Strong. Beautiful. Kerto.

Introduction

Practical materials, iconic results

Whether you are building a new Colosseum, or something slightly less unusual, Metsä Wood Kerto products support practical, aesthetic, and budget-friendly solutions.

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Colosseum

Rock solid connections

Kerto-Q is a load-bearing, bracing and dimensionally stable LVL panel
Product: Kerto-Q

​Kerto-Q is a load-bearing, bracing and dimensionally stable LVL panel used in the most demanding structures. It can be used in Kerto-Ripa elements that enable stiff and high-quality floor and roof structures. The elements can be equipped with holes for HVAC equipment, and the load-bearing capacity is not reduced significantly.

Main beam and column connections
Main beam and column connections

​Inclined tension screw connections are used to join consoles supporting the arch-sharped Kerto-Q floor beams. When load is placed on the connection tension is transferred through the screws and placed directly onto the load-bearing column. The compression force is relayed via direct contact through the console piece to the column, and is further supported by kinetic friction.

 


Kerto-S LVL beams
Product: Kerto-S

​Kerto-S combines excellent technical performance with ease of use. Its essential qualities include strength, dimensional precision and stability. It is the ideal choice for beams whenever long spans are required.

Floor connections
Floor connections

​Floor elements are held in place by large, 10mm timber screws which go through the flooring and anchor to the supporting beams below. The screws are simple and safe to put in place as they go directly into the horizontal floor from above.



 

Kerto-Q
Product: Kerto-Q

​Kerto-Q is a load-bearing, bracing and dimensionally stable LVL panel used in the most demanding structures. It can be used in Kerto-Ripa elements that enable stiff and high-quality floor and roof structures. The elements can be equipped with holes for HVAC equipment, and the load-bearing capacity is not reduced significantly.

Inclined terrace beam connections
Inclined terrace beam connections

​Timber connectors straddle the columns and beams and function as torsional restraint supports for the beams. Lateral screw connections between columns and beams are used to hold terrace beams firmly in place atop the Kerto-S columns.

Metsä Wood solutions throughout

 

Fewer columns, more flexibility: Kerto
Fewer columns, more flexibility: Kerto

​A lighter over-all building mass requires fewer columns to support its weight. The building is more spacious and open – and allows for more flexible and multi-use applications of the facility.

MEtsä Wood Floor - Birch plywood for flooring
Floor: Metsä Wood Floor

Metsä Wood Floor is birch plywood overlaid with multi-layer phenol film with a rough wire mesh pattern. The rough-surfaced Metsä Wood Floor is an heavy-duty, multipurpose plywood flooring panel for applications requiring a reliable, long-lasting anti-slip surface.

Plywood and Kerto for concrete formwork
Concrete formwork: Form Plus

​Metsä Wood has launched a new birch plywood panel for concrete formwork applications featuring an innovative coating that enhances the smoothness of architectural concrete surfaces. Called FormPLUS, a patent-pending coating provides much more resistance to moisture absorption in order to dramatically reduce the ripple and grain marks that conventional plywood panels can leave on visual concrete.

Plywood for concrete formwork - Metsä Wood FormPlus

 

Birch plywood - Metsä Wood Form
Stage: Metsä Wood Form

Metsä Wood Form is birch plywood, in which both sides are overlaid with phenol film and the edges are sealed. Form plywood is the formwork panel of choice for smooth surfaced concrete elements. It can also be used as a multi-purpose, maintenance-free sheathing panel for various other uses.

Suitable plywood for every purpose
Seats and stand floor

​Seats: Metsä Wood Spruce Flex

Metsä Wood Spruce Flex is a coniferous plywood panel overlaid with a coloured UV-resistant thermoplastic overlay. Panel is suitable for non-residential interior and exterior applications such as wall and ceiling panels for agricultural constructions and warehouses.

Read more about Metsä Wood Spruce Flex

Stand floor: Metsä Wood Granit Top

Metsä Wood Granit is birch plywood panel overlaid with special decorative overlay. High visual quality and wear-resistant surface makes Metsä Wood Granit durable, multipurpose plywood flooring panel.

