A French drain is a type of drainage system that is used to deal with an excess of surface water. And, while in some instances you can reduce your French drain costs by installing one yourself, your final budget will depend on a number of different factors.
Named after Henry French, the 19th-century American farmer who developed and popularised them, they essentially consist a trench dug, at a gradient, into the ground, lined with membrane, filled with aggregate and often a perforated drainage pipe.
Suitable for gardens and driveways, we take a look at how much your French drain costs could amount to, and exactly what you will be paying for.
Average French drain costs
"A French drain is a simple but effective way to divert water away from problem areas. Costs can vary depending on length and ground conditions," confirms Aaaron Willcox from AW Plumbing and Heating, and a valued Checkatrade member, "but for a standard domestic setup you’re usually looking at £800–£1,500.
"The key is using the right gravel and ensuring the fall allows water to drain naturally," he adds.
What will also impact your French drain costs are whether you are able to do the work yourself or require a professional for installing a French drain.
"Costs will need to factor in the project complexity, the length and size of the French drain, the materials required and the labor costs for installation," he explains.
"Installing a small French drain for example, usually takes between 1 to 3 days, but a larger, more complicated job typically takes between 3 to 5 days."
Will Temperley, MD of Fortis Foundations, says labour costs will also depend on the contractor’s experience and where you live.
"In addition," he adds, "the cost of materials including gravel, landscape fabric, PVC or perforated pipe, is around £7 to £15 per metre.
“Combining labour and materials, you can expect to pay approximately £45 to £90 per metre.”
Aaron Willcox is an independent, fully qualified and fully insured plumbing and heating engineer operating in and around the Kent area , offering a wide range of services, competitive rates and 24/7 emergency call outs.
Will Temperley founded Fortis Foundations in 2020, bringing over 20 years of rail and construction industry experience to the business. Fortis Foundations provide civil engineering products and services, specialising in foundations and piling to the rail, civils, energy, residential and water sectors. The family-run business is renowned for delivering safe and sustainable solutions at the forefront of innovation and technology.
Managing French drain costs
If you are hoping to save on your French drain costs, then you'll also need to factor for a number of different items and products to keep a lid on how much you spend.
"DIY costs for a French drain include costs for materials (piping, gravel etc), rental equipment and potential permit fees," outlines Aaron Willcox.
"You'll need to factor in hiring a mini digger, which cost upwards of £75 a day," explains Will Temperley. “You also need to take into account additional tools to hire or purchase such as shovels, rakes, and compaction equipment which will all add to the overall expense of a project,” he adds.
Tools and kit for French drains
Transport your French drain gravel in this heavy duty garden wheelbarrow
Use this perforated pipe when installing a French drain
A 20mm gravel suitable for drainage purposes
What can increase French drain costs?
"The excavation can also be expensive if you're digging a deeper and/or wider trench for your French drain. Hard or rocky ground will also increase the cost, as it will be more difficult and take longer to excavate," explains Aaron Willcox, and this can impact on either the length of time you need to hire a digger for DIY purposes, or how long it takes the professionals to complete the job.
"Limited site accessibility can also cause a strain on time and money,” adds Will Temperley.
Pipe material and size are another factor – higher-quality or larger-diameter pipes are more expensive. Finally, longer drains require more materials and labour and post-installation landscaping or surface restoration, which can add to the total cost.
“French drains also require periodic maintenance to remain effective, which should be factored into the long-term cost," notes Will. "Regulatory compliance is also imperative to consider. Ensuring the installation complies with local building regulations might incur additional costs."
FAQs
Is a French drain cheaper than other drainage types?
There are alternatives you can look at if French drains don’t meet your property’s needs and budget. Soakaways can be cheaper or more expensive than French drains depending on the size and complexity. Building a soakaway typically involves less piping but may require more extensive excavation and materials like rubble or crate systems.
“However, French drains are often preferred for their effectiveness in managing surface water and are cost-effective in the long term, especially in areas prone to waterlogging,” notes Will Temperley.
For more details on the options, take a look at our article on drainage costs.
Are there other alternatives to French drains?
"Swales, permeable paving and rain gardens are all alternative options to French drains," says Aaron Willcox.
"Swales are shallow, wide channels that are dug into a natural slope in your garden. They collect and redirect surface water similar to how a French drain works. Rain gardens are built by planting specific vegetation to collect excess rainwater, filter it, and allow it to soak into the soil.
"Permeable paving is also a much more common option often used in urban areas," he adds. "It works by using paving materials that allows water to pass through it and seep into the ground, rather than pooling on the surface. Permeable materials like gravel, permeable asphalt and porous concrete are typically used."
Our expert's final advice before finalising your French drain costs?
"Before installing a French drain system, I always recommend speaking to a local drainage expert," says Aaron Willcox. "You may also want to check in with your local Building Regulations office for their advice," he adds.
"It is advisable you have a professional assessment of the property to determine the most efficient drainage solution, which may add to the initial cost," agrees Will Temperley, "but ensures effectiveness and compliance which can ultimately save you time and money in the long run.”
For more information on getting the drainage right in your home, check out our guide to driveway drainage and how to make sure your patio drainage is fit for purpose.
