Advice: Using zinc-plated anchor screws in the facade

It is no secret, but many contractors do not know it: Anchor screws made of zinc-plated steel may also be used outdoors and offer an economic alternative to stainless steel screws. The European Technical Approvals/Assessments ETA-10/0035, ETA-12/0502 and ETA-15/0027 which are relevant for EJOT facade anchors say:

"The special screw made of galvanic zinc-plated steel may also be used outside, after careful installation and if the area of the screw head is protected against moisture and driving rain in such a way that no moisture can enter the anchor shaft. This requires facade cladding or rear-ventilated facade fixed in front of the screw head and the screw head has to be coated with a soft-plastic, permanently elastic, bitumen oil combination coat (e.g. car underbody coating or cavity protection)."
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Brush or spray can? 

It is not the process which is decisive for the functionality of this coating, but the quality of application. At the end of the day, a complete waterproofing of the screw head must be guaranteed. For this purpose, a soft-plastic bituminous paint can be done. In practice, a spray can with car underbody corrosion protection is used. A few short sprays are enough to prevent moisture penetration. A work step which takes only a few seconds.
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One or two short sprays are enough to protect the screw head from moisture and driving rain.