Welcome to Q&A for Home Maintenance Q&A section, where you can ask questions and get answers from me and other members of the community.

Spam, self-promotion, questions with abusive, inappropriate language, and irrelevant questions will be deleted.
All of the questions are moderated!

You'll be notified when your question is answered. Please reply with Feedback to share whether a solution worked or didn't work. Thank you!

Connect on Google+
Find on Google+ Local

Legally, how large can the gap be at the bottom of an interior front door in a condo?

0 votes

I live in a condo in Chicago. I've always been annoyed that there is a gap of about 1.25" beneath everyone's front door which leads to the common hallway. Is it legal to have a gap that large under everyone's front door? I've heard that the gap needs to be smaller to meet fire codes.

My condo association is in the process of suing the builder for other obvious flaws they made in the construction of the building. I'm wondering if this shouldn't be added as it could be a fire safety issue.

Thanks so much!

asked in Condo Inspection by krista (120 points)
Share this question on your favorite network.

1 Answer

0 votes


Hi Krista,
Unfortunately I cannot fully answer your question because there are many variables involved. You’d probably need to contact Fire Department and consult it with them. 
There are different requirements that apply to a condominium door opening into the common corridor and they depend on things like building type classification (height, number of floors, etc.), number and type of exits from the unit, sprinkler system presence, building codes adopted and used at the time of building plans approval, etc.
For example, in buildings classified as a high-rise (I believe it’s over 75’ high) the gap underneath the apartment doors is required to deal with building’s stair and corridor pressurization. This must be properly balanced so you can easily open the doors and to deal with emergency situations such as fire. 
However, according to NFPA 80 (NFPA 80: Standard for Fire Doors and Other Opening Protectives):
The clearance under the bottom of the door shall be as follows:
A. The clearance between the bottom of the door and a raised noncombustible sill shall not exceed 3/8 in. (9.53 mm).
B. Where there is no sill, the clearance between the bottom of the door and the floor shall not exceed ¾ in. (19.1 mm).
C. The clearance between the bottom of the door and the rigid floor tile shall not exceed 5/8 in (15.9 mm).
Maybe your door is just missing a threshold?
Thresholds at doorways shall not exceed 3/4 inch (19.1 mm) in height above the finished floor or landing for sliding doors serving dwelling units or 1/2 inch (12.7 mm) above the finished floor or landing for other doors. Raised thresholds and floor level changes greater than 1/4 inch (6.4 mm) at doorways shall be beveled with a slope not greater than one unit vertical in two units horizontal (50-percent slope).
In smaller, other than high rise buildings, the requirements are different and may still vary between building structures / depend on the building’s design. They usually require tight fitting smoke and draft control door assemblies / fire rated type door (fire rating / time resistance to fire varies) / equipped with fire rated gaskets along the sides and the top edge / bottom gasket at threshold doesn’t have to be fire rated according to UBC (Uniform Building Code).
answered by darekrudy (21,730 points)