How to Build a Soakaway for Improved Garden Drainage
Introduction
A soakaway drainage collects and redistributes rainwater in the ground. Building a soakaway includes testing the soil condition, excavating the area, digging it, laying geotextile fabric, placing plastic crates, wrapping them with membrane, connecting the pipe, backfilling the pit and replacing the soil.
A soakaway is an effective solution to manage surface water runoff, keeping your property safe from drainage hazards. In this blog, we will explore how to build a soakaway to improve your garden drainage and which things to avoid during installation.
What is a Soakaway and How Does it Work?
A soakaway is an underground pit that collects rainwater and surface runoff from roofs, gardens and patios and releases it back to the surrounding soil slowly. It is not connected to the foul sewer and manages only clear rainwater. Its working process follows a simple sequence:
- Rainwater falls from roofs, driveways and patios
- Water runs into gullies or downpipes
- Pipes carry the water into an inlet
- Water passes through a silt trap for filtration
- Water enters the soakaway chambers
- Water seeps through the soakaway walls
- Surrounding soil absorbs the water
How Do You Test Whether a Soakaway Will Work on Your Land
Knowing the condition or nature of the soil is essential before building a soakaway. A sandy soil can absorb water more quickly compared to clay soil. A percolation test is used to identify whether the soil is suitable for building a soakaway. This test is usually performed in four steps.
- Dig a small test hole in the area to a proposed depth
- Fill the hole with water and let it dry
- Measure how quickly the water level falls
- Repeat the test at least three times, changing the area
What Do You Need to Build a Soakaway
Once you understand the suitability of your soil, gather all the essentials required to build a soakaway. Having these essentials beforehand makes the process easier while reducing the selection time of specific items.
- Silt trap
- Shingle
- Soakaway crates
- Geotextile membrane
- Drainage pipes
- Shovel or mini digger
- Waterproof tape
How to Build a Garden Soakaway: Step-by-Step
After knowing the soil suitability and collecting the essentials, start building a soakaway. Choose the right location, which is away from tall trees whose roots can damage the soakaway and make sure the underground is clear of any gas, water and electrical systems. The key steps involved in building a soakaway are:
Step1: Excavate the Pit
Dig a hole in the selected area with a mini digger according to the required volume. For clay soil, keep the hole wider. Clear stones or debris from the base and prevent the walls from smearing.
Step 2: Lay the Geotextile Fabric
Lay a geotextile membrane inside the pit before installing crates. This membrane stops the soil particles from migrating to the crates and blocking the drainage system.
Step 3: Install the Soakaway Crates
Place plastic crates inside the lined pit. Tie adjacent crates to avoid movement and connect them correctly according to the manufacturer’s instructions.
Step 4: Wrap the Membrane
Make sure you add an extra layer of geotextile membrane while lining the pit, and now is the time to wrap it over the crates for water storage.
Step 5: Connect the Inlet Pipe
Connect a perforated drainage pipe from the downpipe and gutter drainage to the soakaway. Use a non-return valve for this inlet to stop the water backing up to the surface.
Step 6: Backfill and Reinstate
After lowering crates and installing pipes and inlet, backfill the area surrounding and over the crate, typically with sand or gravel, to complete the process.
Common Problems Faced During Soakaway Installation
Soakaways play a crucial role in maintaining water disposal. Small installation mistakes can make your soakaway ineffective, leading to a range of problems. Some of the common problems you face with your soakaway include:
Poor installation
A soakaway must be installed in the right location and the right size to store the water. A less deep soakaway in clay-rich soil will not be able to disperse the stored water properly.
Clogged Soakaway
Debris, tree leaves and soil particles can block the soakaway, preventing it from storing and spreading the water into the surrounding soil.
Soakaway Overflow
Extra water is stored in a small soakaway due to heavy rainfall and moves back up to the surface instead of absorbing into the soil.
Foul Odours
Strange odour emerging from the soakaway is an indication that your soakaway is facing problems like organic matter buildup or blockage.
Cracked Structure
Poorly designed soakaways can lead to damage or a cracked structure due to heavy vehicles and underground movements.
Soakaways are built for the long term with low maintenance. However, they require periodic checks and maintenance because leaving them unattended can lead to problems with waterlogging. Some maintenance tips for a garden soakaway include:
- Remove debris and clear gutters regularly
- Keep heavy weights away from the soakaway
- Monitor and check its structural integrity
- Arrange professional inspections if performance is poor
Conclusion
A soakaway collects rainwater and disperses it in the underground soil. It is a most effective way to dispose of rainwater, especially in weather-challenging, flooding or heavy rainfall areas. A percolation test is performed to check the soil suitability before building a soakaway.
A soakaway is built by excavating the area, laying a geotextile membrane, lowering crates, connecting pipes and backfilling the area to complete the installation process. If you are still confused, then you can contact Fast Drains for professional help, which is a team of specialists who can build your soakaway along with pre-installation tests. “If you are still unsure about your soakaway requirements, contact Fast Drains for professional advice and installation.”