Read more about Metsä Wood Granit Top

Reichstag

Lots of alternatives

Top slab connections allow simple wall elements. Only the top panel is on top of the supporting structure. This allows for a lot of flexure for internal wall design and later flexibility.

Wooden connections - timber-to-timber
Connection: Timber-to-timber

​Timber-to-timber connections are cost effective as they are done directly between two timber pieces. As there are no steel pieces in this connection, it works well in industrial environments, which often have an acid atmosphere.

Wood connection: Timber-to-timber screw
Connection: Timber-to-timber screw

​Using screws in timber-to-timber connection is beneficial as screws can utilize the rope effect very well, which increases the connection lateral load-carrying capacity. When used with Kerto only larger screws generally need pre-drilling. Depending on the screw manufacturer, large drill-bit screws can be used without predrilling, which increases the effectiveness of the connection. Screws can also be installed at an inclined angle, which improves the connection capacity and makes the connection yet stronger. This type of connection is also quite fire resistant as the connectors are largely encased within the wood material.

Wooden connections: Steel-to-timber
Connection: Steel-to-timber

​With multiple shear plane steel-to-timber connections, the steel pieces are usually slotted inside the timber to increase resistance to fire. The steel parts are easy to connect to the surrounding structures. The ductile behaviour of the connection has elastic capacity and this allows for considerable displacement before failure. Avoiding failure is possible in most cases by reducing the stress on the connection.

Chords: Kerto-Q
Chords: Kerto-Q

​Because of its strength, Kerto-Q would be used for the top and bottom chord. Kerto-Q is cross-bonded Kerto, meaning that one fifth of the veneers are glued crosswise. This structure improves the lateral bending strength and stiffness of the panel, thus increasing the shear strength when used as a beam. Due to its cross-bonded structure, Kerto-Q has good cracking resistance that can be utilized in connection design. Kerto-Q provides a functional solution in structural components, particularly when a high shear strength is one of the requirements.

Diagonals: Kerto-S
Diagonals: Kerto-S

​The diagonals would be made from Kerto-S. It combines excellent technical performance with ease of use. Its essential qualities include strength. Dimensional precision and stability. It is the ideal choice for truss members whenever high strength is required.

Whatever the material, there’s a connection

There are a lot of alternatives for Kerto connections. The selected fastener type depends on the structure, material and required visual end result. In the Reichstag dome, for instance, hidden connections would look best.

Wooden structure connection: Aluminium console connectors
Connection: Aluminium console connectors

​Aluminium console connectors made by SHERPA consist of two aluminium parts, which create a form-fitting traditional dovetail connection. Originally, this type of connection came from furniture production. To achieve a high degree of prefabrication and to transfer heavy loads, this connection was revised for timber construction. If required, this connection is not visible after assembly and saves time at the site. The non-visible connection is especially reasonable with increased fire protection requirements. By using crossed, full-threaded screws, screwed below a certain angular connection, they are attached to the wooden parts. Through high-tech timber framing, it is possible to install these connectors custom-fit. Loads of currently up to 500 kN can be transferred in this way. By the outstanding feature of dimensional accuracy of Kerto laminated veneer lumber, the use of aluminium dovetails fits perfectly.

LVL beams: Kerto-S
Beams: Kerto-S

​Horizontal Kerto-S would be used for the beams. Kerto-S is suitable for all roof shapes, also performing well as joists and lintels, in trussed constructions and frames. Kerto-S is also a widely used material in the manufacture of prefabricated components.

Wooden Connections: Timber-to-timber with fully threaded screws
Connection: Timber-to-timber with fully threaded screws

​Until the mid-1960s wood screws were rarely found in the construction of timber structures – and if, only from 12mm or thicker. Around the end of the 1990s, new applications were continuously found and developed. The bolt materials and geometries were perfected afterwards. In this example, a secondary beam is connected to the main beam. Crossed full-threaded screws were used for it. These are screwed in a variety of places (depending on loads) with a screwing angle of 45°. The connection is very flexible and cost-effective. The screws take shearing forces or forces in screw longitudinal axis.

