Before the first winter in the house the question arises of when snow would need to be removed from the roof. One neighbour mentions a fixed number of centimetres, another refers to the age of the construction. Have the handling of the actual building clarified. A generally observed snow depth neither replaces an assessment of the roof nor a secure clearing plan.
Do not confuse weight and depth
The Federal Office of Civil Protection and Disaster Assistance (Bundesamt für Bevölkerungsschutz und Katastrophenhilfe) emphasises that for snow load it is the weight and not the depth alone that is decisive. It particularly recommends an assessment of the load-bearing capacity against high snow loads for older existing buildings and points out the dangers of incorrect roof clearing. [SCHNEE] The article does not state any general load value and no own measurement method.
Our editorial recommendation: gather available roof and structural documentation. Which construction is actually present, which changes are known and which information is missing? The competent specialist authority should explain what basis is required for your building.
Consider building parts and access as an overall task
Also describe any existing extensions and areas below eaves. The BBK names sliding snow masses and ice as possible hazards for lower-lying parts and people. [SCHNEE] Which areas of your house may be affected must be assessed individually.
Please ask the specialist authority to include existing fixtures and the suitable access in any required planning. Roof windows or installations are not treated as load-bearing stepping surfaces. The article does not allow a private roof inspection nor a specific clearing direction or choice of tools.
Know the contact person before the event
Clarify who will take over the building-related assessment and necessary measures in a corresponding situation. Which reliably accessible information is helpful for this and how should feedback be provided? A reachable contact and available documentation are more sensible than an improvised ascent in snowfall.
Observe official warnings and suitable current advice. In the case of an acute danger appropriate assistance takes precedence. This article contains no own all-clear based on a photo or the absence of visible deformations.
Fictitious case: the centimetre figure does not become the threshold
An owner accepts from acquaintances the statement that nothing needs to happen up to a certain snow depth. Instead, he has the existing roof inventory and the necessary handling of it professionally assigned. For a possible clearing the actual prerequisites are clarified before anyone steps onto the roof.
The result is a prepared precaution for a specific building. It is not a static proof, no traffic-safety statement and no clearance for clearing. A known snow load zone alone also does not replace this individual clarification.