General planning information

Roof plantings pose specific challenges for building structure and roof substructure. The following overview covers some of the issues that need to be considered at the planning stage.

Structural analysis
The load-bearing capacity of the roof structure is a key criterion for the planting. Bauder extensive plantings can be created with weights from approx. 70 kg/m² when water-saturated. For intensive plantings, weights of at least 300 kg/m² should be allowed for, plus traffic loads.

Root barrier
Bauder can supply a wide range of root-resistant synthetic and bitumen membranes. The torch-on polymer bitumen membrane BauderSMARAGD, for instance, is a high-quality waterproof capping sheet and root barrier in one.

Connection heights
The requirements set out in the flat roof guidelines must be complied with. The reference height for roof plantings is the upper edge of substrate, gravel or paving slabs. Barrier-free access must be planned separately.

Roof drainage
The water retention and run-off delay for roof plantings is specified in the run-off coefficient and depends on the layer depth. As a result, the roof area that can be connected to a roof drain increases accordingly. The roof drains must be freely accessible for the purpose of inspection and maintenance. This also applies to roof drains in tiled or paved areas. With lightweight roof structures it is particularly important that emergency drainage
requirements are observed.

Roof slope
Ideally between 1° and 5°. Roof structures without any
slope also present no problems for intensive planting; extensive plantings require separate planning. With roof pitches of above 5°, sloping roof planting systems should be used. Bauder sloping roof planting systems can be used with roof pitches of up to 25°.

Roof utilisation
Multifunctional roofs have almost become the norm. Whether solar roof, roof terrace, HVAC or beach parties - the more a roof is used, the more meticulous the planning has to be. It is advantageous to harmonise the different requirements at the earliest possible stage.

Location
Extensive plantings like plenty of sun. Heavily shaded areas pose problems. Intensive plantings can be more easily adapted to different conditions due to the wider Plant range.

Wind uplift
Roof plantings can assume the role of ballast for loose laid waterproofing membranes. Once the plants have developed a mature root system, they impart excellent stability to the substrate. Before the roof is planted drifts may occur, but these can generally be rectified without too much trouble in the course of maintenance. It is advisable to plant the whole roof area as quickly as possible.

Maintenance
Intensive plantings require intensive maintenance, while extensive roof plantings are low-maintenance, but not maintenance-free. Health and safety regulations must be observed - there must, for instance, be attachment points for ropes to safeguard against the risk of falling.

Traffic areas
If pressure-resistant drainage elements are used, it is easy to combine paved areas for foot traffic and roof plantings. Vehicle access places far greater demands on the construction, the entire roof structure and the building itself. Detailed planning is absolutely essential
.