# R311.3.1 & r311.3.2



## conarb (Nov 4, 2012)

Under the 2007 CBC (2006 IBC) thresholds could only rise ½" over landings (interior floors) with a ¾" exception for sliding doors, I am not addressing the R-3 exception for exterior landings.

The 2010 CRC (2009 IRC) seems to have made this more reasonable to accommodate area rugs on the interior in front of doors,



			
				2010 CRC said:
			
		

> *R311.3.1 Floor elevations at the required egress doors.* Landings or floors at the required egress door shall not be more than 1½ inches (38 mm) lower than the top of the threshold.*Exception:* The exterior landing or floor shall not be more than 73/4 inches (196 mm) below the top of the threshold provided the door does not swing over the landing or floor.
> 
> *R311.3.2 Floor elevations for other exterior doors*. Doors other than the required egress door shall be provided with landings or floors not more than 7¾ inches (196 mm) below the top of the threshold.
> 
> *Exception:* A landing is not required where a stairway of two or fewer rise rs is located on the exterior side of the door, provided the door does not swing over the stairway.


For purposes of this question ignore the exterior threshold height, I take this to mean that in residences covered by the IRC door thresholds can now be 1½" higher than the interior floor for doors in the path of egress, and 7¾" above the interior floor on doors not in the path of egress?  That doesn't seem reasonable, what about trip hazard?


----------



## ICE (Nov 4, 2012)

conarb said:
			
		

> I take this to mean that in residences covered by the IRC door thresholds can now be 1½" higher than the interior floor for doors in the path of egress, and 7¾" above the interior floor on doors not in the path of egress?


You are correct.


----------



## steveray (Nov 5, 2012)

This is America Damnit! If you want to trip in your own house you can!.....But you can't spend alot of money on heating and cooling......!


----------



## rogerpa (Nov 6, 2012)

Dick:



> I take this to mean that in residences covered by the IRC door  thresholds can now be 1½" higher than the interior floor for doors in  the path of egress, and 7¾" above the *interior floor* on doors not in the  path of egress?  That doesn't seem reasonable, what about trip hazard?


The allowed (interior) threshold height in the IRC has always been 1-1/2". The 8" difference in elevation of the *landing on the exterior* side of the door to the top of the threshold was changed to 7-3/4" in 2003.

*2000 IRC*

*R312.1.2 Landings at doors.*

There shall be a floor or landing on each side of each exterior door.

*Exception:*

At the exterior side of sliding doors.

The floor or landing at a door shall not be more than1.5 inches (38 mm) lower than the top of the threshold.

*Exception:*

The  landing at an exterior doorway shall not be more than 8 inches (197 mm)  below the top of the threshold, provided that the door, other than an  exterior storm or screen door, does not swing over the landing.

Roger


----------



## Architect1281 (Nov 10, 2012)

Thresholds are an absolute hazard to not only occupants but to first responders; think of this poor guy with a too high threshold


----------

