I’m currently going back and forth with a builder on what I think is a defect. When I close any bedroom door in the home, the gap between the door and the ground is ,in my opinion too big. The doors are 82 inches but the gap is almost 2/3 inches. I can literally stick my hand under the door with the door closed. Builder claims this is for ventilation purposes. Any advice ?!!
Builder is correct. Closing doors in a forced air heated/cooled home will prevent adequate HVAC air flow. Gap is needed to insure rooms are heated / cooled when privacy is required (bedroom doors closed at night).
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I concur with Bob unless your post is meaning 2” - 3” and not 2/3”.
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The door cut is absolutely a HVAC thing, and is common in some homes, especially Manufactured Homes.
IMO, you should be grateful the gap is ‘only’ 2/3". (Your cat would be pissed if it couldn’t stick it’s paw under the door)!
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Building codes require fresh air to be supplied to bedrooms. Often through a mechanical ventilation system that provides a specific rate of air change per hour.
The maximum allowed clearance between the bottom of the door and the floor is 3/4 inch (19 mm).
NFPA 80 code if my memory serves me well.
2/3rds" inch. All good. Ventilation/Circulation.
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I agree with others that the builder is correct. The gap under the door allows for return air to flow back to the return air intake, usually in the hall or common area.
I call out doors that lack a gap if the room doesn’t have its own return air.
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Common practice: Undercuts typically range from 1/2" to 3/4", so 11/16" sits comfortably within that range.
I find it odd for the door height to be 84” instead of 82”. Are there high ceilings in the rooms?
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quit wasting that builders time and appologize…you picked the wrong hill to die on….
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Why on earth waste your time fighting over something so trivial? Tell the buyer your opinion and move on. Let them fight it out if they see fit.
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When I was the finish guy on our crew, the boss said 1” at the bottom of every room door. Also clears the carpet.
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No high ceilings, and this was a question asked by my client (the buyer), which I also wanted clarification. Just by looking , the gap just seems a little big compared to other new construction homes I have done. Better safe than sorry!!!
Thank you !!
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Strange…I’m used to doors at 80” or 6’8”.
Higher end homes are taller yes.
Gap is good @ 2/3”
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The builder is just planning ahead for when shag carpet comes back into style.
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Some doors are required to have a minimum of one inch gap at the bottom.
Seen this is tons of new construction builds. Cheap way to get return air out the rooms with putting return ducts in the room or vents above the doorway if there is room which really looks horrible.
Anyway, it’s fine in my opinion.
Oh, your question was one of safety. What is your safety concern?
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To the OP… Pay attention to the SOP! You are not a code inspector. Stop being so gawd dam picky. Really… would your comment have any bearing on the value of the home? Stay in your lane.
Cheers
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Here is what I found on this subject:
IRC section M1601.1 requires that duct systems comply with ACCA Manual D, the appliance manufacturer’s installation instructions, or other approved methods. The actual requirement is in ACCA Manual D, which is incorporated by reference into the IRC. ACCA Manual D section 4-9 states that “An engineered, low resistance return path shall be provided from every room or space that receives supply air,” and defines low resistance as limiting velocity through a return path opening to no greater than 350 feet per minute. ACCA Manual D includes a “Door Cut chart” showing required clearances for various CFM flow rates. For example, a master bedroom with 400 CFM of supply air requires a 5.3-inch high opening under the door, and even 100 CFM requires more than a one-inch space under the door.
Generally, a single 6” round duct with a 4” X 10” boot and register flows about 100 CFM. For rooms with 100 CFM of supply, a door cut of about 1.5” with a 30” door will provide the low resistance path. See the submitted Manual J, D, and S documents for actual design supply and return CFM volumes. For master bedrooms, account for all supply air outlets in bathrooms and closets, including shower rooms, and toilet rooms. Master bedrooms may often have 200-300 CFM in the bedroom area and another 200+ CFM delivered to closets and bathrooms, requiring a 6” to 8” door cut.
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No point in having a door if you’re going to cut 5.3 inches off the bottom! 
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