• Kerto® LVL

    Kerto® LVL laminated veneer lumber
  • Birch plywood

  • Spruce plywood

  • Nordic premium timber

    Nordic premium timber
  • Finnjoist i-beam

    Finnjoist i-beam
  • UK specific products

    UK specific products

Kerto® Sonans

Kerto® Sonans

Kerto® Sonans – Sound absorbing LVL panel

Sonans panels do not only have a warm and modern feel, they also perform well when it comes to acoustic achievement. They control reverberation time and flutter echoes are strongly limited. The optimal sound-absorbing ability of this acoustic panel is achieved by the use of selected and compressed veneers, accurate holes and by using a suitable structure behind it. The perforated product is applied as wall and ceiling panels in sports and gym halls, offices, schools, swimming pools and concert halls. The tests done in several halls show that these panels meet the Olympic Committee requirements. ​


Sonans panels are made of compressed Spruce Kerto veneers and are approx. 20mm thick. The Ø 10 # 20mm perforations are a characteristic feature. 

As a standard, Sonans is delivered with a chamfered edge all the way round. Applying a black (or coloured) non-woven acoustic fleece on the rear is optional. The panels can also be finished in the factory with a transparent or coloured lacquer, which creates a very smooth surface. Thus savings on labour are realised at the construction site. The panels retain their colour and are easy to maintain ​

Sonans is often applied as horizontal or vertical wall panels. They are also used as an acoustic ceiling finishing, for example under Kerto-Ripa roof elements. 

There is a large choice of sizes within 2.500x12.000mm. The standard is 2400/2600 * 595/1200mm. 

Fire resistant properties and other perforation patterns are optional. Examples of the detailing can be found on www.metsawood.com/nl. 


Kerto is primarily manufactured for application in the building industry. If you want to get a feeling for the appearance and quality you can always ask for the quality description or completed reference projects. 


  • Good acoustic absorption 
  • High impact resistance 
  • Regulates air humidity 
  • Natural and warm radiance 
  • Widths up to 2.50m and lengths up to 12m
  • Great shape consistency and high dimensional stability 
  • Sustainably manufactured (PEFC) ​


Laboratory tested for an optimal performance of the elements. The values stated below are based on research by Müller-BBM and serve as an indication. Measurements were made on the basis of DIN EN 20354 and the results have been given on the basis of ISO 11654. The full research results can be requested from Metsä Wood. It is recommended to consult an acoustic engineering agency per project for independent advice on the requirements and wishes and which assembly would perform the best. 

Kerto-Ripa Sonans acoustic roofing elements​

Kerto LVL Sonans - acoustic wood elements
Kerto-Ripa Sonans roofing elements are used to span large open spaces in new buildings as well as renovation projects. Swimming pools, theatres, schools, halls, offices and other commercial or public buildings are spanned this way. For each project, these wooden hollow-core units are customized to the demands of the customer, architect, structural engineer and building contractor. The perforated underside improves the acoustic comfort in the room and provides a warm and pure aesthetic.​

Kerto-Ripa Sonans consists of Kerto joists and one Kerto cover plate which are glued together ​constructively providing a very stiff unit. This certified gluing technique makes very large spans possible (up to 20 meters). On the underside, a perforated Kerto bottom plate has been attached with acoustic insulation behind it. ​

This system can combine multiple functions: 

  • Sound absorption 
  • Vibration-free structural frame 
  •  Stability disc 
  •  Airtightness 
  • Thermal insulation
  • Fire-resistant 
  • Direct final finish ​


Kerto-Ripa elements have a standard width of 2400 mm. The length depends on the substructure and can be supplied up to 20m. ​

The perforated Kerto underside has an standard perforation of Ø 10 on a grid of 20x20mm2 and is built-up of segments of 2400x595mm. Other measurements, perforations or even slots are possible. Each panel is delivered with a chamfered edge all the way round. 

