Effective drainage must be front of mind for creating new gardens and patios or landscaping over existing spaces. Over this four-part series, Rob Butcher, Design Services Manager at ACO Water Management will look at the key considerations landscapers need to have in mind and plan around when implementing threshold drainage.
The integration of outdoor and indoor spaces is a crucial element for any building, and this couldn’t be more applicable to the current trends in home design. A growing number of homeowners embrace the idea of having a step-free level walkthrough from their indoor space onto the patio. Given this, more emphasis is required on threshold drainage to avoid unwanted – and often dangerous – water ponding. There are several considerations here, but the first to start with is the property’s damp proof course.
Do not butt drainage up against the damp proof course
Before approaching threshold drainage, the damp-proof course (DPC) is a construction element that needs to be kept in mind. Integral to protecting the property from structural damage, if it is placed too low or the ground is being built up too high, damp can infiltrate the dwelling as rainwater breaches the DPC.
A common misconception is that a drainage channel can be installed directly against the DPC to prevent this problem arising. However, this is not true – as the drainage channel’s grating would be at the same level, rainwater will continue to splash and permeate the brickwork above – proving to be a counterproductive approach. Furthermore, such a measure has the potential to make matters worse, as an environment is created between the wall and the channel for vegetation to grow. Moss may start to develop along the wall which could eventually breach the DPC and leave the brickwork in an increasingly vulnerable condition.
For homeowners looking at a implementing a level threshold, an elevated DPC provides an added buffer that can decrease the risk of breaches and rising damp.
For more information on threshold drainage and the solutions available, visit https://www.aco.co.uk/building_threshold