Story | 04/26/2023 06:12:16 | 9 min Read time

How to choose the right plywood product

Plywood is not just plywood. If you are looking for plywood for your building project, you might have noticed that this natural material comes in different wood species, grades and thicknesses and with various surface treatments. This article guides you to find the right WISA product that matches your needs.

Plywood is a versatile material that is used in a host of applications and end-uses. WISA plywood is made of wood raw material from responsibly managed forests, so it is a sustainable and safe material that helps reduce the carbon footprint of construction. 

If you are not sure what plywood products to choose, it makes sense to look at how you are going to use them! This article focuses on what WISA plywood to choose for building and construction, based on the end use. 

Birch or spruce plywood? 

WISA plywood is manufactured from birch (hardwood) and spruce (softwood). To make the choice easier, it is useful to know the characteristics and strengths of each wood species. In construction, birch plywood is ideal for interior design and concrete forming while spruce plywood excels in structural uses, such as floors, walls and roofs. 

Hardwood or softwood? 

Hardwood characteristics 

  • Birch is hardwood 
  • The smooth and light-coloured appearance of birch plywood works well in applications that require visual appeal 
  • Excellent strength and stiffness make it ideal for applications where bending is not allowed even under heavy loads, such as trailer floors and formwork 
  • Due to higher density, the dimensions change more with moisture compared to spruce 

Softwood characteristics 

  • Spruce is softwood 
  • Light but strong spruce plywood is less stiff than birch plywood: it may bend under heavy loads but does not break easily 
  • Spruce plywood is ideal for load-bearing  structures, such as floors, walls and roofs 
  • The closed wood structure of spruce makes it biologically more durable than birch, meaning that it withstands various conditions in construction applications 
  • Due to lower density, the dimensions change less with moisture compared to birch 

WISA spruce plywood for all construction needs 

Plywood is an excellent choice for load-bearing building structures, such as floors, walls and roofs. If this is what you need plywood for, then odds are that a spruce panel will fulfil your needs.  

WISA-Spruce plywood is an all-rounder for building and construction. Light to handle yet strong, it is ideal for structures. With a wide range of panel sizes, WISA-Spruce plywood is quick and easy to install too.  


Spruce plywood panels are mostly used in structures hidden from the eye, meaning that appearance becomes secondary. WISA-Spruce can also be left visible, typically in applications with no special appearance requirements, like garages or storage rooms. It also works when going for a slightly rougher or rustic look. Read more about the various spruce surfaces here or check out the more detailed description of surface grades and the allowed defects in the Spruce surface guide. 

When looking for plywood for construction, it is important to make sure that it has a CE2+ rating as proof of its strength. All WISA plywood products intended for use in construction have the CE2+ marking, meaning that they will perform exactly as specified. 

Check our video and learn how to recognise a structural WISA plywood panel

Strong and lightweight, WISA-Spruce is the perfect material for floor, wall and roof structures. 

Benefits of the strength  

  • Can be used in load-bearing structures 
  • Fixtures can be easily attached to the panel itself, no need to figure out where the wall beams are 
  • WISA plywood complies with the Eurocode 5 standard for structural timber design 
  • Adheres to different relevant national requirements for, e.g., the rigidity of floors, snow loads on roofs or requirements for wall structures. 

Benefits of the light weight  

  • The panels are easy to carry on site
  • A lighter structure puts less strain on the foundations
  • Buildings can be expanded upwards easily
  • Transport costs are lower, a trailer can fit more panels and fuel consumption is reduced. 

Specialised WISA spruce plywood for floors, roofs and other uses 

With different surface treatments and through sizing and machining, UPM’s strong and light WISA-Spruce base panels can be refined into specialised products, while retaining all the good features of the base panel. The added features and functionalities make construction easier and more efficient when dealing with special or demanding projects.  

