When I renovated, I was required to install fire rated doors. All have a 1 hour rating. A 6 panel steel fire-rated door is not that expensive.

I don't know what they're called, but from what I've seen these are solid doors that essentially are full of sheet rock. It's the equivalent of three sheets of sheet rock stuck together inside a door veneer. Very heavy and rather costly. But if it saves a life.............. Good luck. BTE. you will also need an automatic door closer to go with that and a door viewer and a chain lock.

I wonder if anyone here has info on doors ratings. I want to replace a crappy door from the ground floor to the basement stairwell, but get confusing answers at the lumber yard as to what I need, forget about getting through to Buildings. Isn't what I need just a simple 20 minute rated mineral core door? For some reason I was told these aren't available.