Accessibility

Accessibility is achieved when the walkable upper drainage level (paving level) finishes as flush as possible with the door entrance. Threshold heights of up to 20 mm above the paving level are considered "barrier-free".

Minimising the water height

In order to keep the water height on the upper drainage level below the threshold height, the majority of the rainwater must be conveyed to the lower drainage level as quickly as possible - for example through open joints, linear drainage and lateral channels or raised gratings.

LORO-X balcony drains with two drainage levels therefore take up the majority of the rainwater via the drainage ring from the lower drainage level and minimise the water height on the upper drainage level.

Performance verification with a discharge curve

In order to be able to verify the discharge performance of the balcony drainage even at water heights below 20 mm on the upper drainage level, performance verifications with a measured discharge curve in the LX data sheet are a basic prerequisite.

Since the rules for barrier-free transitions are not yet specified in detail in current standards, it is advantageous if the manufacturer of the balcony drainage system is consulted as early as the planning phase.

Suitable measures

The following measures can be used to minimise the water height on the balcony and maximise the discharge to the balcony drain.

• Provide adequately dimensioned balcony drains
• Provide backflow protection from the underground drain (HSÜ)
• Take facade water into account
• Position drains at the low points
• Free flow paths to the drain on the lower drainage level
• Communicating main and emergency drainage
• Main and emergency drainage must be installed at a distance <10.0 m from the barrier-free transition
• Emergency drainage
  • Take heavy rainfall events into account
  • Design balcony emergency drains for the complete once-in-a-century rainfall
  • The flooding edge of the emergency drainage must be installed at least 5 cm lower than the upper end of the liquid plastic at the threshold profile
  • For the design of the emergency drainage, the backwater height/pressure head may be considered with a maximum of 35 mm
  • Functional height of the emergency drainage below the door entrance edge
• Driving-rain protection by means of a roof overhang
• The coverings should have a gradient >1% from the connection to the drainage devices (drains/scuppers)
• Gradient of the water-bearing level (2-5%)
• The connection should be carried out with liquid plastic, which can be applied without mechanical fixing
• Avoid soiling or snow/frost at the main drain
• Regular maintenance/inspection
• Insulation and, where necessary, trace heating in case of risk of frost
• From snow load zone 3 onwards, gutters, drains for the main and emergency drainage, scuppers and lateral channels must be designed with heating
• Raised gratings with through-flow to the balcony drain
• Lateral channels
  • For coverings on a bedding layer (gravel or grit, each unbound):
  • The executed gradient of the waterproofing towards the main drainage should be >1%
  • Installation of a drainage mat with a thickness >1.5 cm beneath the bedding layer
  • Installation of lateral channels with a rectangular cross-sectional area >20 cm2 at a distance of max. 2.1 m from one another

References to standards

• Threshold heights below 5 cm constitute "special waterproofing solutions" that require an agreement with the building owners.
• The waterproofing height of the membranes or liquid plastics should reach at least the maximum permissible water height and be secured against under-running.
• DIN 18531-1 sec. 6.6: "In the case of roof terraces with a closed parapet, emergency overflows are to be arranged in such a way that, if the drain becomes blocked, the door threshold cannot be flooded."
• DIN 18531-3: "For barrier-free door connections and connections with a reduced connection height, suitable measures must be provided to avoid splash-water loading and standing water in the connection area, e.g. drainage channels with grating covers."
• Flat-roof guidelines sec. 4.4 "Connections at doors"
• DIN 18040