190 balconies on a bridge - certified waterproof membrane for floor level building elements

Construction waterproofing in the lousy Wilhelmshaven weather – SCHOMBURG also waterproofs difficult projects

Wilhelmshaven can be strange. An example? A bridge without pillars, named after the state capital of Hessen is not really commonplace. But still the Wiesbaden bridge is on every city map of the lower Saxony coastal resort and even with it being in the middle of the inner harbour. The solution is simple: the ominous bridge is about a tongue of land in the harbour, named after the imperial warship “Wiesbaden“. Such elongated harbour tongues are also called “bridges”. Together with the installation company, Abdichtung Oldenburg Olaf Kannwischer, the Detmold based producer of system based construction products SCHOMBURG helped realize the showcase building there for the Spar + Bau residential building cooperative. Then there were only a few specialists in the running for a waterproof solution for the floor level windows and door units.

300 apartments were to be generated on the former “coal tongue” in the inner harbour. Where previously warships were furnished with the necessary fuel, people would live in the future. The view over the Jade bight is spectacular – just as spectacular are certainly the weather conditions, which would gnaw at the building materials. On average the coastal town experiences 199 rainy days per year. SCHOMBURG delivered 2.9 tonnes of the rapid mineral-based construction waterproofing product AQUAFIN-RB400 and waterproofed around 190 balconies.

The reactive construction waterproofing product AQUAFIN-RB400 ensures that the transition between the floor level windows and the building fabric remains watertight. The planners can be certain that it works, then AQUAFIN-RB400 is the only mineral-based construction waterproofing product, whose watertightness for “waterproofing of floor level door and window units” can be substantiated through an official certificate from the material testing establishment for the building industry in Braunschweig.

AQUAFIN-RB400 is quick to use as its chemical structure rapidly cures through a self cross-linking process. After only three hours it is rainproof, can be subjected to foot traffic and further work processes. It even bonds to damp substrates. Drying is therefore not dependent on the weather and, even in damp climates, waterproofing measures can be carried out as planned. It can be painted or rendered over without problem, which is not unimportant in visual areas like balconies.

In the wind and weather of the north German coast there is an additional plus point: the client can be certain that AQUAFIN-RB400 is frost and UV resistant – even remaining reliably watertight after years. In Wilhelmshaven the client profited as waterproofing with AQUAFIN-RB400 was already planned at an early stage. Prior to the installation of the cladding, the splash zones and building skirts of the facades were prepared with AQUAFIN-RB400. After completion of the building shell, the floor level window units were progressively installed. As part of further processes in the building programme, successive waterproofing to the window units was produced and connected with the waterproofing already applied to the splash water and building skirt zones.

Everything was compatible and planned from the start. The planner of this large building project especially profited from the system solution. That does not mean that the rapid mineral-based construction waterproofing product AQUAFIN-RB400 is limited to new build projects. Renovation projects can also be waterproofed with it and can often revise past errors.

Also on board with the Wiesbaden bridge building project: SCHOMBURGs AQUAFIN-1K, the rigid waterproofing slurry. A total of 8.4 tonnes of it had been installed by the end of the project in the Jade bight. The pre-waterproofing ensures, as it were, a last ounce of security in the construction. AQUAFIN-1K resists negative water pressure up to 1.5 Bar and can be trowel or spray applied. Therefore it can also be mechanically applied, which is very practical for large projects such as that at the Wiesbaden bridge.

A combination of almost one linear Kilometre of waterproof tapes were installed in order to get the balconies waterproof against the lousy north German weather. The first of a total of three building phases has since been completed with the project scheduled for completion in early 2022.

Interview
Three questions to Lars Albrecht, technical department at SCHOMBURG:

Herr Albrecht, why was the Wiesbaden bridge a particular challenge for the materials and above all the building products?
There were alone 2,500 square metres of concrete surfaces to waterproof – that needed to be solved first. As a supplier of system solutions we were already switched on early and advised at the planning stage in order to develop a first class and economical solution for the customer. It is somewhat different to build on the coast than on flat land.

So SCHOMBURG was there at the beginning?
Almost. Right at the start sample balconies were flooded in order to test the quality of the construction waterproofing materials under real conditions. With 190 balconies that should be done. A competitor’s product failed so together with the installation company, Abdichtung Oldenburg Olaf Kannwischer, SCHOMBURG was then on board as the solver of the problem.

In addition to permanency, did other aspects play a role?
Yes, especially sustainability, which is always an important sales argument. Our mineral-based waterproofing slurry AQUAFIN-1K is supplied in plastic bags, which can not only be completely emptied but they can also be stored without problem in the rain on site. And: the empty bags are collected by Interseroh and therefore reliably recycled.