Cleaning road signs

How should road signs be cleaned to avoid damaging their reflective surface?

Road signs should be cleaned at regular intervals to ensure that the sign retains the best possible reflectivity. Changes to reflectivity influence how easy the road sign is to see. Additionally, dirt may damage the surface of the reflective film and consequently shorten its service life.

Road signs can be washed mechanically, in which case we recommend using a rotating device with soft brushes. Please note that when pressure cleaning, the detergent must not exceed 50 bar. In addition, the jet of water must be at right angles to the sign and the sprayed water must not come out in a sharp point but must instead form into a fog or mist. Road signs must not be washed at temperatures below -10°C, and the washing water must not exceed +50°C. The cleaning process must not be abrasive and strongly aromatic solvents or solvents containing alcohol must not be used. If a detergent is used for washing, the signs must be rinsed after the wash. 

Signs can also be washed by hand, in which case we recommend using a soft brush or mop. The same instructions regarding the circumstances and the use of detergents apply to washing by hand as for mechanical washing.