FOCUS: Timber engineering & wood screws

Timber construction takes many forms and each has its own fastener requirements. We take a look at some of the new products and range extensions hitting the market, to make the job easier and more efficient.

Eurotec > Innovative solutions for timber construction project

Cross Laminated Timber (CLT) construction is on the rise – with particularly advantageous properties, the flexible wood product is creating enormous development in the wood industry. Building with wood has always been an innovative and sustainable way to build complex and modern buildings. In this context, the ecological building material cross-laminated timber (CLT) is becoming more and more successful.

This brings with it many advantages that make building with the renewable raw material special. In this respect, Eurotec would like to make a contribution to strengthening timber construction with CLT and has dealt intensively with fastening and anchoring systems for prefabricated timber elements. In recent years, traditional timber construction has continued to expand and the use of mass timber represents an important enrichment for the industry. CLT is considered to be extremely strong and dimensionally stable and it is primarily used for modern building construction.

The field of application of CLT extends over many areas: complete buildings as well as multi-storey residential buildings can be constructed with it. All components such as walls, ceilings and roofs can be manufactured using just one building material. The advantage here is that cross-laminated timber is soundproof and heat insulating. Large scale projects such as commercial and industrial construction can also be ideally managed with it. CLT is also used in extensive bridge construction. The CLT construction primarily impresses with the short and uncomplicated assembly time of the prefabricated wood elements. With selected fastening and anchoring techniques, Eurotec supplies tailormade system solutions. Complex areas of timber engineering can be consistently covered.

Optimum load distribution and the absorption of tensile and shearing forces are essential for many projects. The company offers a variety of solutions for highly stressed wood connections of all kinds: special system angles, shear angles for wood-wood or wood-concrete connections and tie rods have been specifically designed for applications with CLT and make wood construction work considerably easier. In addition, the company also offers pull tabs to absorb tensile forces. These are suitable for connections on wood as well as on concrete and steel. Thanks to special screw holes, they have proven to be particularly efficient in assembly. With the versatile CLT system angle, for example, complex connections can be created that enable transmission of major forces. Wood connectors of this type not only bring a very effective, but also an economic advantage. Important information about products such as wood connectors and screws as well as technical details can now be found in Eurotec’s detailed CLT brochure.

Due to the growing challenges and the rapid development of the wooden building material CLT, the company wants to give building with wood more importance and shape the industry together with its customers. Eurotec supports the planning and the realisation of projects with innovative products.

The aim is to continue working on unique solutions for system connectors in order to meet future requirements in timber construction.

fischer > FAFS the latest addition to fischer’s range of screws

fischer Power Full and PowerFast screws with full and partial threads are the economic, reliable and quick solution for timber, interior and drywall construction. The fischer chipboard screw PowerFast II can be used for all types of wood on wood and wood on metal connections as well as in fischer plastic plugs with verified loads. The FAFS adjusting screw is the latest addition, offering infinitely adjustable installation of wood structures or frames.

The respective versions of fischer’s full and partial threaded screws (Powerful and PowerFast) are particularly suitable for loadbearing wood structures, reinforcements and renovations, for wooden frame construction, outdoor areas, fastening rooftop insulation systems and much more. The product range provides the right screw type for every application in terms of diameter, length, head type, drive, thread, coating, material strength and other criteria – all with an assessment (ETA). Their clever designs make them easier to install while enabling gap-free and splinter-free fastenings close to the edge.

The PowerFast group includes high performance wood and chipboard screws with a partial thread, which allows them to be screwed in close to the edge without splitting. They are approved for soft and solid wood and are available in a stainless-steel version especially for the outdoors. The PowerFull family specialises in challenging connections and reinforcing loadbearing wood structures. Thanks to their full thread, the wood screws transfer acting forces such as on main and secondary beam connections, false beam edges, shear tension bracings or shear connections. Any wood and steelplate-wood connection can be carried out with the versatile fischer PowerFast and Powerful screws.

fischer’s PowerFast II chipboard screw provides added benefits with its broad range of applications, including any wood on wood or wood on metal connections as well as in fischer’s plastic plugs with verified loads. PowerFast II guarantees good loadbearing capacity and makes installation quicker due to its fast bite and short screw-in time. Short edge distances and axial spacing are also possible without causing the workpiece to split. The PowerFast II’s clever geometry with a specially developed screw tip prevents tears to surfaces.

Countless fastening jobs require standoff installation, such as substructures made of wood used to clad walls and ceilings. The new FAFS adjusting screw with a European Technical Approval (ETA) is ideal for applications such as these. The PowerFast II version enables infinitely adjustable standoff installation.

The FAFS features a clever clip on the head of the screw as well as many other technical ingenuities for this purpose. Its special operating principle makes positioning and aligning fixtures such as substructure battens quicker, simpler and more precise. Any unevenness in the anchor substrate can easily be levelled out and straightened. The unique thread of the PowerFast II screw provides a quick bite and is easy to screw in. The special shape of its clip prevents it from rotating during adjustment so that the screw head retains its flush position in the attachment part without protruding. The FAFS can be disassembled at any time, if required. A thread is located on the outer part of the clip, enabling it to be unscrewed.

