✅ Finnish wood, responsibly manufactured in Lempäälä
✅ Completely natural and safe product
✅ Light and fresh appearance
✅ Excellent resistance to moisture fluctuations
✅ PEFC-certified

Our product uses spruce, a domestic, versatile, and strong softwood that handles moisture changes well. Easy to work with and finish, spruce is ideal for interior use, saunas, and, when treated, exterior cladding. Its warm light color and straight-grained pattern make spruce an aesthetically pleasing choice for visible surfaces. Our PEFC-certified spruce products are responsibly produced and environmentally friendly.

Product information

Product measurements

Product features

Sustainability

Grading rules

You can download the grading rules applied in the manufacture of this product here: Spruce

Minimum order size

Please note that we deliver our products in bundles. Bundle size is indicated together with stock information on top right corner.

Surface treatment brings out the best in wood

The right surface treatment finishes the wood for exactly the purpose it's meant for. It protects the wood, extends its life cycle and gives it a color that suits the look of your home or building.

Not all wood needs treatment, but surface treatment lets you highlight different qualities of the wood. When the wood is treated during manufacturing, it's ready to install right away. This makes tight construction and renovation schedules easier to manage.

Why choose industrial surface treatment?

We paint and treat the wood on our own industrial paintline right after planing. At that point, the wood surface is open and the paint or treatment soaks in effectively. The temperature and humidity on our paintline stay constant, so the paint spreads evenly and dries properly. The result lasts longer than paint applied on site at the mercy of the weather.

• You save time. Industrially treated wood is ready to install, so there's no need to wait for good painting weather on site.
• You get an even finish. In controlled conditions, every board and panel receives the same treatment.
• The wood is protected during construction. The surface treatment protects the wood from rain and sunlight from the moment it's installed.

Surface treatment options

The right surface treatment depends on how the wood will be used and the look you're after.

• Opaque paint covers the grain of the wood and gives the surface an even, finished color. Outdoors, opaque paint protects the wood for a long time.
• Semi-transparent treatment gives the wood a color tone while letting its natural grain show through.
• Sauna protection treatment helps wooden sauna surfaces withstand high temperatures and humidity. It also makes the surface easier to keep clean.
• Fire-retardant treatment gives the wood surface a fire classification of B-s1, d0. This is the highest class available for wood construction products, so fire-retardant wood can also be used in buildings with strict fire safety requirements.

Good to know about wood species

Wood species differ from one another, and the need for treatment depends on both the species and how the wood is used.

• Spruce always needs a protective surface treatment outdoors. Spruce cladding is painted with either semi-transparent or opaque paint.
• Douglas fir and larch are naturally rot-resistant and dense, so they don't need surface treatment outdoors. Left untreated, they turn a beautiful silvery gray over time.
• Thermally modified wood has excellent dimensional stability thanks to thermal modification.
• For wood used in saunas, we recommend sauna protection treatment regardless of the species.

Responsibly treated

We use water-based paints and treatments from well-known manufacturers. Water-based products contain fewer solvents than solvent-based ones, so they put less strain on the environment and indoor air.

DID YOU KNOW? Because we want to operate as sustainably as possible, each batch we treat must be at least 500 meters. This way, we don't waste raw materials, and our operations stay efficient.

Ask us more

We have long experience in wood surface treatment, and we're happy to help you find the right treatment for your project. Contact our sales team to learn more about the options.

Installation

Spruce cladding is painted with either semi-transparent or opaque paint. Ideally, paint the boards before installation. This protects them from the weather throughout construction and lets you paint the areas you can't reach once the boards are in place.

Before installation

Check the moisture content. Wood shrinks as it dries, so the moisture content of the cladding boards must be below 20% at the time of installation. When painting, the moisture content may be no more than 15–18%, depending on the type of paint.

Choose either vertical or horizontal cladding. A façade looks calm and balanced when each wall is clad in one direction only. Combining vertical and horizontal cladding usually calls for a lot of trim and tricky details. Choose a solution that suits the building and its surroundings, and keep the overall look simple and clean.

Painting

Semi-transparent or opaque?

• Semi-transparent paint lets the grain of the wood show through and gives the façade a natural look. A semi-transparent finish needs maintenance painting more often than an opaque one.
• Opaque paint covers the grain and protects the wood for longer. It's a good choice when you want an even color and longer maintenance intervals.

