The Swedish Theatre in Helsinki, Finland took the decision to seal all of its ventilation ducts and the solution that was adopted was FuranFlex. The total duct length was about 1 km in a project that was faced with special challenges.
Ventia Oy delivered the project using FuranFlex and the Ventia Group installation company was responsible for the duct sealing along with a subcontractor. The work was completed in 2011 having lasted about a year. Henrik Petterson from the Ventia Group has this to say about the project:
– The ducts were vertical and horizontal. They consisted of brick, stone and concrete with duct dimensions ranging from ø80 mm to ø750 mm. The shape varied between triangular, square and round, depending on the space for the ventilation ducts in the walls and floors. FuranFlex was the natural solution and met all of the requirements set by the customer.
The shafts were preserved
The relining with FuranFlex was a part of the whole. The Swedish Theatre was completely renovated, both indoors and outdoors. Electricity cables were re-run and the stage refurbished. The ventilation system underwent a major upgrade.
– The whole building now enjoys a well-functioning supply and exhaust ventilation system which meets sealing class D. The original shafts did not need to be removed, says Henrik Petterson.
Innovative and special structures
Special boxes were constructed which were used to connect the FuranFlex pipes to the ventilation machines and to connect multiple ventilation ducts to a FuranFlex pipe.
– To avoid noise and vibrations in the shafts, we sealed all the gaps between the brick surfaces and the FuranFlex pipes using non-flammable polyurethane, says Henrik Petterson.
Photographing, filming and pressure testing
– All ducts have been photographed, filmed and pressure tested, both before and after the relining. Hole plans were sketched in pencil and assessed by the state run National Board of Antiquities. If the hole is not approved, we need to plan another hole or make a branch.
– The project at the Swedish Theatre put special demands on us as a supplier. An impressive work effort together with the unique characteristics of FuranFlex has meant that we can look back on a successful project, Henrik Petterson concludes.