Designers may be tempted to use characteristic design values in their designs as they are widely available for structural products coming from Europe.
European mass timber hardware suppliers are sometimes providing design guides based on “characteristic design values” or even “ultimate resistance values (Fu)” to the North American market. Characteristic design values may seem to provide reasonable resistance for the desired hardware, they are however tailored to the Eurocode, the building standard used in Europe. In fact, using characteristic design values in standard connection resistance equations within North American design standards may lead to dangerous overestimation of connection resistance. Eurocode uses a different calibration for design equations, the characteristic design values are typically:
Ultimate resistances should never be used in any design equation without the proper knowledge on how to factor down resistance values to either strength resistance values or reference design values.
On the other hand, MTC Solutions provides reliable and tested design values that are available for respective design standards in North America. and tested design values that are available for respective design standards in North America. All of the design values provided by MTC Solutions in our design guides are factored down so they can safely be used in North American design equations. MTC Solutions’ products have been extensively tested here in North America with North American wood species. The extensive product testing of MTC Solutions’ screws has resulted in ICC approval being awarded for the majority of our fasteners.