Paint before installation

1. Prime the boards on all sides and ends. You can also use industrially primed boards.
2. Apply the first topcoat before installation. This protects the cladding during construction.
3. Apply the final topcoat within 18 months of installation, following the paint manufacturer's instructions.

Paint cut ends right away

Paint every sawn or cut end as you install the boards. Water soaks easily into the wood through an untreated end.

Paint in the right conditions

Paint when the air, wood surface and paint are all above +5 °C and the relative humidity is below 80%. The best painting weather is warm and overcast.

Maintain the paint finish regularly

Check the façade once a year and repaint it when the finish starts to wear. South- and west-facing walls in particular are exposed to harsh weather.

How to make your cladding last

• Use cladding boards that are thick enough. We recommend a thickness of 28 mm.
• Avoid joints, or use end-matched boards.
• Shape the bottom edge of the cladding into a drip edge so that water runs off the structure.
• Leave a ventilation gap of about 22–25 mm behind the cladding, open all the way from bottom to top.
• Design the plinth so that the bottom edge of the cladding is at least 300 mm above ground level.
• Make sure the window flashings and trim or cladding direct water away from the wall.
• Make sure the gutters and downspouts work properly.
• Make the eaves at least 300 mm wide, preferably 600 mm.

Good to know: Our cladding boards contain heartwood, and the profile determines which way round they are installed. This means that in some boards the heart side faces out, and in others it faces in. Boards containing heartwood may develop small cracks over time. This is a natural characteristic of wood and does not affect the durability of the cladding.

Fastening

Battens

• Horizontal cladding: Install the battens vertically and fasten them securely through the wind barrier to the studs of the exterior wall.
• Vertical cladding: Install the battens horizontally and fasten them securely to the studs through the spacer battens and the wind barrier. The spacer battens let air circulate in the ventilation gap.

Fastening the cladding boards

You can fasten the cladding boards with nails, staples or screws. Whichever method you choose, space the fastening points about 600 mm apart.

The fastening method depends on the board's tongue:

• Full tongue-and-groove boards can be fastened through the tongue. This keeps the fasteners hidden and leaves the paint finish intact.
• Half-tongue boards must always be fastened through the face. This keeps the board from lifting off the tongue as it dries.

Paint over face-fastened points. If you fasten the boards through the face with nails or screws, paint over the fastening points when you apply the final topcoat. This keeps water from soaking into the wood around the fasteners.

With nails

1. Use hot-dip galvanized ring-shank nails at least 75 mm long.
2. Fasten the board at each fastening point with two nails, about 20–25 mm from the edge of the board.

With staples

Staples are suitable for full tongue-and-groove boards only.

1. Use stainless steel staples.
2. Fasten the staples through the tongue of the board.
3. Choose a staple length where the part that goes into the batten is at least twice as long as the part that passes through the cladding board.

With screws

1. Use countersunk screws made of A2 stainless steel.
2. Choose the screw size according to the board thickness. For our recommended 28 mm cladding board, a 5 x 70 mm screw is a good fit.
3. Pre-drill the screw holes, especially at the ends of the boards. This keeps the boards from cracking.

If you use a pneumatic nailer

Use a nailer designed for exterior cladding and hot-dip halfhead nails. With a nailer, you can adjust the nailing depth as you work. Make sure the nails don't sink in too deep and break the wood surface. The nail head should sit flush with the surface, as a recessed head lets rainwater soak into the wood.

Surface treatment of exterior cladding

Spruce cladding needs a protective paint finish. Ideally, paint the boards before installation, or as soon as possible after installation. Apply the final topcoat within 18 months of installation.

You can also use industrially primed boards. The primer protects the cladding from rain and sunlight during construction and speeds up the work, as you can move straight on to the topcoat once the boards are installed. When you buy the boards, check which topcoats are compatible with the primer.

You'll find more information on painting in the Finnish RT building information files and in paint manufacturers' product data sheets.

Maintenance painting

When the façade is repainted correctly and at the right time, wooden cladding lasts for decades. Moisture is the biggest threat to wood, so an intact paint finish is the cladding's most important protection.

When is it time to repaint?

Check the façade once a year. It's time for maintenance painting when the paint starts to fade, chalk or flake. The maintenance interval depends on factors such as the type of paint, weather exposure and which way the wall faces. South- and west-facing walls usually wear the fastest.

