A vine covering a facade and climbing 8, 12, or 20 metres from the ground to the sky is a bit more impressive than a small trellised climber at the base of a building. High greening projects have particularly compelling ecological advantages: filtration of fine particles, reduction of the ambient temperature by evapotransportation, improvement of thermal and sound insualation. Particularly with this type of greening, implementation and sustainability depend on precise design and planning, stable climbing aids, and regular maintenance. For more examples, see Bauhaus style/modern architecture, large walls, balconies, and post/masts.
High facade gardens can be created with or without a support system. In the first case, the aim is to achieve a big effect with little effort. Self-clinging climbers, like English ivy and Boston ivy, are a logical choice. To avoid structural damage, many builders resort to climbing plants that are "tamed" by trellises. Whether the taming and shaping of a plant really takes place depends on its maintenance. The following plants are suitable: annuals, hops, akebia, Dutchman's pipe, clematis vitalba, and 'wild' (fruitless) vines. Vigorous twiners like wisteria, fleece vine, and bittersweet need lots of maintenance. If unkempt, these plants accumulate masses of dead and dry foliage that, when close to windows, can be a fire hazard. In case of the freezing-over of wet foliage, these plant masses can be a heavy load spreading across the entire surface, endangering the stability of the system or support. When in doubt, forego vigorous climbing (twining) plants.
In addition to the usual loads caused by cable tension, plant weight, etc.., wind 'loads' must also be taken into account: after growing about 8m high, plants become 'wind catchers,' especially at the upper corners of buildings. Instead of using plastic fittings (rawl plugs) here, composite mortar or metric fittings would be better. Particularly at risk again are vigorously-growing plants with thick foliage that are not trimmed regularly, as they then offer an inviting surface for winds to strike.
Vandalism can be expected if greening is done in rough neighborhoods of a city or in areas which are hard to supervise. For this reason, FassadenGrün recommends first and foremost rope systems in the heavy and massive construction styles. To prevent the stepping and weight support for potential vandals -- the "ladder effect" -- use horizontal ropes or other trellis elements starting only at a height of about 1.8 metres, or even 2.5 m, as described for cable system 4030. If required, the plants can then be trained with strong bamboo sticks.
High climbing systems made of metal may need to be attached to the lightning protection system of a house or building, if such exists and is required. This is all the more so if the metal trellis structure:
• is massive and rises up to roof height
• is on a building which is exposed to lightning strikes
• is located on a building that towers over others, or otherwise is exposed to lightning and is made of combustible materials, like wood.
For the lighter trellises from FassadenGrün, a lightning conductor is usually unnecessary, nor are they usually needed with awnings, letterboxes, signposts, and cornice covers made of sheet metal. When in doubt, ask an expert or specialist planner.
Private small-home builders and contractors are well advised to do without a high vertical greening when there are any doubts, or to green only up to about 5 metres high, as here assembly and maintenance can be carried out by means of a single ladder. If professional planning, structural calculation, and all subsequent costs are ensured, however, nothing stands in the way of higher greenings!