In public buildings, barrier-free entrance doors are always provided.
The transition from living areas to roof terraces, balconies or loggias, which should be as level as possible, as well as the stepless building entrance area are critical construction points that must be carefully detailed, as moisture damage can occur very quickly due to weather influences (driving rain, snowbag formation). Already in the early planning phase, all boundary conditions should be taken into account, e.g. interior and exterior construction thicknesses, ceiling offset and slope.
The barrier-free transition from buildings to the outdoors often leads to conflicts with technical regulations. There are tried and tested solutions for this, but they do not conform to all points of the directive: By laying external drainage channels parallel to the door, protection against moisture can be fulfilled without a major difference in height between the external and internal levels.
The demand not only contradict the formulated requirements for barrier-free construction, but were and are equally regarded as impractical by numerous architects, property managers and flat users. Large threshold heights are undesirable in many circles and are not implemented.
All experience gained in reducing the connection height from 15 cm to 5 cm should be used. Procedure for planning barrier-free door thresholds:
Evaluation of a planned threshold formation:
- Hydraulic calculation of a drainage channel must be available
- Existence of a roof, a closed parapet or lateral weather protection can be supportive
- Check and observe alignment and main wind direction
Evaluation of the surface drainage:
- An elevated surface covering with min. 3 cm free space for horizontal drainage is recommended here.
- Supporting the gravel or chippings layer with drainage mats or spur channels already brings a clear improvement here.
- Drainage layers consisting only of chippings or gravel have the lowest drainage performance and are most unsafe due to contamination
- A planned slope of at least 2% of all water-bearing layers.
- Slope in any case away from the connection point
- At least 2 drainage points are to be provided
- An emergency overflow can be used as a second drainage point
- Use of mesh gratings (mesh 30x10, the longer mesh size across the direction of travel).
- More than 50% free opening cross-section
- Minimum slot width of 8 mm
- A dirt fleece underneath the grating is not advisable under any circumstances; the whole system loses its function if the mesh becomes clogged.
Barrier-free lower door stops and thresholds:
- The tightness of lower door stops can be achieved by using special rubber profile seals or magnetic door seals.
- The seal must be secured against running behind the door profile.
- The sealing height incl. door profile should be at least up to the upper edge of the gutter system.
- Maximum height 2cm
Essential contents have been taken from the book "Schäden an Balonen" (Damage to Balconies) in cooperation with and with the kind permission of the author
Dipl.-Ing. Nils Oster, Ö.B.U.V. expert, the book "Schäden an Balonen" ("Damage to Balconies")
from the series "Schadenfreies Bauen" of the Frauenhofer IRB Verlag.