What Is a Soakaway and How to Build & Install One?

Soakaway Drainage

If you’re looking for a sustainable solution to manage rainwater and reduce the risk of flooding, you might be wondering: what is a soakaway? In simple terms, a soakaway is an underground drainage system designed to disperse excess surface water into the ground naturally. In this guide, we’ll explain what a soakaway is, walk you through step-by-step instructions on how to build a soakaway and how to install a soakaway and discuss the differences between a homemade solution and a professional installation.

Understanding Soakaways and Their Benefits

A soakaway works by collecting rainwater from gutters, driveways, or other impervious surfaces and gradually allowing it to infiltrate into the surrounding soil. This method not only prevents water from pooling on your property but also reduces pressure on municipal drainage systems and helps recharge groundwater.

There are many benefits to installing a soakaway. For example, by effectively controlling water runoff, a soakaway helps prevent flooding and waterlogging. It also supports an eco-friendly, natural water cycle by allowing rainwater to seep back into the earth, reducing the burden on public sewers and potentially lowering your drainage charges. Moreover, once properly installed, a soakaway requires minimal maintenance—although periodic checks for debris or silt are wise.

Homemade Versus Professional Soakaways: Which Is Right for You?

While the basic principle behind every soakaway remains the same, the method of construction can vary significantly. Many homeowners consider a DIY approach, especially when the idea of a homemade soakaway seems cost-effective. However, the differences between a homemade system and a professionally installed one can have a lasting impact on performance and reliability.

Homemade Soakaway

A DIY soakaway might work well if you understand your property’s drainage needs and carefully follow guidance on how to build a soakaway. Typically, a homemade solution relies on general rules of thumb and may not fully account for the unique conditions of your site—such as precise soil permeability or optimal sizing.

Without professional testing like a percolation test, you risk issues like silting, inefficient water dispersal, or even potential damage to your home’s foundation.

professional Soakaway

On the other hand, professional soakaway installations start with a thorough site assessment that includes soil testing and detailed calculations. Experts design the system to perfectly match your catchment area and ensure that every aspect—from the placement of drainage pipes to the wrapping of soakaway crates in geotextile membrane—is engineered to meet local building regulations.

This meticulous approach results in a robust, long-lasting system that can handle even extreme weather conditions.

In short, while both approaches aim to solve the same problem, a professionally installed soakaway offers peace of mind through superior design, material quality, and installation precision. If you’re planning a new extension or already experiencing drainage issues, investing in professional help is likely to save you time, money, and future headaches.

How to Build a Soakaway

Whether you decide to tackle the project yourself or call in a professional, it’s helpful to understand the basic steps involved in building a soakaway. The DIY process is manageable with careful planning and the right materials:

Step-by-Step Instructions:

1. Plan and Assess:

Start by choosing a location with permeable, ideally sandy or loamy soil, and ensure it’s at least 5 meters away from building foundations. If you’re unsure about the soil’s drainage capacity, conduct a percolation test.

2. Excavate the Pit:

Mark out and excavate a pit slightly larger than the dimensions of your soakaway crate system. For example, if you’re using a modular system that measures roughly 1m x 1m x 1m, allow extra space around the sides for backfill.

3. Prepare the Base:

Lay a 150mm layer of sharp sand or pea gravel in the bottom of the pit to create a stable, permeable base for the crates.

4. Assemble and Place the Crates:

Assemble your soakaway crates according to the manufacturer’s instructions. Use cable ties or clips to temporarily secure them, then wrap the outer surfaces with a non-woven geotextile membrane. This prevents soil from clogging the voids in the crates and maintains efficient water flow. Carefully lower the wrapped crates into the pit, ensuring they are level and correctly aligned.

5. Connect the Drainage:

Install the drainage pipe so that rainwater from your gutters flows directly into the soakaway. Secure the connection by wrapping the geotextile membrane around the joint to prevent soil ingress.

6. Backfill the Pit:

Add a 150mm layer of pea gravel or sand around and on top of the crates. For garden applications, a total cover of around 300-350mm is generally recommended. Lightly tamp the material to ensure stability while keeping enough void space for water infiltration.

7. Finish the Surface:

Replace any removed turf or topsoil, compacting it to complete your garden’s look. Over the next few days, monitor the area for any depressions due to settlement and add additional topsoil if needed.

How to Install a Soakaway

When using pre-manufactured soakaway crates, the installation process is similar to building a system yourself. The key is ensuring quality workmanship at every stage:

Location and Connections:
Position your soakaway in a low-lying, unobstructed area away from buildings and pollution sources. Make sure the drainage pipes are securely connected, as poor connections can lead to leaks or blockages.
Quality Backfill:
Use clean, angular aggregates such as pea gravel. These allow for open void spaces, which are essential for effective infiltration. Avoid materials that may contain fine particles, as these can clog the system over time.
Geotextile Wrapping:
Whether you’re installing the system yourself or hiring a professional, a tightly wrapped geotextile membrane is crucial. It acts as a barrier against soil ingress while still permitting water flow, ensuring long-term performance.

By carefully following these guidelines, you can achieve an effective soakaway installation that protects your property and promotes sustainable drainage.

Maintenance and Long-Term Considerations

A well-designed soakaway is inherently low maintenance, but regular inspections are key to ensuring long-term efficiency:

Periodic Visual Checks: Every few months, inspect the system for signs of silt build-up or debris that might obstruct water flow.
Silt Trap Upkeep: If your setup includes a silt trap, clean it periodically to maintain unobstructed water movement.
Surface Monitoring: Keep an eye on the surrounding area to ensure vegetation or other obstructions do not interfere with water entering the soakaway.
Professional Inspections: Consider a professional drainage survey every few years, particularly after heavy rainfall events, to verify the system’s performance.

Final Thoughts

Understanding what is a soakaway and learning how to build a soakaway or install a soakaway can transform your approach to water management on your property. These systems effectively prevent waterlogging, recharge groundwater, and reduce the burden on public sewer systems. While a DIY approach might seem attractive initially, the benefits of a professionally installed soakaway—such as precise design, adherence to local regulations, and high-quality materials—often outweigh the potential cost savings of a homemade solution.

By choosing a professional installation, you not only ensure that every detail is optimised for your specific site conditions but also protect your property from the risks of poor drainage. In the long run, professional expertise means fewer headaches, reduced maintenance, and a more robust solution that will serve your home for years to come.

Ready to Upgrade Your Drainage System?

If you’re ready to invest in an effective and long-lasting soakaway installation that safeguards your property from water damage, our team of experts is here to help. We offer professional advice, high-quality soakaway crates, and complete installation services tailored to your needs.