The reverse side is equipped with a black or coloured frame retardant fabric and behind this an acoustic insulation of 50mm. The panels can be lacquered by machine with a transparent and colour layer, which provides for a very smooth surface. This allows for panels to maintain their colour and they are easy to maintain. At the construction site there is no need for a work platform, because the perforated panel is the final finish. 

Fire retardant coatings (B- SI, dC) are optional. 

The perforated underside consists of pine wood veneer. The rustic, industrial DNA is reflected in the surface. If you want to get a feeling for the appearance, just ask us for quality descriptions or completed reference projects.


Kerto-Ripa can be applied by using a basic construction of wood, masonry, concrete or steel.

It is a result of controlled prefabrication, uniform quality and fast and easy construction.

Given the large measurements of the elements, a large surface can be covered quickly: up to 1000 m2 a day. 

The Kerto-Ripa elements are at least five times lighter than concrete hollow-core units. Therefore the structural frame can be less heavy. 

The length and performances can be fine-tuned to the demands and requirements of the customer, architect, structural engineer and building contractor. 


The perforations in the underside allow for the realization of a sound absorption coefficient of 0,75 (Class C). The exact absorption curve depends on the chosen design.


Large bridge spans can be achieved using Kerto-Ripa roofing elements with a small height and a relatively light construction. More height advantage can be realized by placing installations between and through the joists. Panels can also be placed on the load-bearing beam whereby the forces are transferred purely via the top plate. In the table below you can easily read off which height you get given a specific span.

Applications for Kerto® LVL

References related to Kerto®​ LVL

  • FMO Tapiola – wooden office building

  • One Main office

  • Hurlingham Racquet Centre

  • Viikki wooden apartment buildings

  • DB Schenker wooden terminal building

  • ASSYX concrete block shuttering

  • Mega Market commercial building

  • Metsätapiola - wooden office building

  • Aylesbury Waterside Theatre

  • Tommi Mäkinen Racing building

  • My Green World exhibition centre

  • Edinburgh Centre for Carbon Innovation

  • Metropol Parasol - one of the world’s largest wooden buildings

  • Kannustalo ready-to-move houses

  • Endurance Doors

  • Balteschwiler timber merchant

  • Karisma shopping centre

  • Diesel Benelux headquarters

  • Agricultural building, Koski Manor

  • Ämmässuo construction-waste handling plant

  • Kerteminde children’s home

  • Paris police department - wooden extension

  • Immanuel Kirche - wooden structure that impresses

  • Straagaarden using nature's own resources

  • Cinema De Roma – thoroughly renovated

  • Kaifu-bad – oldest spa in Hamburg

  • Schlagwerk – hall for producing musical instruments

  • Berlin-Britz – open air stage

  • Le Pavillion wooden office building

  • De Karel Doorman – 16 floors extension

  • Rakuunantie extension storey

  • Cockfield Windmill – conversion to accommodation using Kerto® LVL

  • Extension to a building in Paris

  • Clamart Sport Centre

  • Östermalm’s temporary market hall

  • SI-modular wood framing system

  • Dome of Visions 3.0

  • School centre dining hall in Schwäbisch Gmünd

  • Pro Nemus visitor centre

  • Kokoon modular housing

  • SPA-Bungalow

  • Center Parcs Waterside Lodges

  • Prefabricated elements by Blueprint Robotics

  • ClipHut construction system

  • Metsä Wood Pärnu Mill

  • Mjösa Tower

  • Hotel restaurant de KASerne

  • Indoor swimming pool at Sport Centre Cents

  • Riding hall in Belgium

  • Verksbyen – sustainable neighbourhood

  • Metsä Pavilion

  • Building D(emountable)

  • A shelter at Nemus Futurum

  • The Macallan Distillery

  • Linnanfältti residential buildings

  • Elementit-E modular wood construction

  • Seagram Building redesigned

  • Aarch - Århus School of Architecture

  • Domaine de l'Hortus

  • Dutch Stay Okay hostel

  • Cranleigh School