Underwater construction work

Underwater construction requires special expertise. Unwa Oy’s personnel have been involved in several underwater construction projects. A professional diving team is always required to achieve a high-quality result. Another important factor in diving work is ensuring the equipment has been maintained and inspected by the relevant deadlines.

Unwa Oy’s divers have installed prefabricated elements and carried out erosion casting for harbour quays.
We have also carried out various concrete repair jobs at several hydropower plants.

Ordinary concrete repair work includes concrete encasing and die casting. The summer and winter conditions in Finland exert considerable strain on concrete structures underwater and near the waterline. It is important to inspect and repair concrete structures to ensure their longevity.

Underwater construction work always requires careful planning and execution. Safe equipment and personnel guarantee a successful outcome, even on the most challenging projects.



Erosion casting
Die casting
Pressure grouting
Prefabricated element installation
Mortar replacement


Construction and installation of shuttering forms
Construction and installation of die casting forms
Installation of heavy metal
Underwater welding
Underwater flame cutting
Underwater earthmoving and excavation (by airlift pump or ejector)