Are you here here because you’re scratching your head and wondering how to unblock drains outside?:
- Is water pooling around an outdoor grate after it rains?
- Are bad smells drifting up from a gully trap?
- Has a drain simply stopped taking water at all?
Oh dear – they’re simply the every day, run-of-the-mill, usual signs that something is blocked outside, rather than inside your house.
But there’s good news. What’s that?
It’s understanding that how to unblock drains outside is probably something you can tackle yourself before it turns into a call-out – provided the blockage isn’t sitting deep in the sewer line.
Are you dealing with how to unblock drains outside the home for the first time? Or have you been through this before?
Either way, here’s how to work through it properly – step by step.
8 Simple steps for clearing an outdoor drain
If you work through these in order, and stop as soon as the water starts draining freely again, you’ll be back on track at your place.
1. Identify the actual blockage
Before doing anything else, work out exactly which drain is affected and how bad it is.
A stormwater grate overflowing after rain is a very different problem to a gully trap near the laundry or bathroom backing up with wastewater.
If you’re trying to work out how to unblock a drain outside specifically near the house, checking which fixtures inside connect to it will tell you a lot about what’s likely blocking it – and whether it’s just that one drain or something affecting several at once.
2. Clear visible debris by hand
It may be a bit gross, but you can do this! Simply put on a pair of gloves and remove any obvious leaves, dirt, litter or built-up sludge sitting in and around the grate.
Just doing this alone clears a surprising number of outdoor blockages, since surface debris is often the whole problem rather than anything further down the pipe.
It’s definitely worth doing this thoroughly before moving on, since a partially cleared grate can make it harder to tell if later steps are actually working.
3. Flush it with a hose
Once the visible debris is gone, run a hose directly into the drain opening on a strong, steady flow.
What does this do? It pushes through minor buildup sitting just below the surface and gives you a quick read on whether the blockage is minor or more serious based on how the water responds.
4. Try a plunger on the trap
For a gully trap or floor waste that’s still slow after flushing, a plunger creates enough suction and pressure to dislodge a blockage sitting a little further down.
Just make sure there’s enough standing water to create a proper seal before you start.
5. Use a drain snake or auger
If the blockage still hasn’t shifted, a manual drain snake fed into the pipe can hook or break up whatever’s causing the problem:
- Feed it in slowly
- If you feel resistance, work it back and forth gently – don’t force it.
Be aware: forcing a stuck snake can damage the pipe or push the blockage in tighter.
6. Try a natural clearing method
For anyone out there specifically looking for how to unblock drains outside naturally rather than reaching for chemicals, we’re here for you too.
You’ll need a mix of baking soda, vinegar and boiling water – and it’s definitely worth a try:
- Pour the baking soda in first
- Follow up with vinegar
- Let it fizz for several minutes
- Flush with boiling water.
Ok, it won’t get rid of a serious blockage, but it’s a reasonable, chemical-free step for a mild one.
7. Check the grate & fittings
Once water’s flowing again, take a look at the grate, trap and surrounding fittings for cracks, gaps or damage that might have contributed to the blockage or could cause debris to collect there again quickly.
A slightly misaligned grate, for instance, can let in far more leaf litter than one that’s sitting properly.
8. Know when it’s a job for a plumber
Has none of those worked? Does the blockage keep returning?
You’re probably dealing with something more serious than surface debris.
It could be:
- Tree root intrusion
- A collapsed section of pipe
- A serious sewer blockage further down the plumbing line.
Learning how to unblock sewer drains outside on your own has real limits, since these usually need a CCTV camera to locate the exact issue and a high pressure hydro jetter to clear it properly without damaging the pipe.
Remember: Trying to force a stubborn sewer blockage with DIY tools alone can sometimes make the underlying problem worse rather than better.
Keeping outdoor drains clear going forward
Once you’ve sorted the immediate blockage, a bit of regular attention keeps it from becoming a repeat problem.
Clearing leaves and debris from grates every so often, especially after storms, goes a long way toward keeping water moving the way it should.
Are you often finding yourself asking how to unblock outside drains at home no matter how often you clear them? That’s usually a sign of an underlying issue – something like root intrusion or a low point in the pipe. And DIY methods can maybe manage them short term, but the underlying cause will still be sitting there, waiting for an actual fix.
Have you worked through our 8 steps and the drain’s still not draining properly? Do you simply want it looked at properly and dealt with straight away – for good?
Get in touch with the friendly team at Fluid Plumbing.
We can diagnose exactly what’s going on with a proper inspection and clear it the right way – whether it’s a simple surface blockage or something further down the line, so you’re not repeating these steps every few months.
Give us a shout at Fluid Plumbing today.
