My contractor just hung our fancy dancy un-painted solid wood door slabs in my 100 year old house with solid hardwood floors throughout. There is an approximately 1.5" gap at the bottom of the doors. I think it is too big and think a 1/4"-1/2" gap would accommodate any unevenness in our floors and allow us to use area rugs. Is there a standard size for the gap at the bottom of the door? If it is in fact too big, how do we fix it?

This was part of a major renovation that involved replacing all the trim and repairing damaged plaster. The areas around the doors were stripped down to the studs and headers, but the hardwood floors were left in place. There is no sort of threshold on the floor between the rooms as the hardwood floors run throughout the house.

  • 2
    Keep in mind that there should be some gap to allow return air to get out of the rooms for the A/C system (assuming there is one), but 1.5" seems excessive.
    – JPhi1618
    Commented Feb 28, 2018 at 20:47
  • 1.5" sounds like a lot unless you are adding carpet and a pad then it sounds about right to allow some return air like jphil1618 mentioned.
    – Ed Beal
    Commented Feb 28, 2018 at 23:06
  • This is the gap when closed or the minimum gap along the swing? If the floor is not flat or perpendicular to the door swing you may have to leave more of a gap. Otherwise seems a bit much.
    – Stanwood
    Commented Mar 1, 2018 at 0:26

5 Answers 5


The standard I use is 1/2" over finish floors, 3/4" is acceptable. To fix the issue the doors need to be removed, bottom of the jambs cut and reset the door.

I have never seen a door set with that big of a gap unless it was to get past floors that were not level. That is a lot of room for unlevel you have there.

IMHO, you hold the cash, have them fix it, only then they will receive the next payment.


There us also one other possibility. If you have HVAC and there is a grill in the room and there is no return in the same room, when the central heating/ cooling system is turned on it would create a high pressure in those rooms. Therefore sometimes a door cut higher is a viable solution to equalize the pressure. Removing the doors and cutting down the jambs IS NOT a viable alternative because the tops of doors and windows should plain out same height. I personally would do some type of detail on the bottom if the door if it was not necessary by design to equalize pressure. Get creative and there is a tremendous opportunity to do something quite unique. Such as a motion activated KED light strip as one example.

  • Hello, and welcome to Home Improvement. Thanks for the answer; keep 'em coming. And, you should probably take our tour so you'll know how best to contribute here. Commented Nov 17, 2019 at 21:29

The amount of Gap depends on your AC system. In the South we have big gaps, I do inch and a quarter. Square inches of the air return should equal the square inches under the door.

  • More precisely, the air return (the pathway for the air leaving the room) is in residential construction almost always under the doors. The square inches under the door should equal or exceed the square inches of the vent supplying the room. (Ex.: 3x12 vent = 36 sq in, 1x36 = 36 sq in, which is a match.)
    – MadMonty
    Commented Jan 10 at 21:32

Mostly 1/4inch and differ from the finished floor or level. However,traditional carpenters tend to think of the bottom sill set up. It could be their fixed habbits.


One other point: The gap is often set higher when the door needs to clear carpeting. And when carpeting is removed, nobody goes back to buy another door.

For outside doors, you should be considering a door sweep anyway.

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