Interior Door Height Off Floor

Figure 2 floor relative to entry door.

Interior door height off floor.

The standard height of the rough opening for a door is the door height plus 2 5 8 inches. The height of common doors is 6 feet 8 inches. Most entry door frames have a piece of lumber below the door and combined with the metal threshold will raise the base of the door off the concrete or wood sub floor by approximately 1 1 4 inches as shown in figure 2. I just took a quick look at some of standards and regulations governing door undercut which is the distance between a door and finished floor as opposed to clearance which is door to sub floor.

The standard i use is 1 2 over finish floors 3 4 is acceptable. The international building code has established doorknob height between 34 and 48 inches above a finished floor. On the inside of the entry door finished flooring is laid on the concrete or wood sub. I have never seen a door set with that big of a gap unless it was to get past floors that were not level.

To fix the issue the doors need to be removed bottom of the jambs cut and reset the door. The additional room allows for a 3 4 inch top jamb a shim. Installers typically drill the hole centered 36 inches above the floor if not specifically instructed to do so differently exceptions to the rule include doors that provide egress into swimming pools or other water features. The awi gives no minimum but a maximum of over 3 4 is unacceptable.