Kerto-Q lvl panels
Columns: Kerto-Q

​Kerto-Q is a load-bearing, bracing and dimensionally stable LVL panel that can be used even in the most demanding structures. It can be used in Kerto-Ripa elements that enable stiff and high-quality floor and roof structures. The elements can be equipped with holes for HVAC equipment, and the load-bearing capacity is not reduced significantly.

Connection: Timber-to-timber with partial thread screws
Connection: Timber-to-timber with partial thread screws

​To connect individual timber components, dowel type fasteners are suitable. One type has already been described in ”Fully threaded screw” connection. A remote form of the full-threaded screw is the partial thread screw. The partial thread screw contracts the individual components by its geometry. The thread doesn´t extend over the entire length of the screw and can thereby record almost exclusively shear forces. With this screw, Kerto-Q panels can be mounted on a substructure. Designed as a static disc, these elements can brace complete buildings such as the Reichstag against e.g. wind forces, as a wall or ceiling element.

Wooden floor: Kerto-Q panels
Floor: Kerto-Q

​Kerto-Q is a load-bearing, bracing and dimensionally stable LVL panel that can be used even in the most demanding structures. It can be used in Kerto-Ripa elements that enable stiff and high-quality floor and roof structures. The elements can be equipped with holes for HVAC equipment, and the load-bearing capacity is not reduced significantly.

Keep it simple – and flexible

Top slab connections allow simple wall elements. Only the top panel is on top of the supporting structure. This allows for a lot of flexure for internal wall design and later flexibility.

Kerto-Ripa roofing element
Roof: Kerto-Ripa roofing

Kerto–Ripa roofing elements are made from Kerto® LVL using structural gluing. The element is used as load-bearing roofing and it enables longer – even 18m – spans with the normal structural height of the roof. Kerto–Ripa roof elements are used in roof structures in residential and public buildings. With Kerto–Ripa roof element the building's roof is ready in one go. The element is delivered to the site with a pre-fabricated ready ceiling surface, thermal insulation and roof covering. The pre-fabrication guarantees the elements' homogeneity and quality. Its erection time is short – in one day up to 1500m2 of weather protection can be installed.

Connection: Kerto-Ripa to load-bearing frame
Connection: Kerto-Ripa to load-bearing frame

​Kerto-Ripa elements can be installed on top of load-bearing frames or walls. This connection is generally used in multi-element systems. This connection, as shown in the one presented above, are fastened to the load-bearing frame from the top of the level – which is safer with regard to the work of the assembly crew.

Connection: Kerto-Q wall panel
Connection: Kerto-Q wall panel

​Self-supporting panel joint. The edge of the panel can be machined for self-supporting panel joists. Usually they form a half-lap connection in which part of the panel thickness is machined to create matching pairs of edges. The connection can be designed to transfer the load parallel to the joint.

Kerto-Q wall pane connection
Wall panel: Kerto-Q

​Large Kerto-Q LVL panels are a popular choice in wall panels because they stabilise the whole structure, and good fire resistance is achieved with a properly chosen thickness. Kerto-Q provides a functional solution in structural components, particularly when high shear strength is one of the requirements. Kerto-Q enables quick and easy design and construction. The elements are easy to connect to each other and other parts of the structure.

Connection: Kerto-Ripa top slab
Connection: Kerto-Ripa top slab

​Kerto-Ripa intermediate floor elements are connected to load-bearing structures through the top panel, which can be installed on top of the load-bearing wall or beam, thus keeping the floor height low. If necessary, an acoustic strip is installed on the contact surface between the panel and the wall. The wall on the next floor can be constructed directly onto the top panel of the Kerto-Ripa element.

Kerto-Ripa floor floor elements
Floor: Kerto-Ripa floor

​Kerto–Ripa® floor elements are used in intermediate and base floor structures in residential and public buildings. The basic structure of the element is lightweight, soundproof and requires no on-site concrete casting. Due to the element's long span buildings require fewer load-bearing columns, beams and structural connections. The elements are light, meaning that they reduce the load on foundations and can be used even if the ground has a very low load-bearing capacity. Kerto-Ripa elements are stronger and stiffer than rectangular beams of equal height.

Product information

More product information on Metsä Wood website