Historie SONNTAG Baugesellschaft

Bauunternehmen SONNTAG

Our company


Development of SONNTAG


Company founded by Kastor Sonntag with the focus on structural engineering.


Josef Sonntag manages the enterprise, increasingly concentrating on underground construction, road construction and civil engineering.


Creation of a branch in Bingen.


Moves into own premises in the Bingen-Kempten industrial estate; the site is approx. 12,000 m².


First construction site using electronically-controlled pipe driving.


Relocation of the main headquarters from Gondershausen to Dörth industrial estate. The site is approx. 21,000 m². The paved areas are used as a building yard, workshop and storage area.


Entry into the RKS Kies- und Splittwerke (gravel and stone works), Eckelsheim.


Environmental protection prize for environmentally-conscious corporate management.


Founding of the SONNTAG Bau GmbH in Hönow, Berlin.


The executive shareholders, Bernd Sonntag (Dipl.-Ing. (graduate engineer), Dipl-Wirtsch.-Ing (graduate business engineer)) and Marion Sonntag (Dipl.-Ing. (graduate engineer)) manage the SONNTAG Group.


SONNTAG takes over the reinforced and precast, prestressed concrete plant in Halsenbach and starts trading under the name of W + S MONNERJAHN GmbH.


World première in Worms! A 464 m long culvert pipeline is driven through under the Rhine using the newly developed Direct Pipe® method for the first time.


SONNTAG invests in a drilling rig of its own, a BG 20 with 70 t operating weight, thereby gaining a foothold in foundation construction.


Acquisition of another drilling rig with 85 t operating weight.
National and international award for the construction of a trenchless air cushion inverted syphon under the river Enz and the river Nagold. The order was placed by 'Stadtentwässerung Pforzheim' (ESP - 'waste water authority').


The new workshop hall at our headquarters in Dörth is completed. The 1,500 m² hall with state-of-the-art warehousing technology will once again optimise maintenance and project preparation for pipe jacking.


The year of the culvert

In 2015, SONNTAG implemented two enormous long-distance pipe-jacking sections under the Rhine in Cologne and Bingen.


The SONNTAG quality and environmental management system was successfully certified by the TÜV in accordance with DIN ISO 9001 and ISO 14001.


Bingen site - offices given a new lease of life

The tired old premises have been gutted, redeveloped and extended. 240 square metres of new office space: more offices with more room, a larger meeting room with state-of-the-art technology, and an additional archive. Even the entrance area has been completely redesigned.


Acquisition of a new RG 16 T ram and extension of our microtunnelling division with the purchase of a new AVND 2000 AB drilling head and a C50 control container.


SONNTAG invests in two new drilling rigs, BG 20 and BG 28, to expand the foundation construction division.


Purchase of an additional large diameter rotary drilling rig LB 36. This investment will help us to further strengthen our specialised civil engineering division and it was directly used on our XL construction site in Essen fort he Wolfsbachtal collector.


Mega project in Mannheim – For MVV Energie AG we successfully built a Rhine culvert with an outer diameter of 4.10 m using the microtunnelling method.


In silent mourning and full of gratitude we said goodbye to our senior boss Josef Sonntag who died in February 2019. With foresight and courage he directed the SONNTAG Group from 1959 to 1996 and his enthusiasm helped to establish our good reputation as an innovative construction company.

It was with great sadness that we also had to say goodbye to our much-loved senior boss, Trudi Sonntag, in September. Together with her husband Josef Sonntag, she had invested decades into building up the SONNTAG Group with a great deal of hard work, foresight, dedication and tolerance. She was a fantastic lady and a unique character, passionately committed to her family and the company.

 Both of them will remain forever in our hearts.

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