The FAFS is suitable for push-through installation and is very user-friendly. Simply place the setting tool onto the bit and screw in the adjusting screw until it sits flush with the surface of the fixture. Then it is ready for the infinite adjustment of the attachment part. The component distance can be infinitely adjusted with the bit without an additional setting tool and by altering the rotational direction. The clip remains in its position in the fixture while doing so.

Predrilling with a diameter of 6 mm is recommended for wood slats with a strength of less than 30 mm when installed close to the edge. The guidelines of ETA19/0175 should be observed for approved applications. The product can be used in masonry with the fischer DuoPower 6x50 or UX 6x50 plugs, which also requires predrilling with a diameter of 6 mm. The current range includes four FAFS variants in measurements of 5x80 mm, 5x90 mm, 5x100 mm and 5x120 mm, each with a TX25 drive. The corresponding setting tool with a suitable bit is also available through fischer.

HECO > HECO-TOPIX-plus now with extended range

HECO helped revolutionise the screw market in August 2020 with the Timber Construction Screw HECO-TOPIX-plus. In the first step, the T-Drive sizes in the diameters 3.5-6 mm were harmonised. In order to provide consumers with the drive sizes they are accustomed to, the Black Forest company has now expanded the range.

“The right drive size is a question of faith in the T-Drive segment,” said Jakob Braun, Product Manager at HECO. “There are many different habits and preferences here, some of which are regional, but some of which are based on personal experience.” To address this challenge, the Black Forest screw specialist has expanded the range and now also offers the HECO-TOPIX-plus as a countersunk screw with milling pockets in the HD25 drive size for diameters 4.5 to 6 mm. The range is rounded off with the Timber Construction Screw TCS in diameter 5 mm with a 60° countersunk head with milling ribs and a HECO-Drive HD30.

“We think from the user’s perspective and offer what the customer demands and is used to. This also gives us the opportunity to address the real advantages of the HECO-TOPIX-plus in customer discussions – such as the MagicClose effect or the HECO-Drive with GripFit.”

The new HECO-Drive concept is based on the well-known T-Drive. The drive in the screw and the slightly conical bit are precisely matched to each other. The production of screw and bit is subject to tight tolerances and requires high precision.

If screws with HECO-Drive and HECO-Drive bits are used together, HECO guarantees the GripFit effect. This means that the screw fits precisely on the bit and is held securely by friction. The system does not work magnetically, but mechanically, and thus also works with stainless steel screws. Because of this, it is also possible to work with only one hand. In contrast to standard T-Drives, the screw does not wobble, which also makes it easier to apply and work with.

But because it is ultimately a variant of the T-Drive, the HECO-Drive is compatible in all directions: the screws can be screwed in with normal T-Drive bits, and the HECO-Drive bit can also be used for screws with normal T-Drives.

“We believe that with our HECO-Drive we are offering users a unique opportunity to make their work easier. The compatibility of the system with standard offers makes it doubly attractive,” explained Jakob Braun.

In addition to the range extensions with a view to variable drive sizes, HECO now also offers fitting screws with a diameter of 3.5 mm. The head diameter is optimised for fitting connections and thus guarantees – equipped with a T-Drive T15 – optimum fitting accuracy in standard fittings with 90° countersink. To meet the requirements of timber construction, this version is also available with milling pockets.

Klimas > Wood screws with new milling tip

Klimas wood screws are a group of products that are characterised by a unique solution – a new  milling tip. Now assembly can be up to 40% faster, says the firm. The new solution accelerates the “catching” of the wood and causes less resistance during screwing.

The screws are designed for fastening wooden structures together. They are ideally suited for the construction of roof trusses, building frames, connecting wooden beams, or during the construction of garden houses or pergolas. Klimas offers a wide range of fasteners dedicated to roofers and carpenters. These products are the subject of constant research and testing. Technological modifications affect the increase of standards and improve the ergonomics of work. One of the new solutions is the unique milling tip of the wood screws.

Wood screws with the new milling tip are a solution developed by the experts at Klimas, which responds to the specific needs of contractors. Tests conducted before the product was introduced confirmed that the new shape of the screw tip results in a decrease in screwing time by up to 40%.

A double thread on the tip makes it easier to “catch” the wood from the start – a handy feature for anyone who has tried to connect pieces in hard-to-reach places such as overhead. Then you just put the new edge into the wood, press down and turn it slightly, and the screw will stay in the substrate.

The special shape of the milling tip freely cuts through the wood fibres. This function is ensured by additional cutting edges that cut through the wood fibres so that the screw can be applied without predrilling.

The 20% lower resistance during screwing means on the one hand faster working times and on the other hand less battery consumption when using battery powered screwdrivers. The way in which the screw penetrates the wood is also influenced by the special wax coating, which significantly reduces the screw-in torque.

Before installation, the appropriate length of screws should be selected depending on the thickness of the elements and the minimum depth of anchoring. Wooden elements should be free of defects (knots, cracks, staining, defects in construction and shape, mechanical damage). The installation of wood screws should be carried out using a screwdriver and a suitable tip for the TX drive type.