Soakaways & Percolation Tests
Giving Water Somewhere to Go
A soakaway is a drainage solution designed to collect excess water and disperse it safely back into the ground. Instead of water flooding your driveway or sitting on your lawn, a soakaway gives it a controlled place to go. There are different types depending on what needs draining:
- Crate Soakaways: Plastic crates wrapped in a protective membrane (usually for rainwater).
- Concrete Rings: Large perforated concrete cylinders with a porous base for handling bigger volumes of surface water.
- Drainage Fields: A network of trenches with perforated pipes (used for treated wastewater from septic tanks).
In simple terms: A soakaway helps water soak into the ground naturally to prevent flooding and pooling.
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Why Soakaways Are Needed
You generally need a soakaway when water cannot drain away naturally or when you are adding new hard surfaces to your property. Customers typically call ASL for:
- Flooding: Puddles on lawns, driveways, or patios that won’t go away.
- New Builds: Extensions or conversions that need a new drainage point for guttering.
- Septic Systems: Replacing a failed “drainage field” for a septic tank or treatment plant.
- Overflowing Gutters: Where the existing soakaway is full or blocked.
- Compliance: Meeting Building Regulations or Sustainable Drainage (SuDS) standards.
The Percolation Test (“Perc Test”)
Before we install anything, we need to know if your ground can actually absorb the water. If you build a soakaway in heavy clay soil, it will simply fill up like a bathtub and flood.
A Percolation Test determines how quickly water drains through your soil. We carry this out strictly in line with Building Regulations (Document H).
The process involves:
- Excavating test pits in the proposed area.
- Filling them with water.
- Timing exactly how long it takes to drain away.
We provide a full report with the results. If the ground is suitable, we calculate the exact size of soakaway you need. If the ground is unsuitable (e.g., heavy clay), we will advise on alternatives, such as a borehole soakaway.
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How We Install Soakaways & Drainage Fields
We follow a structured, compliant process to ensure the system lasts for years.
1. Test & Design – We use the percolation test results to design a system that is the right size for your property and positioned the correct distance from buildings and boundaries.
2. Excavation – We use machinery to dig the pit or trenches. We are careful to store topsoil separately so we can reinstate your garden neatly afterwards.
3. Installation
- For Surface Water (Rain): We install modular crates wrapped in geotextile membrane or concrete rings. We often add silt traps or catchpits to stop debris clogging the system.
- For Foul Water (Septic): We lay perforated pipes in trenches surrounded by clean, granular stone to allow treated waste to filter into the soil safely.
4. Connection – We connect the new system to your existing drains, gutters, or septic tank outlet.
5. Testing & Handover – We backfill the area and compact the ground. We test the system to ensure it functions correctly and provide you with maintenance advice to keep it running smoothly.
Ground Conditions & Suitability
Soakaways only work if the ground allows it. When we assess your site, we look at:
- Soil Type: Is it sand, chalk (good drainage), or clay (poor drainage)?
- Water Table: Is the natural groundwater level too high?
- Space: Is there enough room to keep the soakaway 5 meters (or more) from the building?
Maintenance & Diagnostics
If you already have a soakaway but it isn’t working, we can help. We can:
- Use CCTV cameras to check the pipes feeding the soakaway.
- Check silt traps and catchpits for blockages.
- Use high-pressure jetting to clear debris.
- Replace old systems that have become saturated or blocked with roots.
Benefits to the Customer
- Flood Prevention: Stops standing water damaging your driveways and garden.
- Reliability: Gives rainwater and wastewater a managed route into the ground.
- Compliance: Ensures your property meets Building Regulations and environmental standards.
- Protection: Keeps water away from your home’s foundations.
- Sustainability: An environmentally responsible way to handle water runoff.
ASL ensures every system is designed based on real soil conditions and correct technical standards.
Testimonials
What Our Clients Say
“I called at 08:10 hours to report a blocked drain. A little while later, Darren rang to tell me he’d arrive in half an hour. He arrived on time and resolved the problem quickly and without fuss. He was polite and friendly throughout. Within two hours of reporting the blockage, all was well. Thank you.” Customer, Surrey
“I unreservedly recommend ASL. All the glowing reviews of ASL are true. They had to lift paving slabs to fix my drains, and I was concerned there might be unavoidable damage. I should not have worried. Liam and Richard did a superb job. Thanks, ASL” Customer, Surrey
“Darren arrived very promptly and got to work quickly. He did an excellent job and explained what he was doing. We would have no hesitation in recommending ASL Services.” Customer, Surrey
“Very efficient to book them to sort out a sewer drain blockage, and the cost was exactly what they quoted. Called before they arrived with a clear ETA. Got on with the job and sorted it out within the hour. Darren was excellent – very courteous and helpful, did more than we expected to help sort the problem out and was a font of knowledge on all things sewer-related. Given the subject matter (eeew) the whole experience with ASL was an absolute pleasure.” Customer, Surrey
“ASL recently carried out a drain repair at our house. They responded quickly to the call for help, came out and soon diagnosed the problem – tree roots blocking the drain. The remedial work on site was carried out by Lester and George – they worked hard and were very thorough. This is a long-established company that seems to know what they are doing.” Customer, Surrey
Areas we cover
Surrey, Hampshire, Berkshire, West Sussex and South West London
The ASL Limited HQ is in Guildford, but our operating area is the whole of Surrey and parts of Berkshire, Hampshire, West Sussex and South West London.
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Contact Us
Get in touch today
You can call us on 0800 181 684, email info@asllimited.co.uk or use the form below:
