WISA PLYWOOD
Story | 04/30/2025 09:54:29 | 6 min Read time

WISA®-Kate Plus protects art lovers at Art Center Salmela’s festival pavilion

Anu Ritvanen

Editor, Tulus

WISA®-Kate Plus (also known as WISA®-Roof) reinforces Art Center Salmela’s pillar-beam festival pavilion. Both the client and the builder have only positive experiences with the underlay plywood, suitable for varying weather conditions.

Next summer, Art Center Salmela, Finland's largest visual arts festival, will enjoy a new festival pavilion that will provide food for the mind and body in the midst of a diverse cultural offering. The summery canopy with a plywood structure and glazing will protect visitors from both sunshine and rain.

Tuomas Hoikkala, Executive Director of Art Center Salmela, has worked as an entrepreneur in the cultural landscapes of Salmela for more than 36 years. He has long experience in construction and renovation projects, as the building stock in the area extends all the way back to the 19th century. The newest building is the festival pavilion, which will be completed by the summer of 2025.

"Architecturally, the pavilion is light, although it has a considerable roof area, like the park stage. Glazing provides additional protection without obscuring the scenery,” Hoikkala describes the 250-square-meter pavilion.

The buildings have something else in common: UPM WISA-Kate Plus plywood has been used as the underlay for both roofs.

Utin Rakennus Oy entrepreneur Arto Nurminen, who is responsible for the construction of the pavilion, knows the material well from other sites.

"WISA-Kate Plus is an excellent, load-bearing underlay material: tongued and grooved, treated with wood preservative, and quick to install," Nurminen says.

 
 

WISA-Kate Plus enhances structural rigidity without additional support

According to Nurminen, the festival pavilion has a pillar-beam structure, so underlay plywood plays an essential role in stiffening the structure without additional support. WISA-Kate Plus is tongued and grooved on the long sides, which makes the underlay a very flat surface for both bitumen felt and sheet metal.

"Tongue and groove machined edges prevent the panels from bending, so the structure remains stable, and the bitumen felt intact, regardless of the season and snow load," Nurminen says.

WISA-Kate Plus is fast to install

Strong yet lightweight WISA-Kate Plus plywood is effortless to work with. The consumption of the standard-sized panels is easy to calculate, so waste is minimal. 26,000 square meters of WISA-Kate Plus have been installed at Utin Rakennus over a period of 10 years, and the entrepreneur has paid attention to the efficiency of the installation. The builders have even made a simple tool from the tongue and groove of the panel to quickly seal the joints.

"WISA-Kate Plus saves on labor costs, as the installation takes about 10 minutes per square meter, compared to almost three quarters of an hour per square meter for tongued and grooved lumber with a sawn face," the entrepreneur says.

Savings are also generated in the fasteners, as they are needed every 300 millimeters in the middle of the structure and only every 150 millimeters on the edges. It is important to remember to leave a small gap on the short edge as specified in the installation instructions.

As an entrepreneur responsible for the safety of employees, Nurminen also appreciates the surface of WISA-Kate Plus: the unsanded surface is not slippery – even in the rain.

 
 

WISA-Kate Plus does not swell

Moisture not only causes slippage, but it can also swell some building materials and permanently reduce dimensional accuracy. Plywood has an inherently high resistance to moisture due to both the properties of spruce and the veneer structure of plywood.

In addition, WISA-Kate Plus is surface-treated with a water-borne wood preservative that prevents moisture penetration into the structure and provides protection during construction against wood staining and decaying fungi. If the plywood is exposed to moisture, it will return to its original size as it dries.

“WISA-Kate Plus does not swell. For example, the OSB solution swells from moisture. With plywood, there is no need to smooth surfaces, repair fastenings or worry about mold spots on exposed structures,” Nurminen points out.

Long user experience for reassurance

WISA-Kate Plus is manufactured at UPM Pellos plywood mills from Finnish spruce. A Declaration of Performance (DoP) , Environmental Product Declaration (EPD) and M1 indoor air emission classification are available for the product.

Both the client and the builder of the festival pavilion appreciate the domesticity and guaranteed quality of the material. The National Board of Antiquities has also approved the WISA-Kate Plus underlay plywood for the protected renovation site of Art Center Salmela. Underlay plywood is also suitable for cold sites, as condensing moisture does not harm ventilated structures.

“In ten years, there has been no concern about WISA plywood at any site. It's always one less worry when you have a familiar and safe product to rely on,” says Hoikkala.

Hoikkala recognizes that technical durability and visual harmony go hand in hand in the construction of cultural sites. The builder, the client and the public benefit when the structure of the pavilion supports its intended use and remains in good condition.

"Construction can be art just as much as the exhibitions themselves, and art and construction are manifestations of love," Hoikkala sums it up, paraphrasing a well-known architect.

 

Art Center Salmela

  • Extensive summer exhibition of Finnish contemporary art, concerts and other cultural events.
  • Located in lake scenery in Mäntyharju.
  • The cultural milieu includes the Salmela carpenter empire-style main building and the 19th-century Domander courtyard.
  • The Festival Pavilion will open in the summer of 2025.
  • Approximately 30,000–40,000 visitors each summer.

Utin Rakennus Oy

  • Builds for the public sector and industry, mainly schools, kindergartens, and ice and sports halls.
  • The family business was founded in 1989.
  • Domiciled in Kouvola.
  • Employs about 20 employees.
 
 
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