Initially, the roof area was divided into two part-areas. For each of these areas a separate low point line was planned. Along these two lines, 5 main drains and 9 emergency drains should be installed that were partly connected to a horizontal collector pipe in the building. This option, however, would have meant a great amount of work, respective tapping holes through the roof, sealings and long pipelines in the interior of the building.

Together with the responsible planner the following objectives were set: to reduce the number of drains and roof penetrations, to simplify the installation of the pipes and to move the pipes – if possible – from the inside of the building to the outside. There should be as few roof penetrations as possible and the roof incline should be as simple as possible. The major challenge was to combine the two part-areas and to find one common low point line for the whole roof in order to reduce the number of the required draining points. Here, the collaboration with the producer of the gradient insulation is necessary.

With the aid of the basic information on the roof structure suitable roof drains are selected. This selection can take place via the online configurator on www.loro-x.com, for instance.

The selection of the suitable system quickly produced an astonishing result: For the complete area of 1.780 m², 1 LORO-X DRAINJET siphonic drain system for the main drainage as well as 1 system for the emergency drainage with 1 roof drain each is sufficient. The most important change, thus, constituted the replanning of the roof incline so that the rainwater can be securely transported from the roof area to the high-performance drainage systems. 

The fact that the proposed emergency drainage system LX961 realizes a discharge rate of up to 94.4 l/s at a water height of 75 mm on the roof, provides increased security in the case of unexpected heavy rain in comparison to the normative calculation on the basis of the average century rainfall.

With aid of the LX specification sheet, system shape and system power of the proposed solution could directly be matched with the construction conditions of the project.

At one glance, the features of the roof drainage system can be found in the practical feature list of the LX specification sheet. With the concise feature list, on the LX specification sheet, complemented by the discharge curve and the system CAD drawing, the planner does not only receive an optimal proof of performance, but simultaneously also a clear illustration of the roof drainage for the processors on the construction site.

With the new planning of the roof incline as one single U-shaped low point line, several wishes were satisfied at the same time:

The amount of work could be reduced significantly. Instead of 14 only 2 LORO-X drains have to be installed in the roof area. The drains are each positioned directly above the downpipe so that there is no need for a horizontal collector pipe in the building. The initial position of the downpipe connection to the rainwater collecting container in the ground could be maintained. The weather-resistant, break-proof, backflow-proof and optically attractive downpipe made of galvanized steel is installed at the outside of the front building and thus not in the building anymore.

The complete installation of both roof drainage systems took place outside via the open, roofed corridor. That way, the downpipe made of weather-resistant and break-proof LORO-X steel discharge pipe could be installed without any problem. In order to optimally provide the LORO-X DRAINJET roof drains, with the convenient clamping flange as loose and fixed flange construction, with water, the low point line has been widened at the drainage points to secure a circumferential inflow. Due to the newly planned low point line, the required “height” of the gradient insulation could be significantly reduced because the distances between low and high points could be reduced.