My roof is made up of Fink trusses (chords in W shape). The trusses are made of 2x4s. The bottom edge of the truss acts as a ceiling joist and drywall sheets are attached below it, forming the ceiling.
Occasionally, I need to crawl into the attic for repairs. To make life easier, I laid some OSB boards across so I don't have to tiptoe on the joists (bottom edges of trusses).
However, looking at some questions on this site makes me think that this is a bad idea. Apparently, the trusses are designed to have just enough strength to carry themselves, the roof and ceiling and adding flooring would overload the truss. For example, this answer seems to suggest at least 2x8s are needed as joists.
Does this mean that when I crawl around the attic to fix a light fixture, I'm at risk of destroying my roof and ceiling?
Note, I am talking about occasional, brief maintenance access only. Not regular living or storage.