In describing the winning entrant the award judges praised the design for its ambition and craftsmanship commenting “visually, the ceiling has a unified feel due to the uncompromising finishing and uniform surface treatment” (Wood Award, Puuinfo). They also acknowledged the calming effect of wood and its use as a building material in the hectic environment of an airport.
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A challenging construction in wood
Manufactured by Raision Puusepät Oy, a total of 7700 m² of wood was used in the roof of the departure hall, the outside box and around the skylight of the terminal. The wavy shape of the roof is made of thousands of curved wooden elements and was one of the most challenging assignments for Raisio Puusepi.
“We started planning the project at an early stage and also made additional investments such as a new CNC milling machine,” said Jari Saarinen, Raisio’s joinery production manager.
“The production of the elements started about a year before the opening of the terminal. The first element was lifted into place in August 2021. All in all, we have prepared more than 10,000 different parts for this object,” Saarinen continued.
Consistent quality in wooden materials and coatings for thousands of parts
All the elements were made in Raisio’s own joinery manufacturing premises, with the largest pieces being over 6 meters in length and weighing up to 1200 kilos.
The shape of the wooden roof is made of multi-layer wooden boards, the most visible surface of which is low-branched spruce. The wooden boards are supported by a hidden pine frame, which is in turn attached to the steel structures. The wooden boards are coated in Teknos water-based, tinted AQUATOP 2600-90 varnish.
“We use an airmix automatic spraying line and the surface treatment went through without any problems. I am satisfied with Teknos’ customer service and technical support, because even though we used about 13,000 liters of paint, the product and tinting were always of uniform quality,” emphasizes Saarinen.
Based on the drawings made by the architect, data models were made of all the parts of the roof, which could be fed to a CNC machine that reads 3D files. The completed parts were finished by puttying and milling edge rounds before surface treatment.
Two coats were applied by automatic sprayer with some smaller parts being sprayed by hand. The finished elements were packed for transport in plastic that protects against the sun’s UV radiation.
“Only after the roof was installed were we able to see the result of our work in the right environment with its uniform look. Our belief is that the product we manufacture must last at least as long as the life cycle goals set for it,” sums up Saarinen.
High environmental consideration
The project was constructed in accordance with the BREEAM (Building Research Establishment Environmental Assessment Method) Excellent environmental rating which looks at the ecology of buildings, including a requirement for very low VOC emissions in surface treatment products. Other requirements from the project team included high quality structures, a flawless finish, easy maintenance and extended life cycle.