Rainfall is something that everyone cherishes. As a gardener, it could mean a new lease on life for your plants.
However, things can go quickly go south if you aren’t prepared. Your patio is one such vulnerable spot.
A flooded patio is a prerequisite for slip hazards and mold growth. Additionally, you run the risk of damaging your foundation if the water seeps deep enough.
Fortunately, you can rainproof your patio, so it never floods again during inclement weather. Let’s dive straight in.
Table of Contents
- 1 Causes of Flooding In Your Patio During Rainfall
- 2 Tips To Keep Your Patio From Flooding
- 2.1 1. Improve Soil Drainage
- 2.2 2. Add Gravel
- 2.3 3. Install French Drains
- 2.4 How To Install A French Drain?
- 2.5 4. Install A Robust Drain System
- 2.6 Steps To Installing A Surface Drain In Your Patio
- 2.7 5. Employ Rain Barrels And Rain Chains
- 2.8 6. Maintain Your Existing Patio Drains To Avoid Clogging
- 2.9 7. Build A Soakaway
- 2.10 8. Install A Permeable Surface
- 2.11 9. Regrade Your Patio / Pour New Concrete
- 2.12 10. Build A Rain Garden
- 3 The Bottom Line
Causes of Flooding In Your Patio During Rainfall
If your patio is constantly flooding during rain, here are common reasons why that could be happening.
1. Roof Water
If your roof lacks gutters that channel water to a tank or reservoir, you will have lots of water flowing from the roof to your patio, causing it to flood.
2. Clogged Drainage System
Even with minimal rainfall, a patio with a clogged drainage system will start flooding with water within a short period. Leaves and debris are the common culprits.
3. Wrong Surface Pitch
A flat surface patio doesn’t simply cut it— giving you loads of headaches and stagnant water to care about. That is why you want to ensure that you set up your patio with a slight slope to allow surface water to run off.
Tips To Keep Your Patio From Flooding
Here are some easy workarounds that will help restore normalcy by keeping excess rainwater off your patio.
1. Improve Soil Drainage
This technique is handy if you live in an area with water retaining clay soil. Clay interferes with water flow, leading to flooding. An idea you can explore here is the use of Popup Drains.
Connect the drains with the underground downspouts. Technically, this is meant to create a PVC pipe system that pools water from the downspouts, ultimately dispersing it to a far larger sloped area (the drain pops up when filled with water).
The slope then takes the water away from your patio and foundation.
2. Add Gravel
A common cause of flooding in your patio is poor drainage from a non-porous/solid patio surface. This allows water to sit still on your patio for hours.
If this is a cause you’re grappling with currently, consider improvising the current design of your patio by adding gravel. Stones or ballast can also work fine in place of gravel.
For instance, you can incorporate gravel strips between your pavers that allow water to drain naturally.
3. Install French Drains
Another trick you can use to handle the drainage menace in your patio is building a french drain. For starters, a french drain is more or less like a ditch in the ground with a perforated pipe under a layer of gravel.
The PVC pipe helps you channel the water away from your patio and foundation to a more appropriate place.
French drains have a similar concept to gutters. The difference between the two is gutters collect rainwater from the roof while French drains manage water at the ground level.
The PVC pipes used typically have large holes every few inches. When water runs through the gravel, it accumulates in the PVC pipe via these holes.
The pipe then carries water away from your patio due to its slopping design.
Installation Materials And Tools you’ll Need
- PVC pipes/ Flexible Pipes
- Landscaping fabric
- Landscaping pins
- A Spade
- Level string
How To Install A French Drain?
Step 1: Dig A Trench
- During digging, ensure the trench slopes towards the direction you want the water to flow. Ideally, there should be a slope of 1-inch for every length of eight feet.
- You can use a level string between stakes to help you determine the correct angle.
- The effectiveness of the drain correlates with its size; thus, you should ensure your trench is at least 12 inches wide with a depth of 18 – 24 inches.
- There will always be a considerable amount of dirt after digging the drench. You should identify a place firsthand for dumping the dirt.
Step 2: Fill And Pipe The French Drain
- With the trench ready, you now want to fill it with crushed stone. This should only be at a few inches. We recommend covering the stones with a landscaping or geotextile fabric that is water permeable to prevent the growth of weeds.
- That done, now lay the pipes into the trench. You can use PVC pipes with predrilled holes or flexible drain pipes with slits. One big advantage of PVC is its durability and ease of cleaning with a plumber’s snake or pressure whenever there is a clog.
- If using a PVC pipe, you should ensure to fix an easy clean-out access point at the start. You can attach a 45-degree angle joint for this purpose.
- Remember to align the PVC pipes so that the drilled side faces downwards.
Step 3: Add Gravel And Finish Up
- Fill the trench with gravel and wrap landscaping fabric, holding it together with landscaping pins.
- Cover the trench with grass or sod.
It’s vital that you have a catchment barrel at the french drain terminus to ensure you are harvesting rainwater for future use in the garden.
4. Install A Robust Drain System
A surface drainage system with a pop-up emitter does the trick of channeling water away from your patio.
The pop-up emitter releases water when the drain system is full while remaining closed. This is vital to prevent rodents and dirt from entering the system. If you install this yourself, you’ll need about 10-12 hrs to do the job.
Before starting the project, check your Municipality for regulations on storm run-offs to ensure you’re operating within the confines of the law. Also, beware of the cost implications when installing the drainage system.
