Story | 10/31/2023 10:20:57 | 5 min Read time

Sturdy tongue and groove WISA plywood gives builders peace of mind

WISA spruce plywood with tongued and grooved edges is carefully designed for durability. It is the right choice when you are looking for consistent quality, easy installation and sturdy structures.

Tongued and grooved (T&G) plywood offers builders a fast and easy method to install subfloors, roofs and other structural elements with correct alignment and a secure, tight fit. The clever fitting method makes it easy to build sturdy and rigid surfaces with minimum effort.

Globally, edge-machined plywood comes in different qualities and wood species and with highly different technical properties, so the variation between the many products on the market is huge.

Exceptional strength

“Finding a panel with the right profile is not enough. Fit and performance are extremely important, so the design must be thought through,” says Riku Härkönen.

As UPM Plywood’s product manager for spruce plywood, he knows that nothing in the design of T&G WISA spruce plywood has been left to chance. A WISA T&G plywood panel is made up of an odd number of layers of the finest Finnish spruce veneer. The edges are routed in three layers of veneer, with the middle layer going in another direction than the two outer ones. This makes for a strong panel with durable machined edges.

Competing T&G products are typically made of thicker veneers than WISA plywood. The veneer thicknesses and construction used in WISA panels ensure uniform properties in all directions, explains Härkönen. 

“If the T&G edges of a panel are routed in a single layer, the machinings crack easily. By using many layers, the importance of each layer is smaller, giving a more reliable product.”


A roof should stay flat and straight

UPM Plywood’s offering includes several T&G options. Among them are WISA-Roof, WISA-Sprucefloor in the UK, WISA-Kate Plus for the Finnish market, WISA-Wall Ergo in Sweden, as well as numerous other market-specific special products. The standard WISA-Spruce panel is also available with T&G on two or four sides on request.

T&G WISA spruce plywood panels are typically used for sloped roof and floor structures. They are always produced in Finland from Finnish spruce but are sold and shipped to all continents with Antarctica as the only exception.

The WISA plywood T&G design translates directly to benefits for developers and construction workers on-site, making for easier processes and durable buildings.  
“We understand how our customers use our products, and we want to make sure that they succeed every time. Our spruce products are good-looking, have uniform technical properties and are cross-sanded to minimise splitting of the wood fibres,” Härkönen says.

“Thanks to minimal moisture movement, a roof made with tongued and grooved WISA plywood will be flat and straight and stay that way. Lower grade plywood products tend to give warped roofs,” adds Frank Leijendeckers, UPM Plywood’s sales manager in Belgium, the Netherlands and Luxembourg. “Anyone can make plywood, but the devil is in the detail.”

The Benelux countries are UPM Plywood’s biggest spruce market. Based in the Netherlands, Leijendeckers takes care of sales in the region, while Härkönen provides technical expertise and product insights from Finland.

“We’re a dynamic duo, like Batman and Robin,” Leijendeckers notes. Who is Batman and who is Robin varies from case to case, he adds.

WISA T&G panels will always fit

UPM Plywood’s customers in the Benelux countries are happy with the T&G WISA plywood offering.

“We receive no complaints about our T&G products. Instead, builders come back for more and recommend it to others,” notes Leijendeckers. The reason is that they get value for money, he argues.

“If you buy a competing, cheaper product, you might need several people to install the panels and perhaps only nine out of ten products are good enough. A UPM panel that one person can fit and where ten out of ten panels can be used will turn out to be more affordable in the end.”

Leijendeckers highlights that all T&G WISA plywood panels are made on the same edge-machining line at the UPM Pellos plywood mill in Finland. This means that the dimensions are always the same and all T&G WISA panels will fit, no matter when they were purchased.

The panels are always entirely made of 100% traceable Finnish spruce from responsibly managed forests, making it easier to comply with the EUDR requirements. Light to handle yet strong, it is an ideal material for structures.

Commitment, commitment, commitment

During his five-year-long career in UPM Plywood, Leijendeckers has experienced unparalleled commitment from his colleagues at the Pellos mills.  
“Everybody knows the ins and outs, so they can make adjustments in a heartbeat. They have Fingerspitzengefühl (gut feeling). Now the knowledge is being passed down to the next generation,” he rejoices.

The customers notice the commitment not only in the form of an outstanding product but also in the form of engagement, consistent high quality and reliability.

Härkönen, for his part, has worked at UPM Plywood for more than half of his life. During his long career, he has noticed that it takes more than a superior product to be a good plywood supplier.

“Delivery times, accuracy and constant availability are key. What we promise, we keep, also if it takes an extra shift or extra effort.”

Although plywood is only a small part of most building projects, it can mean tremendous costs if the product is not fit for purpose.

“Thanks to our excellent staff at the Pellos mills, our technical figures are always correct, so we can deliver peace of mind,” Product Manager Härkönen concludes.

Text: Sara Steensig 

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