Between April and July, a technically demanding polyurea floor coating was applied to a total area of 2,700 m² in a multi-storey building in Bern. What looks like a routine job from the outside was anything but ordinary in the execution - especially due to the special protective suits and equipment reminiscent of a space mission. But instead of weightlessness, the focus here was on precision, material knowledge and environmental conditions.
The process at a glance
1. preparation and surface treatment
First, all surfaces that were not to be coated were carefully masked off. This was followed by shot blasting - an effective method for mechanically cleaning and roughening the concrete. The residues were then thoroughly removed.
2. grinding work and slope formation
The wall curbs were sanded to create clean transitions. Counter-slopes were modeled around pillars and along the concrete walls using epoxy mortar - important for later drainage. The entire floor surface was then also leveled with epoxy mortar.
3. primer and quartz sand scattering
After cleaning, either a primer coat of Sikafloor 151 or a scratch coat was applied. In both cases, the surface was then generously coated with Quartz sand (0.7-1.2mm) to create a non-slip surface. After curing, the excess sand was removed.
Polyurea application - the centerpiece of the projects
The application of the Sika 8800 polyurea system was the central work step.
+ First layer: At least 2 mm, in places up to 4 mm thick
+ Second layer: approx. 1 mm, sprinkled with normal corundum (0.6-0.85 mm) in excess
This two-layer system ensures a resistant, waterproof and mechanically resilient surface. After curing, the excess grit was vacuumed off again.
Finishing and sealing
As a final layer, a sealant with Sikafloor 390 in the color RAL 7032 (pebble gray) was applied. This not only protects the coating, but also gives the floor a clean, professional look.
Technical requirements and challenges
A critical success factor in this project was the constant monitoring of the environmental conditions:
+ temperature
+ humidity
+ dew point
These had to remain within the tolerance range during the entire construction period so as not to jeopardize the quality of the coating. Technical problems arose occasionally, but were solved quickly - the team was prepared accordingly.
Why polyurea?
The use of polyurea as a coating system has clear advantages - especially in areas subject to heavy wear, such as in this building. Polyurea hardens within seconds, is seamless, jointless and permanently elastic. It provides reliable protection against moisture, chemicals, abrasion and mechanical stress. The combination of speed, resistance and durability makes it the ideal solution for surfaces that not only need to be functional, but also permanently waterproof and easy to clean.
Polyurea offers decisive added value, especially for multi-storey infrastructures with technical use: a sealed surface that remains stable even under intensive use - without cracks, delamination or moisture damage.
As with a well-planned space mission, every detail was important: precise processes, controlled conditions and a well-coordinated team. The result - 2,700 m² of heavy-duty flooring - stands for technical quality and clean implementation. Mission accomplished.