Materials and Tools you will Need
- Measuring Tape
- Concrete saw
- Plastic Guttering
- PVC glue
- Trenching machine (optional)
- Clear waterproof silicone
- PVC pipes 3” or 4”
- PVC Elbows
- PVC Pop-Up Emitter
Steps To Installing A Surface Drain In Your Patio
Step 1: Install A Linear Drainage Channel
The initial step involves molding plastic guttering in freshly-laid concrete. The advantages include lower costs and the relative ease of installation compared to traditional underground drainage systems.
Identify a suitable location where most of the water pools on your patio while installing the drain channel. Also, maintain a fall of 1 in 80 to provide an adequate slope for the water to run.
Step 2: Dig The Trench
- Next, you’ll need to dig a trench for the drain pipe. The trench should begin from a downspout or the surface drain mentioned in the first step to a point where you want the water to end up.
- Lay out the system by dry fitting it from the start point to the pop-up emitter.
- Use the measuring tape to measure and cut all the pipes needed. Glue the cut parts together at the end of the process.
- Test the system for water tightness by channeling water through a hose.
- Precautions: Maintain a downward slope while installing the pipes. Also, ensure the trench is broad and deep enough to house the pipe and the emitter.
Step 3: Install The Emitter
- Identify a low spot in your patio to install the emitter.
- Fix a PVC elbow at the terminus of the pipe and glue it.
- Make sure that the elbow is facing the sky.
- Slide the pop-up emitter into the elbow.
- Make sure the emitter is flush with the surface.
Step 4: Replant Your Sod/Grass
It’s all done and dusted. The next thing to do is backfill your sod back to its original location, ensuring to water it regularly until it fully settles in. Always remove the grass carefully to make it easily fit in when replanting.
We advise seeking the services of a local utility company for any ground installation project. They will help you mark the location of all ground utilities before you begin the digging.
Use a tarp for holding all the excavated dirt so that you can use it for backfilling after the exercise. Some gardeners use the trenching machine to make their work easier.
5. Employ Rain Barrels And Rain Chains
Why not use rain barrels and chains to stop your patio from flooding during rains?
What Are Rain Chains?
Rain chains are an alternative to traditional downspout systems consisting of metallic cups and chains linked together to assist water flow.
The whole purpose of having them is to harvest rainwater into rain barrels. They are functional enough to prevent your patio from flooding while adding beauty.
Rain chains are less prone to clogging by leaves and debris.
6. Maintain Your Existing Patio Drains To Avoid Clogging
As earlier highlighted, a prevalent cause of a flooding patio during rainfall is a clogged drainage system. Just like gutters, your patio drain is also prone to clogging and thus requires regular maintenance.
A straightforward way to prevent this from happening is to remove the debris or gunk manually. Wear gloves and get to work.
After removing the gunk, use a garden hose to push through any remnants to clear them out.
If this doesn’t sound like a solution, how about purchasing a blow bag. You’ll need to fit or screw it at the end of the hose and push it into the patio drain as far as you can.
When water flowing through the pipe reaches the perforated blow bag, it exits with force, removing the gunk, mud, or debris responsible for the clog.
Some gardeners also find snake-style drain cleaners handy in doing the job.
7. Build A Soakaway
A soakaway in your patio is handy to soak extra water into the ground. All you need to it is dig a vast hole and fill it with gravel.
They are more or less like a french drain but lack a pipe. You can couple soakaways with french drains for the best possible results.
An excellent place to locate them is at your patio’s bottom slope to allow excess water efficiently run down into it. The water will easily permeate through the gravel and gets to drain your garden soil.
Beware that soakaways don’t function well in areas with clay soil.
8. Install A Permeable Surface
Another solution to prevent your patio from flooding is using a permeable patio surface. You could explore options such as,
- Resin surface
- Eco-optiloc pavers
- Holland stone
Choose a material that best suits your surroundings and context. For instance, a resin patio surface allows water to drain through its surface without adding any additional materials such as gravel.
Resin is not only strong but durable and long-lasting. You also have various color options to choose from.
9. Regrade Your Patio / Pour New Concrete
Ever thought your patio could be flooding due to poor slope? If this is the case, water is not flowing freely away from your house but is instead pooling around your foundation.
That’s a recipe for disaster you want to fix in the shortest time.
Check to see whether other drainage options are feasible. For instance, you can remove paver rows near the house, add gravel underneath, and install new pavers to correct the pitch.
If this is not workable, you may need to pour new concrete to correct the poor slope. Gardeners with a solid slab patio could go for mud jacking. This comes at a cost, though.
You’ll need to enlist the services of a mud jacking company to drill holes in the patio close to the house and add mud, usually mixed with cement. Pumping mud helps add slope to the patio, causing water to flow away.
10. Build A Rain Garden
Rain gardens prove very effective in controlling water runoff and soil erosion from your garden or patio, all while adding beauty to it.
Read our comprehensive white paper on rain gardens and water harvesting to know more.
The Bottom Line
A flooded patio is not only a dangerous place for you and your children but is a breeding ground for harmful insects and pests.
We hope the above solutions will help keep your patio flood-free. Most of them are easy and won’t cost a fortune to implement.
That said, don’t rule out the option of hiring a professional in case you have any doubts. No more wet feet again.
Job Kiniale is a certified crop scientist and gardening enthusiast with a passion to help beginning gardeners navigate their newfound hobby. Let’s talk about plants, backyard ideas, and general gardening advice. Outside work, Job loves spending time with family.