Schramberg screw producer HECO has gained ETA approval for its HECO-WB threaded rods as well an approval supplement for its HECO-TOPIC wood screw (for laminated beech veneer lumber), significantly broadening the applications for both products.
The HECO-WB threaded rods with timber thread now have European approval (ETA-19/0129) for joints in load-bearing timber structures. In the future, this will replace the previous general building inspectorate approval and facilitates Europe-wide use in safety-relevant constructions – with ETA approval, CE marking is now possible too.
Threaded rods approved for tensile and compressive reinforcement
Through the ETA approval, the use of HECO-WB threaded rods has been extended to more applications. In addition to strengthening transverse shear, tensile and compressive reinforcement, it’s now also possible without the time-consuming application of adhesive. An additional advantage is that the characteristic tensile strengths could be increased by about 10%, HECO added. This reduces the use of materials and offers greater freedom in processing. Possible applications include the reinforcement of gable roof girders, in curved girders as well as for penetrations, notches, and transverse connections in structural timber construction.
The galvanised, blue passivated threaded rods are available from HECO in two diameters – 16 and 20 millimetres – and with a uniform length of 3,000 mm. Before processing, they can be shortened in accordance with the approval. Connections with shorter threaded rod sections are now possible – depending on the diameter, either 128 or 160 mm.
HECO-TOPIX – ETA approval expanded
HECO-TOPIX wood screws allow for fast and safe assembly in timber construction without pre-drilling or counterboring, and have a reduced splitting effect. Through the ETA approval, the products may also now be used in laminated beech veneer lumber and hardwoods. This means the screws can be used more flexibly in a variety of applications in professional wood construction, such as staircase and interior design, in structural and general timber construction, in particular in the attachment of rafter-mounted insulations or facades.
Thanks to the performance of the screws, it has been possible to extend the requirements for fastenings owing to the approval supplement. It is now possible to process the TOPIX screws in all veneer lumbers, including softwood, at an angle of 0 to 90 degrees (previously 60 to 90 degrees). In the hardwoods ash, beech, and oak as well as in laminated veneer lumber of beech, the screws may be used without pre-drilling in accordance with the approval. Laminated and other beech veneer lumbers have their own thread extraction parameters, which are 2.5 times higher than in softwood. The head passage parameter is twice as high as other materials. Bolting can now be planned more precisely and economically.
Design software already updated
The approval extension has already been incorporated in the current version of the HECO-HCS design software. In the wood connection module, the different building materials can be selected. All approvals and declarations of performance for HECO fasteners are available on the HECO website.