Beginners guide to linear drainage systems (incl. slot drains & channel drains)

If you’ve ever wondered what the difference is between channel drainage, slot drain or linear drain or if they’re just one and the same, you’re not alone. Here’s a useful guide to the different types of surface water management systems available.

What is Surface Water Management and Linear Drainage Systems?

Surface water management is the process of managing the course water takes over land to prevent flooding. Surface water flooding occurs when intense rainfall overwhelms drainage capacities. Good surface water management is about making sure that rain can drain effectively through our environment.

There are a number of different methods used to manage surface water runoff, including linear drainage systems like channel drainage and slot drains, traditional gullys, open dish channels and french drains. Channel drainage, linear drainage and slot drainage are often used interchangeably to describe linear drainage systems but there are distinct differences between them.  Collectively they are all Linear drainage systems, meaning they collect surface water runoff along their entire length, as opposed to traditional gullies which collect at single small points.

What is Channel Drainage?

A channel drain, is a type of linear drain, for removing large quantities of water from a paved, tarmac or concrete area. This is a generic term for linear systems that incorporates a channel together with an inlet detail that is embedded in the constructed surface.

Key distinctions include:

• Typically consists of an open channel cover by a removable grate
• The channel is longer than it is wide with a cross-sectional dimension design to contain the flow from the associated surface surrounding the installation
• Channel drains are typically structural formers that are integral to the performance of the system but may or may not be load bearing without the required surround detail

The channel body of these systems can be manufactured in Polymer Concrete, Concrete Plastic or Steel. Whilst the grate can be manufactured in Polypropylene (plastic), Ductile iron, Cast iron, Stainless steel, Stainless ductile, Galvanised steel, Aluminium or Concrete/stone. The grates can also be heel guard (to prevent shoe heels from becoming stuck in the grate), perforated, slotted, decorative, solid and permeable.

Channel drainage can be used on pathways and driveways, car parks, commercial settings, swimming pools and sports areas and many more places.

What is a Slot Drain?

A slot drain is another type of linear drain, also for surface water collection. A slot drain is different from the traditional drain in the sense that it does not have a removable grate. Its narrow slot design also means it is less visible when installed, which is preferred when you are looking to achieve a great aesthetic finish.

Key distinctions include:

• Does not have any kind of removable grate
• Slot describes its appearance in the ground – making it less obtrusive and providing a more superior aesthetic finish
• It is often used in areas subject to heavy loading where it is important to eliminate moveable parts
• More advanced forms of slot systems, although not load bearing in their own right, are formers that facilitate the construction of a ‘non-interrupted’ pavement
  

As with channel systems, the materials used to manufacture slot drains can vary from polymer concrete to plastic and steel.

Slot drain can be used on pathways and driveways, car parks, commercial settings, airports, ports and many more places.

Why use a Slot Drain over a standard Channel Drain?

Here’s some of the key advantages of slot drain over channel drain:

1. Sleeker design
   In contrast to channel drainage, which is wider and covered in heavy grates, slot drains are much narrower with less material visible. Their less obtrusive design makes them more aesthetically pleasing.
2. More cost effective
   When it comes to maintenance, slot drains are considered much easier to clean. As you only need to clean the drain itself, without worrying about also removing the grate and cleaning that too, it takes less time to clean, saving you on costs.
3. Control odour
   Channel drains have much wider channels and often they are also not sloped, which means standing water and sediment can build up over time, leading to bad smells. As they are also harder to clean, there is also the possibility of residue waste not being completely removed.
4. Fewer replacements
   Over time grates can begin to deteriorate and corrode, making them less effective in protecting your drainage system. With a slot system, no grates are required so you don’t need to worry about their condition.
5. Safer
   The heavy nature of grates in channel drain systems means that they are difficult to remove and if done incorrectly can lead to injury. Grates can also break from wear-and-tear or by having too heavy of a load placed on them.

At Cotterill Civils, we supply a wide range of surface water management systems. These include both channel drainage and slot drain systems from some of the UK’s leading manufacturers.

To view our surface water management products. click here.

Speak to our team of specialists to get expert advice on which system is best for your application. Call us today on 0121 351 3230