• Opaque paint: A carefully painted façade typically needs repainting every 10–20 years.
• Semi-transparent paint: A semi-transparent finish needs maintenance much more often than an opaque one.

Prepare the surface carefully

1. Protect surfaces you are not treating, such as windows. Plastic sheeting works well for this.
2. Remove any loose or poorly adhering paint with a scraper or wire brush.
3. Wash the façade with a mold remover. Washing kills mold and other growth and roughens the old paint surface, which helps the new paint adhere. Thorough cleaning also keeps mold from growing through the new paint.
4. Let the wall dry thoroughly. The moisture content of the wood must be below 20% when you paint.
5. Treat any bare wood with wood preservative and primer before applying the topcoat.

Paint

1. First apply topcoat to the primed repair areas.
2. Then paint the entire façade.

Follow the paint manufacturer's instructions and use a topcoat that is compatible with the primer.

Choose the right weather

• The best weather is a dry, overcast day after a few sunny days that have dried out the wood. The drier the wood, the better the paint soaks in and adheres.
• The ideal temperature is about +15–20 °C with a relative humidity of about 50%. The temperature must be at least +5 °C and the relative humidity no more than 80%, both while you paint and while the paint dries.
• Avoid direct sunlight. The surface you paint must not be too hot. Plan your work so that the sun doesn't move onto a freshly painted wall.
• Watch out for dew and rain. Start painting only once the morning dew has dried, and stop well before the evening dew settles. Don't paint if rain is forecast.

Wood, when used correctly, is a long-lasting and functional exterior cladding material. For facades, spruce, pine heartwood, Douglas fir, heat-treated spruce, or pine are recommended. Our exterior cladding products are made from either spruce or Douglas fir. Douglas fir is a durable material for both exterior and interior use.

Proper and timely maintenance painting is essential for the long-term durability of wooden exterior cladding, except for Douglas fir, which does not require surface treatment. Douglas fir’s advantage is its low maintenance—while it has a higher purchase price as a premium raw material, its life-cycle cost is lower compared to painted spruce cladding, as it does not require repainting.

Using factory-primed (PM) exterior cladding boards reduces on-site costs and saves time. Primer protects the boards from rain and sunlight during installation and speeds up painting work, allowing direct topcoating after installation.

Fine-Sawn Boards

Fine-sawn timber is typically dry-sawn with a band saw. Its rough surface provides an excellent grip for paint, resulting in a durable finish. Dry-sawn wood has a shorter fiber surface than green-sawn timber. Boards may be fine-sawn on one or multiple sides, and are suitable, for example, as corner or fascia boards.

Exterior Cladding Panels

For facade cladding, Douglas fir or spruce (grade AB) is recommended. Spruce has a cell structure that “closes” when dry, making its surface similar from sapwood to heartwood, like pine heartwood. Pine sapwood remains “open,” and only its heartwood is closed. Because of its structure, spruce absorbs less moisture and swells less than pine, making it slightly better suited for facade use.

Slanted Battens (Lattice Slats)

Slanted battens, or lattice slats, are mainly used as privacy screens for terraces, carports, and garden structures. They can be used to create stylish fences, railings, canopies, and decorative structures, adding both privacy and comfort to outdoor spaces. Coverage depends on installation spacing, and battens can also add decorative detail to building facades.

The profile of slanted battens is carefully designed for easy cleaning. The upper slope is installed so water runs off, reducing debris buildup. They can be installed at two different angles.

Glulam Posts

These laminated posts are weather-resistant. Their cut ends should be protected—e.g., with post caps or a handrail—to prevent excessive water absorption, especially on exposed decks or piers.

Durability

Douglas fir is durable and requires no surface treatment. When exposed to the weather, it naturally turns grey; this can be accelerated within a few weeks using ferrous sulfate.

Other weather-exposed surfaces not made from Douglas fir require treatment, as they absorb moisture and may develop mold. Fine-sawn surfaces are excellent for painting due to their rough texture, which ensures strong adhesion. Common uses include fences, canopies, and corner or fascia boards.

Lauta.fi delivers product sample pieces to both consumer customers and professionals, such as architects, interior architects and designers, construction industry and procurement professionals.

If you are interested in ordering one or more sample pieces, please contact our sales department via email lauta@lauta.fi or phone +358 3 3123 6000 (On weekdays 8-16).