Plywood made for floors and roofs is, for instance, tongued and grooved and the panel sizes are optimised for quick installation. Surface treatment is another way of optimising plywood for particular applications or end-uses: if your construction must live up to strict fire regulations, choose a fire-retardant spruce panel. There is a WISA-Spruce product for every need - check the fact box below to find the perfect match. 

Specialised WISA spruce plywood panels
treated to fit every builder’s need.

Application Product Description
Floors WISA-Spruce TG4 / WISA-Spruce TG2 / WISA-Sprucefloor (UK)  Engineered half-sized panels designed to fit flooring structures. Tongued and grooved on all four sizes for strong and durable subflooring. Needs a final surface, e.g., parquet, vinyl or laminate.  
Roofs  WISA-Roof Developed for roofing. Biocide-treated with rough, non-slippery surface and tongue and groove on the long sides. Due to panel sizes and machining, the roof is quickly assembled and ready for the main roof material. Bright yellow tone on both surfaces.  
For structures that need fire classification  WISA-SpruceFR  Fire-retardant plywood. The best fire classification a wood product can have. Prolongs the ignition time and reduces the formation of smoke. The treatment extends the rescue time in case of fire. A light-yellow tone on both sides, and the product name is laser-printed on the backside.  
For extra efficiency on site  WISA-SpruceWR  Water-repellent plywood. Slows water absorption into the plywood and still lets it breathe and dry. Saves time on site when you don’t have to worry about covering the plywood for every raindrop.  
For structures requiring high durability   WISA-SpruceBT  Biocide-treated plywood. It protects the plywood from wood-decaying fungi and colouring during construction. A bright yellow tone on both surfaces. 
Visual applications  WISA-Spruce Special  No open defects on the surface. Suitable for applications where the face is left visible, like in shop fitting or DIY, or if the surface will be coated or painted, for instance. 
Various formwork applications  WISA-Form MDO  Ideal for formwork applications where a matt concrete finish is desired. The light spruce panel is easy to handle at the site and cost-efficient to transport. 

WISA birch plywood for interior design and concrete formwork 

Uncoated WISA-Birch plywood is used in interiors and furniture to create a light, warm and visually pleasing look. WISA birch plywood makes beautiful inner walls, cabinets and shelves, among others.  

No plywood panels will look the same. That is the beauty of natural materials. For a polished look, go for a WISA-Birch Premium. It is light and uniform with a face veneer made of one sheet. Check out the different birch surfaces on our website. A more detailed description of surfaces and the allowed defects can be found in the birch surface guide 

WISA-Form birch plywood is a popular material for concrete moulds due to its strength. In demanding formwork and casting applications, film-coated birch plywood is highly durable and can be used for dozens of castings if properly maintained.  

How to choose the right thickness 

No matter what type of WISA plywood you decide to use, you can rely on its performance, so you don't need to buy anything "extra". If a surface will be covered, appearance does not matter. And the same goes for thicknesses: forget about buying an extra thick plywood panel just to be safe. You can trust that WISA plywood will perform as promised. 

Check with your distributor what thicknesses they stock. On the product page, you will find the manufactured standard thicknesses of each product, as well as the panel sizes. Standard sizes and thicknesses, and also weights, are gathered on our dedicated webpage.  

Find the detailed technical performance, like strength, on the DoP Declaration of Performance (DoP) reference list and, for the UK, in the Declaration of Conformity (DoC) documents on the website.  

Plywood for indoor or outdoor use? 

All WISA plywood products, including those with fire-retardant, water-repellent or other treatments, are always M1 certified. The certification is a low-emission classification of building materials, meaning that they are safe to use in permanent structures of homes and other buildings.  

WISA products are biologically durable, especially spruce veneer, and nearly all of them are bonded with weather-resistant glue. Nevertheless, they do not like too much rain. Therefore, we suggest that any part of a building that is left outside, even under a roof, is covered somehow, at least with a suitable paint.  

Text: Sara Steensig

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