In order to prevent contractors and homeowners from becoming liable for storm damages caused by an unsecured roof, the German Association of the Roofing Trade has tightened the Trade Regulations in 2011 already. The rule, which is legally binding for roofers and carpenters, specifies the use of tested storm clips for all new roof installations. Although, from a legal perspective, its compulsory for house owners, planners and contractors to secure roofing tiles, the necessity is still being questioned today. Here is an interview on this topic with Michael Wecker, Sales Manager of Friedrich Ossenberg-Schule (FOS), manufacturer of storms clips in Hemer, Germany.
Question: Should homeowners, planners, roofers and carpenters located in regions where storms rarely happen, be concerned about storm protection?
MW: We are all witnessing that our climate is changing. One consequence is that some storms now develop in regions, where they have not before. For this reason, some sections of pitched roofs across all wind zones need to be secured with storm clips (in accordance with the German Roof Trade Regulations and the Eurocode). These metal clips, which should be, corrosion resistant at a minimum, secure roof tiles onto the batten. Hence, preventing tiles from lifting off during times of strong wind. This is where the term "professional wind up-lift protection" comes from, but "storm protection" is probably better known among homeowners.
Question: What is the legal obligation for roofers, if they get a written confirmation from the builder or homeowner, that they do not want to implement storm safety? Are they off the hook?
MW: Legal liability will remain with the installer and tradesman, please refer to § 319 of the German Criminal Code regarding construction hazards and negligent injury or homicide. The tradesman cannot "free himself" by an agreement, he can only protect himself by rejecting such a contract in his own interest.
Question: Wouldn’t it be a disadvantage for contractors to integrate professional storm safety into their quotations, compared to competitors, who don’t include it and therefor look less competitive?
MW: The roofer or carpenter can turn this alleged disadvantage to his advantage by offering the storm protection as an additional point in his quotation. Together with a reference to the legal situation and an attachment with the wind up-lift calculation for the object, he can emphasize his competence as a roof specialist.
Question: Why is wind up-lift calculation essential for each object really? Why can't the whole roof be fixed according to a simple fixing pattern?
MW: A three-minute calculation can save three hours of work on the roof. At www.fos.de we offer the wind up-lift calculation tool FOS WindCHECK. The results are displayed in a PDF: it contains the type and number of clips as well as an outline of the roof, with details if and which section need to be fastened. The areas surrounding roof obstructions usually have a different installation pattern than the middle or eave section. The PDF can be stored in the WindCHECK archive and can be retrieved when required. A building-specific wind up-lift calculation is an integral part of the project documentation. In case of damage, the installer would be able to prove the wind up-lift protection was adhered to according to trade rules. It also reduces the number of storm brackets required. This saves installers money on materials and time during installation.
Question: A large variety of roof tiles are used throughout Europe. Due to these variations, many different clip shapes and types are offered - how do roofers determine the right fitting clip? Why can’t they always use the same storm clip?
MW: To ensure that the storm clip meets the requirements of the German trade rule and the Eurocode, it is crucial, that the clip fits the roofing tile and battens perfectly. We call the combination of these three elements: fixing, roof tile and substructure allocation. All current allocations stored in the WindCHECK have been tested according to the standard EN 14437 and have an up-lift resistance, that should be at least equal to or greater than the wind load on the building. By calculating with the WindCHECK tool, the user receives a list of clips, which can be used for the object. Now the user just has to select their preferred clip and receive the relevant results of the wind up-lift calculation. Storm? – yes, safe and secure!
Mr Wecker, thank you for your time!