Does your yard turn into a total swamp every time it rains? Worse still, is water pooling around your foundations? A French drain might be exactly the fix you’re after.
It sounds like something out of a renovation show, slightly intimidating and vaguely European, but the reality is a lot more down to earth. It might even be something you could have a go at yourself.
In this guide, we’ll walk you through:
- What is a French drain
- Whether you can really can tackle it yourself
- A simple French drain installation process broken into easy-to-follow steps.
What is a French drain, really?
Despite the fancy name, a French drain is a wonderfully simple idea.
It’s a trench filled with gravel, containing a perforated pipe that collects water sitting underground or pooling on the surface, then carries it somewhere it won’t cause trouble.
Picture a French drain diagram in your head: A sloped channel running from the wet spot in your yard to a lower point where the water can safely exit, whether that’s a garden bed, a stormwater connection, or just further away from your home. Gravity does all the heavy lifting, which is exactly why getting the slope right matters more than almost anything else in the process.
Is this actually a DIY job?
If we’re talking about a shorter, straightforward version, genuinely the answer is yes. If you’re dealing with a soggy patch of lawn or water collecting along a fence line, and the total length is under about 15 metres, this is a project plenty of confident weekend DIYers take on themselves.
Where it gets trickier – and where we’d suggest calling in the professionals – is:
- Anywhere near your home’s foundation
- Anywhere involving underground utilities
- Anywhere the slope and soil conditions are genuinely tricky to read.
And before you dig anything at all, always get your underground services located – since hitting a gas or water line turns a weekend project into a very expensive mistake very quickly!
How to install a French drain: Step by step
So if you’ve weighed up whether it’s a DIY job or one for the pros, here’s the process itself, broken down into simple steps.
1. Find the problem and plan your route
Watch where water actually pools during a decent downpour rather than guessing, since it often surprises you.
Mark a path from that spot to a lower exit point using stakes and string, and never direct water onto a neighbour’s property.
2. Dig your trench
For a standard French trench drain, aim for roughly 45 to 60cm deep and 30cm wide.
The trench then needs a consistent downward slope of at least 1 percent, meaning around a 2.5cm drop for every 10 metres of length, so check it regularly with a spirit level as you go.
3. Line the trench with fabric
Lay a permeable landscaping fabric along the base and sides of the trench, leaving plenty of excess hanging over each edge. This stops all that silt and dirt (and roots) from clogging everything up down the track.
4. Add a base layer of gravel
Pour in around 5 to 7cm of gravel along the bottom, keeping the slope consistent as you go. This gives the pipe a stable, well-draining bed to sit on.
5. Lay your pipe
Place your French drain pipe on top of the gravel with the drainage holes facing downward, so water can seep in from the gravel bed below rather than just running along the top.
Connect any sections carefully and double check the slope hasn’t shifted.
6. Cover with more gravel
Fill in around and over the pipe with additional gravel, leaving roughly 10 to 12cm of space below ground level for topsoil or turf if you want it hidden.
7. Fold over the fabric and finish up
Wrap the excess fabric over the top of the gravel to keep dirt from working its way down, then backfill with soil and reinstate the lawn or garden bed on top.
And you’re done!
What about a pipeless option?
Not every situation needs a pipe. A pipeless French drain – sometimes just a gravel-filled trench without any pipe running through it – works pretty well for smaller drainage issues where the volume of water is modest, and the distance is short.
It’s simpler and cheaper to build, but it drains more slowly and handles less water than a properly piped version, so it’s worth matching the design to how much water you’re actually dealing with.
When to call in the pros
A well-built French drain system can genuinely solve years of drainage headaches – but a poorly sloped or badly planned one can leave you with worse pooling than you started with.
So, think carefully about whether your project:
- Is getting near the house
- Involves a longer run
- Or you’re just not confident reading your yard’s slope accurately.
If you’re not sure, that’s exactly when it’s worth bringing in a professional rather than risking a redo.
If you’d rather leave it to people who do this for a living, our team handles French drain installation Sunshine Coast wide – from small residential fixes to larger drainage projects. Give Sunshine Coast Plumbing and Hot Water a call and we’ll sort your yard out properly.
