Mainka at a glance
Total output 2025
> 330
€ million p.a.
Founded
1895/1949
Branches
- Lingen (head office)
- Brunsbüttel
- Gelsenkirchen
- Cologne
- Münster
- Osnabrück
- Papenburg
- Wuppertal
Mainka employees
> 750
Accident statistics
Construction projects for chemicals, energy and logistics
We plan, construct, renovate and maintain industrial buildings safely, reliably and with many years of experience. Our focus is on complex projects in sensitive industrial environments such as chemical parks, power stations, refineries, energy infrastructure and large logistics sites.
Renovation and redesign of the building complex
Renovation of the Historic Kasino
For our client Bayer, we carried out a comprehensive refurbishment of the historic Kasino building in Leverkusen — including the hotel and event areas. The works included the complete replacement of the slate roofing, renewal of the ventilation and climate‑control systems, as well as extensive interior fit‑out.
A particular challenge was that the renovation took place within the existing building structure and without disrupting the ongoing canteen operations. In addition, the hotel automation system was modernised to ensure maximum comfort and sustainable operation. After completion, the building now shines with state‑of‑the‑art technical installations while preserving its historic character — crowned by the return of the restored weather vane.
Figures and facts:
- Detailed design
- Earthworks
- sewer / pipeline construction
- Reinforced concrete works
- Road works
- Concrete works
- Formwork and reinforcement works
- Technical building equipment
- Interior works
- Production of media-tight surfaces
- finishing works
- Work during operation
- Facade works
- Paving
- 5,000 m² GFA
- Renovation and complete replacement of the existing slate roof covering
- Replacement of the complete ventilation and air conditioning system
- Conversion of the existing building without restricting ongoing canteen operations
| Customer | Bayer AG |
|---|---|
| Location | Leverkusen |
| Contract value | €35 million |
| Main construction period | 23 months |
Similar references
Of our more than 750 employees, around 60% are construction site personnel, whom we train regularly. On average, we devote 2% of annual working hours to training.
For whom and why?
We generate more than 90% of our turnover in the chemical, energy and specialised logistics sectors. Customers from these sectors trust in our experience because we construct complex industrial buildings reliably and safely.
