Preparatory measures

Before coating, adjacent components such doors, skirting, impact protection rails, corner guards and joint profiles should be taped up with plastic sheeting to protect them from resin splashes. Non-fixed items such as ironwork covers should be removed and stored elsewhere on the site. The applicators will need to fill smaller imperfections in the floor with a fast-reacting mortar and grind the surface flat once it has hardened. Joint edges are reprofiled. Then the surface areas to be coated need to be neatly masked in a straight line. It is best to mix the coating materials at a separate location sheltered from rain and sun and with sheeting protection underfoot as required. It is advisable to ensure ready availability of the daily requirement of materials there to avoid disruption to the work. The requisite placement tools and cleaning materials should also be stored there. Once mixed, the resin is taken in trolleys from the storage and mixing area to the area to be coated.

Mixing

Synthetic resin coatings for multi-storey and underground car parks are usually provided in the form of two-component systems. Before laying, the resin and hardener components are carefully blended together at low speed (approx. 300 - 400 rpm) using a powerful mixing device, for example an anchor stirrer. Compliance with the mixing times recommended in the technical instructions is essential to ensure homogeneity. After mixing, the resin is decanted into a second, clean container and carefully stirred again ("repotting"). The now ready-to-use resin mixture should then be taken immediately to the prepared coating site and used without further delay.

Priming

The first layer of a coating system invariably consists of a primer. This is usually a low-viscosity synthetic resin which is first distributed with rubber squeegees and then massaged into the peened or ground concrete substrate in a crosswise motion with short-pile lambskin rollers. For the best possible adhesion to the following layers, the still liquid, fresh primer may also be lightly sprinkled with kiln-dried quartz sand. This is particularly important if the next layer cannot be applied within the optimal timeframe.

Scratch and Levelling Coat

The scratch coat ensures a high-quality, visually smooth and impermeable surface. For a scratch coat, the resin used for the primer is mixed with fine, dried quartz sand and applied to the primed surface ("scratched"). Depending on the application, rubber blades, steel trowels or hard rubber floats may be used for this purpose. As with the primer, some oven-dried quartz sand may be sprinkled into the still liquid scratch coat before it hardens to roughen its surface. OS 10 and OS 11 coating systems always feature a waterproofing membrane. Consequently, a scratch coat should always be applied and slightly sprinkled with dry-shake sand for such systems so that the membrane forms a non-porous layer of uniform thickness with reliable, firm bonding to the substrate.

Wear Layer

As sloping structures, ramps in multi-storey and underground car parks differ from other trafficked areas. The wear layer on ramps needs to be particularly resistant to the shear stresses caused by accelerating and braking vehicles. Essentially, the wear layer is applied to a ramp in exactly the same way as to a horizontal surface. However, depending on the slope of the ramp, it may be advisable to add a thixotropic agent to the coating materials in order to obtain uniform coating thicknesses throughout. Rather than quartz sand, hard and highly resilient aggregates such as basalt and corundum are often better suited to ramps as the anti-slip dry-shake material. The wear layer on ramps will need to be laid with particular care to ensure a smooth and even appearance.