Green roofs are green areas on urban buildings. As space becomes more of a premium, designers are integrating green roofs to optimize a buildings living and community spaces.

Green roofs help to reduce the urban heat island effect by reducing the concrete spaces within a city. Unlike vegetation, concrete absorbs heat which contributes to urban deterioration (slabs and roads break down much quicker), high energy costs because buildings get hotter and require additional cooling etc.

Green roofs can be paved, gardens, pools, play spaces – or a mix of them all!

Draining a green roof with soft bedding is a challenge. Drainage is vital so plants and vegetation can drain properly and also to protect the buildings integrity from standing water.

When considering drainage for soft bedded areas, key things to consider is how deep is the soil or gravel and how the drainage element will interface with the waterproof membrane.

“Ag” pipe, short for agricultural pipe, is a common way to drain green roofs. It is cost effective, but only deals with subsurface water (water collecting below the surface). An alternative to ag pipe and surface drainage is a combined surface and subsurface drainage system: ACO ProfiLine.

During heavy rain, the landscaping will become saturated and both surface and infiltrated runoff can be directed towards the channel which discharges drain a roof or floor drain. An access grate permits entry for maintenance to the main stormwater connection.

During light rain, the water runoff from the surface or façade will percolate out of the channel side walls and help irrigate the landscape. The perforations in the channel are also an effective precaution should the outlet of the drain get blocked as the surrounding area acts as overflow storage.

Click here to learn more about ACO ProfiLine.