1. Downward Slopes Are Not as Important as You May Think!
One common misconception when it comes to Threshold Drains, is that a slope is required for water to drain effectively. This, however, is not the case!
As long as the channel is laid flat and level and the outlet is below the level of the channel, water will be able to flow.
Whilst water can flow on a flat surface, unfortunately it cannot defy the laws of gravity! Often the team at ACO are presented with designs that include an uphill slope for water to run along.
Of course, there is always going to be a preferred route for runoff water travel, but the logistics of making this happen are close to impossible! Rainwater re-routing channels must be either flat or slope downwards in the desired direction.
Paving channels come in two varieties: gratings and Brickslot. Standard gratings can be easily lifted out of the channel for cleaning and maintenance. Brickslot, on the other hand, needs more thought because the only way to access the channel for maintenance is through the inclusion of dedicated access points, so these units must be included when in the design stage of your drainage project.
Ultimately the choice is yours!
4. Get the Depths and Loads Right Before Installation
Grab a £1 coin and let’s get those depths sorted! To create a paving-friendly setup, the runoff channel should be 3 - 5mm lower than the surface area it is diverting water away from. This is equivalent to placing a £1 coin face down on the channel's surface and the surface area that is the source of the runoff being level with the top of the coin.
When it comes to the load class your Threshold Drain will have to endure, consider what will be travelling over your drainage system, friends and family in the back garden? Then an A 15 solution can be used. If it’s a driveway installation it is likely to cars and other vehicles passing over, opt for a B 125 system, which should be the minimum classification considered.
Don’t worry if this seems a little confusing, team members at our branches are happy to advise you!
It's important that the accompanying drainage adds to – rather than detracts from – the aesthetic appearance of the landscape being created, so carefully selecting the perfect colour of Threshold Drain and accompanying aggregates is key.