Grumbach – innovation, competence and experience
Karl Grumbach GmbH & Co KG is today a family-run industrial company in Wetzlar-Münchholzhausen and has been in existence since 1938.
The company specialises in the development, production and distribution of (innovative) sanitary and flat roof products. The sanitary products include prefabricated bathrooms, prefabricated showers (complete showers), sanitary building blocks for pre-wall installation and shower floor systems for the construction of floor-level tiled showers. Flat roof products include roof drains, roof vents and accessories for draining and ventilating flat roofs. GRUMBACH currently offers the largest roof outlet programme in Europe for flat roof drainage.
The family-run company has been developing, producing and selling solutions for practical requirements since 1974. Here is a look at the company’s history:
Attika Corner Drains
GRUMBACH presented a new generation of PUR roof drains at the international DACH+HOLZ 2024 trade fair in Stuttgart: The Attika Corner Drains provide an elegant and efficient solution for flat roof drainage, directly in the corners of the flat roof.
These roof drains are:
- Attika Corner Balcony Drain made of PUR
- Attika Corner Meso Drain made of PUR
On 11 February 2024, the shareholder Hedwig Grumbach died at the age of 88.
Change in the shareholder structure
Simon Gerd Konstantinidis (Master of Science Physics) becomes a shareholder through the purchase of Julia Lengfeld ‘s shares in the company. This means that a family member from the 4th generation is joining the company.
On 23 July 2019, shareholder Rita Günther died unexpectedly at the age of 64.
New prefabricated bathroom series INDIVIDUAL
A variant of the new INDIVIDUAL prefabricated bathroom series will be presented at all important trade exhibitions (SHK-Essen, IFH / INTHERM Nuremberg and GET-Nord-Hamburg).
On 8 December 2017 , senior partner Emil Grumbach died at the age of 84.
His wife Hedwig Grumbach took over his company shares as his successor.
Eccentric Drain und Attic Power Drain
Eccentric Drain und Attic Power Drain are the interesting product innovations from the roof drainage sector.

SLIM-BLOCK
is the name of the company’s new major product innovation. With its 20 cm width, the SLIM-BLOCK is considered the narrowest wall-mounted WC element on the market. In conjunction with the matching angle elements, it is the ideal solution for narrow “hose bathrooms”.
75 years of GRUMBACH
On August 1st, 2013 the company celebrated its 75th anniversary with an “Open House”.
Change in the company management
In 2011, Susanne Konstantinidis, a graduate in business administration, was appointed to the management as the successor to Emil Grumbach.
After 39 years, the Emil Grumbach era as managing director came to an end. The third generation completely took over the management.
New product line Shower Floor Systems
The first GRUMBACH shower floor system (shower floor element + adjustment support element) for the installation of floor-level showers was presented with great success at the international ISH trade fair in Frankfurt.
Third generation takes responibility
In 2004 the decision was made that the company should remain family-owned in the future. Emil Grumbach’s four daughters (Rita Günther, Susanne Konstantinidis, Stephanie Godow and Julia Lengfeld) became partners. Business school graduate Lazaros Konstantinidis was appointed as the second managing director alongside Emil Grumbach.
A corner pre-wall installation is introduced
In 1998, the first two corner WC elements were introduced with great success as “space-saving wonders” for pre-wall installation in bathroom corners.
The first corner WC pre-wall elements are called:
- Corner WC block 108 cm high
- Corner WC block 83 cm high
The company founder died on June 2nd, 1996 at the age of 84.
A new generation of pre-wall installations is born
PUR sanitary mounting blocks (sanitary blocks) were presented for the first time at the IFH ’94 in Nuremberg and these made possible a new and simple method of pre-wall installation. The first two sanitary mounting blocks (sanitary blocks) were:
- the Universal Block 108 cm high and
- the Universal Block 83 cm high.
The first prefabricated shower, the first prefabricated bathroom and the first roof drain
In 1975 the first prefabricated bathrooms, prefabricated showers and roof drains are in serial production and being marketed. As regards flat roof drainage the company offers the widest range of roof drains in Europe.
The second generation takes over the leadership of the enterprise
In 1972 Karl Grumbach handed over the entire management to his son Emil Grumbach. Emil Grumbach joined the company as an apprentice in 1947 and took over the technical management of the company in 1954. Emil Grumbach kept working on new problem solutions for practice. In the course of his life he was able to register a total of more than 30 utility models and 13 patents. The most important developments by Emil Grumbach include
- 1950: Folding bench for hand and foot operation by one person (Today in use almost everywhere.)
- 1960: Electrical screw stock for thread cutting (This solution is also in wide-spread use by installers.)
- 1960: Prefabricated Pre-Wall Installations
- 1961: Adjustable screw fitting for installation elements
- 1961: Visible and concealed cisterns
- 1964: Coverings for installations
- 1965: Development of installation or room units
- 1966: Development of outflows for showers, roof and balcony
- 1968: Development of floor-level shower trays (belong today to the standard range of any shower tray manufacturer)
- 1972: Development of sanitary cubicles, prefabricated bathrooms and prefabricated showers
- 1981: Pipe connections and attachments
- 1982: Development of incubators
- 1992: Development of sanitary mounting blocks for pre-wall installation in PUR
The workshop becomes an idustrial enterprise
During the 1950s GRUMBACH was already devising and putting into effect solutions to problems arising in the workplace, but primarily for its own use. However it was quickly recognised that these solutions might also be of interest to people in other workshops. Since 1965 they have manufactured and sold installation elements or sanitary prefabrications and drainage units for roofs and balconies.
Foundation by Karl Grumbach
On August 1, 1938, the 26-year-old plumber and installation master Karl Grumbach founded his workshop for plumbing, heating and plumbing in Wetzlar – Münchholzhausen.