System construction "Balkurapid" Balcony renovation in a residential apartment building

  • Building Type: Residential Construction
  • Pad: Coverings and Tiles
  • Solution: Fast-Track Installation Systems, Restoration of Old Subfloors
  • Brand: Codex
  • City: 80000
  • Country: International

The task and the challenge for the construction chemicals specialist codex was and is to counter and work around the trend "away from exterior use of ceramic tiles" using new techniques and well conceived systems. As we all know, houses and apartments with balconies sell better, they are more appealing as they are more visually attractive, and they give the comfortable impression of a closer connection to nature. Simply, balconies and terraces are places associated with relaxation and rest – our individual place in the sun.

Sadly, more and more often they are built without ceramic tiling despite that this type of covering brings outstanding properties when used outdoors. That exterior ceramic tiling is exposed to the highest demands, and that the risk of damage is therefore considerably increased, is undeniable. However, to simply throw in the towel because of this damage, and to maintain that the outdoor installation of ceramic tiles is no longer practical, is certainly wrong. The range of causes of the damage is very wide and has already been covered in detail in many articles and papers.

For the technical division of Uzin Utz AG, the challenge was not to find another cause of damage but rather a solution to the problem of developing "exterior use of ceramic tiles". This was realised in co-operation with the company Gutjahr under the name of "Balkurapid".

For several years already, throughout the Federal Republic, test balconies and terraces have been installed and monitored. Even after years, the results have been positive and in line with expectations. Now the Balkurapid-System must also be introduced to the general market. Together with the specialist company, Fliesen Singer from Bad Feilnbach, 20 balconies in a project within the city of Munich were refurbished.

Braving the unknown?

For a long time it had been the wish of the tenants and owners of the apartment building in the inner city of Munich to have their balconies modernised. This wish was in view of the fact that, 30 years ago, clinker tiles had been laid on asphalt, quite understandably. But, whoever assumes that they would find only damaged tiles is mistaken. Contrary to all experiences, this was not the case.

The first challenge was to convince the occupiers about the new Balkurapid-System. In this it was clear how important and decisive for the overall success is the co-operation between the tradesman, the manufacturer, the supplier and the planner. Braving the unknown is pushed quickly to its limits if you don’t prepare in consultation with technical advisers and the end-users. This requirement was clear! Now it was time to dispense with previous experience and get on with some convincing work. As the system meets all the requirements of the construction management, once the contract was awarded, work could begin. To refurbish the damaged cantilever balconies, a special contractor was brought in who repaired areas where weak sections of the concrete were removed using special products. Only then could Fliesen Singer GmbH, who gave a refurbishment time estimate of five weeks, begin the new construction work. It was first of all necessary to create the falls of approx. 2% in accordance with building standards. By way of preparation, surfaces were primed with Fliesengrund from codex, an edge expansion-strip was fitted, thickness guides were placed and, with NC 395 at around two centimetres thick at the centre-point, the ramped screed was installed.

Immediately after a drying time of only three hours under the prevailing general conditions, the fitting of the drain end-connection profiles could begin. For this, when the bonded screed was laid, the leading edge was deepened to avoid a height protrusion of the profile. From now on, it went at top speed: fitting and bedding in of the profiles, cutting in and loose-lay of the RR 185 sheet membrane, waterproofing with the two seal-tape products, "BST 150" and "BST 75".

Now the system drainage grids, as well as the reinforced Watec 4 E thin drainage mat, including the Watec FS joint cover-strips, are loose fitted. Walls and doorways should, in planning, always receive special consideration. So that moisture cannot migrate behind the skirtings, it is recommended that these should be fitted flush to the plaster.

For the installation of the 25/25 clinker tiles, the flow-bed mortar Power Fluxx (with Power Mix additive) is used. After sufficient drying of the mortar, they can be grouted using rapid grout mortar Brillant Flex. The formation of the connection joints is with silicone mastic sealant D80 which, whilst still fresh, is scattered with fine quartz sand from Uzin and this is lightly rubbed in.

In the refurbishment of balconies and terraces in residential blocks there can be only a comparatively small investment in time and transport. Firstly, any old and still bonded tiles do not necessarily have to be broken out but can, if necessary, be smoothed over as this system has a very low construction height of between 20 and 25 millimetres (depending ontile thickness). Secondly, many of the components are semi-ready products that do not have to be mixed. Therefore, this reduces the time spent in erecting and moving equipment and machinery. For the occupiers, "braving the unknown" paid off as they can now enjoy the springtime and the associated use of their balconies.

The early scepticism of the participants, as can be seen with hindsight, was completely unfounded. Master tiler Martin Singer made the point. "Both my colleagues and I were able to maintain the prescribed time-plan with no problem due to good planning and the easy and fast to install Balkurapid-System. I am convinced that, with this system, we can counteract the downward trend for using ceramics outdoors.  For me as an independent tiling specialist, the satisfaction of the customer is the top priority. On this project, that demand was met outright. The customer now has no need to do without his beloved ceramic tiling in outdoor locations."

Of course, the five-year "Balkurapid" guarantee partnership between Gutjahr and codex also applies for fine stoneware tiles.