a shallow, gravel-filled trench to catch and slow runoff, especially at the base of a slope or alongside a driveway or patio. For slopes, consider creating a dry creek to catch, slow down and direct runoff, perhaps to a rain garden (see below).

Can you make water flow uphill?

The starting point of all rivers is higher than their end point. However, under the right conditions, small amounts of water can be drawn upwards, against the tug of gravity, through a phenomenon known as "capillary action". For this to occur, however, the water must be confined into a small flow space.


How deep is the average French drain?

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.

How far should a French drain be from the house?

A general rule of thumb is that a french drain should be installed around three feet away from the foundation of a home, but this can vary depending on individual landscaping factors such as where the water is pooling and where gutters are already aligned.

Can you run a gutter into a French drain?

A French drain is actually a network of pipes laid in trenches dug beneath the ground through which water runoff can flow. This structure can be attached to your downspouts and will work seamlessly with your existing gutters.


How long do Exterior French drains last?

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.

Can you put dirt on top of a French drain?

Can I cover a French drain with dirt? Because a French drain has holes throughout the pipe which allow it collect water, you should not install dirt on top of the drain pipe. Installing dirt will clog the pipe and the holes, rendering it useless.

How often do French drains need to be cleaned?

French drains need annual maintenance

They do need to be cleaned out regularly – about once per year – to ensure that they continue to direct water away from the building's foundation. The best way to clean a French drain is mechanically, using an electric snake.


Do adding French drains increase home value?

Installing a French drain will increase the value of your home if you are planning to sell it in future. On the other hand, a substandard French drain may spell disaster for neighboring residences.

Do you cap the end of a French drain?

Cap the end at beginning of the system. Level rock 4 inches from the top of the trench. Note: If you just dump rock on top of the pipe, it will shift to one side of the trench. Make sure to keep it in the middle of the trench.

What is the difference between a French drain and a trench drain?

Aside from what we've listed here, the difference between a French drain and a trench drain is that a French drain is used for water that is underground while a trench drain diverts excess water from a surface.