Hi

please can you give me some info. If I was to paint yellow chevron markings and keep clear in front of a fire exit how wide and long does it need to be please.

Thanks

I would suggest you do not mark the floor, since some one could put boxes or similar around the markings, so that they have complied with your "keep the painted box clear" rule but still block the route to the fire exit.

I have only seen this method to define walkways in large factories and across roofs but if it solves your situation, so be it.

I am not aware of any guidance other than common sense and I would make it as wide as the fire exit opening plus additional width to cover any fire points adjacent to the fire exit. The depth would depend on the layout of the premises but about 1 m to 2 m would be sufficient.