We took over a construction project from bank several month ago. All the exterior doors are already installed. There is a steel door in between the interior of the house and the carport. I was wondering how do I tell if it is a firedoor. The sickness of the door is 1 3/4 inch. There is no label indicating it is a firedoor. The house is in San Jose California, and we are trying to pass final inspection.
rated frames and doors should have a metal tag on the door / frame indicating the rating & UL classification. without that i don't know of anyway other than trying to determine if the wall assembly is rated and making an educated guess.
not the best picture, but they look something like this:
If it is a rated door, it will have a tag from a testing agency. UL and Warnock-Hersey are the two big door testing agencies in the U.S. It could be on the top of the door or on the hinge edge. Usually an embossed tag, but sometimes just a printed metal tag. Whatever you do, DO NOT paint over it or remove it. If there is no tag and you can identify the manufacturer, you may be able to get a certification from them saying that it carries a rating. Most 1-3/4 solid cored doors have a minimum rating of 1/3 hour and won't necessarily have a label. These can be hung in an unrated jamb. Label requirements vary by jurisdiction. You'd need to check with your local building codes officer to find out what rating is required.
Whatever rating the separation wall is required to carry, the door can be one step less.