Fire rated oak interior doors
What You Need to Know about Oak Fire Doors : Fire Rated Oak Interior Doors
Quote from Article entitled What You Need to Know about Oak Fire Doors :
It is important to have signs notifying the users of a building that a certain door is a fire door, in order to ensure that it is left unobstructed and shut when it is not in use. These signs are not necessary when you fit them in your home. However, you should let every person in your home understand the importance of fitting the oak fire doors and the importance of keeping them unobstructed and properly shut all the time.
The full version of the article can be found here.