As Vice President of Painting for my firm, I have vast experience on the proper techniques for repainting wooden surfaces in high traffic areas. The surface needs to be properly prepared. This is the most important step when painting or lacquering high traffic areas. If the existing coating is adhering properly and is in good shape, a hand sanding would be enough to properly prepare the surface for new paint. If the existing coating is failing (peeling, chipping, cracking), then it should be removed, either by chemically removing it, water blasting it and hand tooling it off. The substrate should then be primed and painted with paint that is recommended for those types of surfaces (i.e. floor and deck enamel). Signage is always a good way of warning people of slippery surfaces. Also, by putting an aggregate in the paint or primer, you would greatly eliminate the possibility of someone slipping. Pre-painting, always cone off the area of work and have visible signs. Post-painting, signage such as “Slippery when wet” is a necessary safety measure.