Channel Drainage Paved Area
Bulb Help & Advice

Channel Drainage Explained

Drainage channels are a great way to move surface water away from paved areas such as driveways and patios. Learn more about channel drain in this article.
Watch How to choose the right drainage channel for your project on YouTube.

What Is Channel Drainage?

Channel drainage, also known as linear drainage, is a popular choice for many buildings projects due to the fact it’s simple to design and easy to install.

Linear drainage is also a cheaper option for surface water drainage than a typical point water drainage system and aesthetically, can be discreet, or a design statement – the choice is yours.

Channel drains typically consist of a channel and a removable grate. You may also need sumps, end caps and other accessories to complete the installation of a linear drain.

Types of channel drains

Polypropylene (plastic)
Polymer concrete
Metal (a good choice for wet rooms, showers etc.)

Types of Grating

Polypropylene (plastic)
Ductile iron
Cast iron
Stainless steel
Stainless ductile
Galvanised steel

These grates can be:

These grates can be:

Heel guard (to prevent shoe heels from becoming stuck in the grate)






One other type of channel drain is the slot drain. This is the most discrete form of channel drain, great for paved-over areas.


What Is The Purpose Of Channel Drainage?

By using a channel rather than a mosaic of strategic point drains, you reduce or even eliminate ponding and deal with heavy run-off such as flash flooding and heavy downpours more effectively. Linear drainage allows for increased area cover in a more discreet way as the drain channels can be longer, and they’re efficient at controlling water flow, by decreasing the pressure put on the system drainage.


Easy to Design

When laying channel drainage, no complicated layouts and couplers etc are needed. Conflicts with underground service pipes/cables are more easily avoided. Using a channel system means that the channel can act as both a multiple point drain and a carrier pipe.


Access and Maintenance of Channel Drains

Grates are easy to remove with keys, bolts or locking systems giving you full access to the channel below. Sumps (if needed), have easy to remove buckets and slot drains have access units, easily accessed with lifting keys.


Visual Appeal

Channel drainage can be discrete or part of the design – it’s up to you. Multiple removable grate designs mean that linear drainage can become a feature of the building project if desired. Grates range from floral designs and geometric patterns through to modern minimalistic designs and of course your standard grate designs. Linear drainage provides more choice than other types of drainage when it comes to visual appeal.


How to Choose Channel Drainage

Three key things will determine the type of channel drainage you need:

  1. Capacity – how much water does your channel drain system need to cope with?
  2. Loading – how much weight will be placed on your channel drains?
  3. Aesthetics – what do you want your channel drainage to look like?

1. Choose the depth of channel you require for the expected flow of drainage water. Depths range from 50mm (34cm² hydraul.section) to 650mm (1,380cm² hydraul. section).

2. Choose your load class rating. 

Infographic demonstrating load classes.

3. Choose your grating (loading will play a part in what is available).

Types of channel drain grating

ULMA Channel Drainage – A Perfect Solution

ULMA provides a superior system that suits any aspect of your channel drainage needs. With a vast range of sizes and load classes, Drainfast is proud to be a major UK stockist of the complete ULMA catalogue.


ULMA Benefits

  • Vast range of polymer concrete channel drains; the best range of EN-1433 certified channel drain on the market
  • Best of class Superior Locking System available on most ranges
  • Near zero water absorption and super-fast flow rate
  • Chemical resistant and unaffected by freezing/thawing cycles
  • Excellent pricing and technical backup
  • Huge stockholding in strategic Depots available for super-quick delivery
  • Rely on Drainfast’s excellent customer service to help your project run smoothly.



More help & advice

Truck Delivery options

Enter your postcode for delivery timescales, accurate stock levels, and your nearest depot