A good subsurface is decisive
The benchmark for durability, efficiency and ultimately, sustainable use
Milling, bush hammering and grinding are common subsur-face preparation processes for flooring. The goal of subsur-face preparation is to ensure the best possible surface ad-hesive tensile strength.
Cracks, hollows, loosened flooring, a ruptured and broken floor, severe weathering due to temperature differences and blistering are indications of poor subsurface preparation. Factory halls, warehouses or production facilities may then exhibit deficiencies which can even endanger production reliability.
Adhesive tensile strength is the benchmark
Aside from the fact that, in rare cases, the floor structure, concrete quality or coating selected is unsuitable, or loads have altered, the grounds for deficiencies are usually to be found in unprofessional or inadequately effective subsurface preparation.
Particularly in the industrial sector, the quality of subsurface preparation is the benchmark for durability, efficiency and, ultimately, sustainable use of industrial floors. The goal of subsurface preparation is to systematically and uniformly enlarge the subsurface area in order to improve the surface tensile strength of the covering or coating to be applied.
Milling, bush hammering or grinding are common processes employed in subsurface preparation, particularly in combi-nation with a powerful dust extraction system. A combina-tion of processes may be required and achieve better results, depending on the quality of the subsurface and the intended usage.
Milling for subsurface preparation
Effective removal in depth and levelling of considerable height differences
Milling involves the removal of the flooring surface using rotating cutters. While the cold milling machine is ideal for heavier and deeper removal of irregularities (from approx. 1cm upwards) or damaged subsurface, lamellar milling machines achieve a finer scarifying texture, but not the cutting strength of the cold milling solution.
The advantages of mil-ling are effective removal in depth and the possibility of le-velling even considerable – and undesirable – on-site height differences. One disadvantage can be damage to the subsurfa-ce in areas which are not visible.
Bush hammering
The most dynamic form of subsurface preparation
The tapered tips of bush ham-mering tools break up the sur-face, but avoid the effects of impacting forces on the subsurface and any lasting damage to the structure. Bush hammering of a surface achieves a roughness comparable with that of a shot blasted surface. This technique employs bush hammering rollers, and it may be described as a dynamic form of mechanical subsurface preparation.
The advantage achieved is the removal of rela-tively coarse material which is easy to suction and does not block any pores. In contrast to shot blasting, no "streaking" occurs and, consequently, reprocessing is unnecessary. High tool costs can be incurred in the case of larger areas, depen-ding on the quality of the subsurface.
Grinding for subsurface preparation
Best adhesive strength in combination with professional dust extraction
Grinding is realised in a horizontal motion on the surface with the aid of diamond tools. Diamond grit, which is primar-ily embedded in metal, cuts into the subsurface, carefully and gently removing material. When it comes to refurbishing floors, grinding has now become a truly effective alternative. As a process, grinding is gentle to floors, achieves extremely even results and minimises reworking efforts (e.g. filling). However, the user must have extensive knowledge and ex-perience in order to select the right tool each time.
When it comes to large areas in particular, we recommend combining grinding with a professional dust extraction sys-tem, as internal testing has shown that the best adhesive tensile strength values are achieved in this manner.
A very considerable reduction in dust generated during working is achieved through combination with high-performance industrial vacuum units. In addition to redu-cing the risk to health, this also achieves a working result which means considerably less effort during final processing, due to the removal of dust. Thanks to their broad machining range and, no less important, the fact that remote control is now possible, grinders not only permit ergono-mic working, but also a high hour-ly surface machining rate.
For the renovation of floors is grinding an economical alternative
Overview of processes and machines by area size
Subsurface preparation with Schwamborn construction machines
