Flagpoles in Germany: aluminium, GRP, steel or wood?

The material determines how heavy a flagpole is, how it ages, how much care it needs and how it behaves in a storm. There is no specific legal requirement for the material in Germany. The state building codes do, however, require every structure to be stable and not to create dangers through weathering. Under the Model Building Code, this also applies to poles that need no building permit.

The materials compared

Aluminium

Aluminium is a common material for flagpoles in gardens, in front of businesses and at public buildings. The poles are usually tapered, thicker at the bottom than at the top, or cylindrical. The surface is often anodised or powder-coated, classically in silver or white. Aluminium does not rust, but forms a grey oxide layer in the air that protects the material. Depending on height and flag size, the trade gives pole diameters at the base of about 75 to 177 millimetres.

Glass-fibre reinforced plastic (GRP)

GRP poles are light and bend more in the wind than aluminium poles without breaking. They hardly conduct electricity when dry. That does not mean, however, that they are harmless near overhead lines: moisture and dirt can make the surface conductive. Over the years, UV radiation can make the surface matt and rough.

Steel

Steel poles are used above all where great heights and heavy flags create high forces. They are usually hot-dip galvanised and often additionally coated. Without intact corrosion protection, steel rusts, especially at the base and at points of damage.

Wood

Wooden poles are rare today and are mainly traditional in character. The best-known example is the maypole, which under building law counts as one of the masts erected for reasons of custom. As a flagpole, wood needs regular care, because moisture at the base and in cracks can lead to rot.

What building law requires

Under the Model Building Code, on which the state building codes are based, the following applies to every structure:

• Section 3: installations are to be built and maintained so that life and health are not endangered.
• Section 12: every structure must be stable as a whole and in its parts.
• Section 13: structures must be built so that no dangers arise from moisture and other chemical, physical or biological influences.

For design against wind, manufacturers use the wind load standard DIN EN 1991-1-4 with the German National Annex. The German Institute for Building Technology (DIBt) publishes which place falls into which wind zone. More in the guide to flagpole safety.

Material and lifespan

How long a pole lasts depends less on the material alone than on care, location and load. More in the guides to flagpole lifespan and flagpole maintenance.