Does a French drain need planning permission?

Generally, a small French drain on your property that doesn't change the flow of runoff entering and exiting your yard won't need a permit. Major projects that warrant your French drain to discharge into a municipal sewer or roadside ditch, however, do require one.


Can I install my own French drain?

Because digging the trench can be difficult work on your own, get friends and family to help if possible. Once the trench is complete, installing a French drain is a straightforward process. The new drain will get runoff water under control, protect your basement and keep your yard from becoming a swamp.

How close to a house can you dig a French drain?

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.


What is the minimum depth for a 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.

What is the maximum slope for a French drain?

A French drain needs a slope to work properly. The slope should descend at a rate of 1%. That rate is equivalent to a 1-foot drop for every 100 feet of French drain. Alternatively, your property may have a natural slope that steeper, and that's fine.


What Planning Permission Do I Need? | Property Advice (UK)



What goes at the end of a French drain?

Your French drain should end where it is most appropriate to deposit excess sprinkler system water and rain water it carries. Most often, French drainage systems are installed to carry water towards the front of a house near the sidewalk or out into the road if you are able to cut through the curb.

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.

Do you need to put gravel under French drain?

The most reliable way to eliminate undesirable, free-standing water is to install French drains with slotted pipes, filter fabric and gravel. The old way of installing French drains is to do it without the gravel and the fabric.


How much does it cost to install a French drain?

A French drain can be a lifesaver for a home with water issues, but it doesn't come cheap: the average French drain cost is often between $500 and $18,000. Most homeowners pay somewhere around $5,000 to have a professional install a French drain in their yard.

Can a French drain just be gravel?

Officially a French drain is a gravel drain with no pipe. The water just collects in and travels through in a gravel or stone filled channel that starts from the surface or just below it. But in modern times, and for practical purposes, we will consider a French drain to include a drainage pipe in the gravel.

Does a French drain increase home value?

The value of the property. 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.


Are French drains a good idea?

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.

Does a French drain weaken foundation?

That's right, homeowners often install French drains to protect their foundation from hydrostatic pressure and water intrusion, but they can actually damage the concrete! Let me explain. French drains are covered with gravel to catch the water and let it drip into the perforated pipe below.

How much does it cost to install a French drain UK?

The average cost of installing a French drain lawn drainage system is around £30 – £40 per foot. The exact price you pay will depend on the size and length of the drains needed for your garden, as well as the individual tradespeople you hire to do the work.


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

The main difference between the two is that French drains capture and remove groundwater while trench drains quickly remove surface water before it can saturate the ground. Here's a closer look at each type of drain.

Do plumbers install French drains?

If installed properly by a qualified plumber, a French drain can last for a very long time. In some circumstances, shallow French drains can be easy to install as a DIY project.

What is the life expectancy of a French drain?

Generally speaking, a French drain will last approximately 30 to 40 years. However, the above-mentioned factors may shorten its life cycle and it must then be replaced by a team of foundation experts.


How hard is it to dig a French drain?

This can be a very involved task that means digging all the way down to the footings—a job for a pro. However, if the problem is surface water reaching the foundation from uphill, then a much easier French drain whose trench is only a couple of feet deep can be used to intercept and divert the water.

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 use PVC pipe for French drain?

While corrugated pipes have their place in some applications, PVC is the sound solution for a French pipe installation. At Align Foundation Repair, this is our go-to material for underground drainage systems.


Can French drain have grass on the top?

Yes, while our grass seed varieties promote a deep root system, you can still safely plant them over a French drain. In order for the grass seed to thrive, make sure to put topsoil over the gravel.

Will a French drain work in winter?

A French drain will work fine in a cold environment. The French drain must be placed below the frost line for it to work properly in these bitter cold environments. This is critical for the drain to work all year round, without obstructions such as freezing.

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.


Do French drains need to be cleaned?

Despite the design's best efforts, French drains get clogged by dirt, debris and silt. 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.