Irrigation of Green Roofs

XF301 Sedum Blanket installed on falls.

The effects of climate change are becoming increasingly significant factors for green roofs. Recent years have seen higher summer temperatures and longer periods of hot, dry weather.

To reflect these changing conditions, Bauder has updated both its specifications and the advice provided to clients.

Irrigation

Bauder's advice has always been that all green roofs require water during periods of drought.

The primary cause of green roof failure is a lack of watering, either during the establishment period immediately following installation or later during extended dry spells.

Bauder now recommends that all green roofs have either a permanent irrigation system or a suitable means of watering the roof during drought conditions.

For smaller schemes and domestic installations, this may simply be a suitably located tap point that allows the roof to be watered manually.

For larger commercial projects, a permanent irrigation system is recommended.

Bauder has a number of documents detailing the aftercare and watering requirements for our green roof systems:

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• It is recommended that installing contractors issue aftercare guidance to the Client, Main Contractor and end user so that all parties are aware of the watering and maintenance requirements of the roof.

  
  

  In addition, installers should maintain a full photographic record of the roof and the condition of the vegetation at the point of handover.

  Installation of Bauder XF301 Sedum Blanket on Pitched Roofs

  Bauder continues to require SDF drainage mat to be installed beneath XF301 Sedum Blanket on flat roofs with falls of less than 1:50 (below 2°).

  However, green roofs installed on roofs with a positive fall greater than 1:50 (over 2°) no longer require the installation of SDF drainage mat beneath the XF301 Sedum Blanket.

  Important Note

  The removal of the SDF drainage mat assumes that the roof drains freely and does not retain standing water.

  SDF drainage mat must always be installed where, following construction, it becomes apparent that there is a risk of standing water occurring on the roof surface.

  If you require further information or have any green roof queries,