OK We put in some can lighting and used some roofing nails to secure them to joist.They have the little tabs that knock in that help hold them in place a co-worker says these are sufficient to mount but I disagreed and also use screws or nails in this case I used roofing nails along with the metal tabs that nail into the wood.Now another guy says this is not ok because they are for roofing and can`t be used as can or fixture supports. Well does he have a point? Kinda figure he`s right but those cans are not falling down besides the halo brand use a similar nail?