# How high can a transition to another room be?



## Gary Holiday (Mar 13, 2021)

I'm currently repurposing an existing building to be an apartment unit. The building is a slab on grade. There is a room that I laid 3/4 inch plywood down as a sub floor and to cover up the concrete that has cracked. The issue is, at the main entrance to the building I can not put down the 3/4 inch plywood because the front door would hit it and not open. So, now I have an entrance hallway that transitions to a room that is 3/4 inch higher. There is a door that separates these two rooms. Is this height difference an issue?


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## e hilton (Mar 13, 2021)

Only if you intend to pass code.  Going from bad memory (at my age it goes bad daily) I’m thinking 1/2” is max.


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## Rick18071 (Mar 14, 2021)

If the area you are in is using the 2015 IRC :


R311.3 Floors and landings at exterior doors. There shall
be a landing or floor on each side of each exterior door. The
width of each landing shall be not less than the door served.
*Every landing shall have a dimension of not less than 36
inches (914 mm) measured in the direction of travel. *The
slope at exterior landings shall not exceed 1/4 unit vertical in
12 units horizontal (2 percent).
Exception: Exterior balconies less than 60 square feet (5.6
m2) and only accessible from a door are permitted to have
a landing less than 36 inches (914 mm) measured in the
direction of travel.
R311.3.1 Floor elevations at the required egress doors.
Landings or finished floors at the required egress door
shall be not more than 11/2 inches (38 mm) lower than the
top of the threshold.
Exception: The landing or floor on the exterior side
shall be not more than 73/4 inches (196 mm) below the
top of the threshold provided the door does not swing
over the landing or floor.
Where exterior landings or floors serving the required
egress door are not at grade, they shall be provided with
access to grade by means of a ramp in accordance with
Section R311.8 or a stairway in accordance with Section
R311.7.

There is nothing in the IRC that requires the interior landing to be level or you that cannot have a change of floor height in the landing and there is no minimum height for a step.


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## e hilton (Mar 14, 2021)

I was thinking of ADA 4.5.2 that says anything higher than 1/2” requires a ramp in compliance with 4.7 or 4.8.


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## ICE (Mar 14, 2021)

Could the IBC apply?.....1003.5 Elevation change.


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## steveray (Mar 15, 2021)

Sayas apartment unit so I would assume IBC....1/2" or taper at 1:20 or flatter....


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## Rick18071 (Mar 15, 2021)

Sorry, I thought this was under the IRC since it was posted under residential building codes.


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## Rick18071 (Mar 15, 2021)

For apartments I use 2015 IBC:

1003.5 Elevation change. Where changes in elevation of less
than 12 inches (305 mm) exist in the means of egress, sloped
surfaces shall be used. Where the slope is greater than one
unit vertical in 20 units horizontal (5-percent slope), ramps
complying with Section 1012 shall be used. Where the difference
in elevation is 6 inches (152 mm) or less, the ramp shall
be equipped with either handrails or floor finish materials
that contrast with adjacent floor finish materials.


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## tbz (Mar 15, 2021)

I will assume the area around the door is greater than 63 inches away and as thus with a 3/4" rise you could laydown floor leveling compound starting 15" away from the 3/4" plywood and slope up to it.  1:20 is considered not a ramp, thus 15", if you want to ramp it then you need at least 9 inches; which is 75% of 12" for 1:12 maximum.

So a base length slope anywhere between 9 inches and more will suffice for your needs.


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