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I'm installing double interior doors for the master bedroom. Unlike many double door installations where one of the doors is locked into place with a flush bolt, these doors will each have a ball catch at the top. This will allow each door to be opened individually or both at the same time. I'm not concerned with having these doors lock.

The problem is that when you try to open both doors at the same time, the corner of the edges get slightly closer and the doors can jam into each other. I have considered the following possible solutions but I'm not sure what would be a good balance of practicality and esthetics:

  1. Leave the doors as is and get in the habit of opening the doors one at a time
  2. Increase the gap between the doors
  3. Add a radius to the inside corners

Even though I can see myself getting used to opening one door at a time, anyone unfamiliar with this quirk could make the doors jam into each other. I think that a larger gap will compromise privacy and make it look like an improper installation. I'm concerned a corner radius might make the gap between the doors look larger than it is or just not look right either.

Are there any other options I have not considered? What would you do?

enter image description here

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    I'd guess that unless each door is much narrower than a standard door opening, or you've got visions of royal grandeur where the footmen open both doors as Her Majesty approaches, you'll probably find you only open one at a time, simply for the convenience that it only takes one hand to do so. (ugh... spelling)
    – FreeMan
    Oct 8, 2021 at 13:02
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    I would have suggested three options ... the exact three that you did. I don't think any one of them is inherently better than the other. What would I do? I would latch one of the doors and use the other. But perhaps FreeMan is correct and you have a pair of footmen? Or maybe you would enjoy routing a pretty radius just for the fun of it? Pick the one you like.
    – jay613
    Oct 8, 2021 at 13:05
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    @FreeMan Both are true. These doors are rather narrow and I have visions of royal grandeur. Thanks for the laugh.
    – BahKoo
    Oct 8, 2021 at 14:51
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    Well, then, Your Highness, carry on!
    – FreeMan
    Oct 8, 2021 at 15:02
  • Option 4: Motorize the doors! Either with a remote control or a wall panel, have 3 "buttons" - open/close Left, open/close Right, open/close Both. Program the internal drivers so the "Both" option starts one door slightly before the other so there's no interference. Oct 8, 2021 at 15:13

4 Answers 4

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If you have a router, you can add a slope to the edge of the doors:

enter image description here

From the outside, this will look like they are touching, so it would probably look better than a radiused corner.

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    A router with a v-groove bit or a table or circular saw with the blade tipped a couple of degrees. The latch edge of a regular, single door is beveled slightly, just like this, so it only makes sense to do it with double doors. An angle finder would tell you what you've got on the front door of the house. Putting that same bevel on each of the double doors would probably be sufficient, though I'd be surprised if they weren't already beveled like that from the factory. May need to double the bevel angle to get both doors to open at the same time.
    – FreeMan
    Oct 8, 2021 at 11:37
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    Right ! Circular Saw would be a quicker way than router.
    – bobflux
    Oct 8, 2021 at 12:36
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    The traditional tool for putting a bevel on a door is a plane. Oct 8, 2021 at 14:00
  • you could also slope the edges as // rather than \/. That means one door needs to close first, though.
    – njzk2
    Oct 10, 2021 at 18:59
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So make the gap bigger and for privacy install a "soft" seal on one or both edges. That will fill the larger gap without causing locking.

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    Alternatively, a wooden strip on one door with an overlap for the gap, such that it cannot be opened without pushing the other door open in the process. The only problem with this is that you have to close the one with the strip on it first or it'll bang into the other door. But that's at least pretty obvious when you see doors with such a strip installed. (They're generally large enough to be obvious that's what they're designed for.) Oct 8, 2021 at 17:14
  • @Darrell the overlap can also conceal the relief you cut in that door. Oct 8, 2021 at 21:50
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A bifold door would open to one side, along a rail in the top lintel. That fits your need but changes the fundamental way the door works so may not suit.


Another option may be to work on the hinges, so that the virtual pivot point is moved. Kitchen cabinet hinges often have fanciness the allow their path to be slightly non-circular.

enter image description here

enter image description here Cabinet hinge with relocated center of motion.

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Such doors can not, generally, work with rotary hinges that only provide a rotational degree of freedom to the door panel. Basic kinematic informs us that it's impossible: you'll need to bevel the sides, or have an unsightly gap.

Instead of a simple hinge, a linkage-based hinge allows customizing the trajectory of the door, and it can be a combination of rotation and translation, and furthermore the axis of rotation can change its position along the door's travel. You'd want a design where the initial travel of the door is not just a pure rotation, but primarily a lateral translation to open up the gap. Close to the closed position, a point at the swing end of the door will be following a path that looks like ≺, and only later follow more-or-less an arc.

Unfortunately, such mechanisms often have to be custom made, because the understanding of such things seems to be largely lost among the trades, and thus there's little demand for such products.

If you know any eager mechanical engineers who could help you, it could be a fun project! Or, you could look for a planar mechanisms textbook. It will illustrate (IMHO) satisfying geometric solutions for planar linkage design that you could leverage to solve this problem. It can be a very hands-on project - don't be put off by the "theory" aspect of it. All that's needed is just a design procedure and a bit of understanding of terminology and the linkage types.

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  • "or have an unsightly gap" or a cover over that gap on the outward side.
    – Mast
    Oct 10, 2021 at 9:21
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    speaking of linkages, consider this - just for fun
    – davidbak
    Oct 10, 2021 at 17:27
  • @davidak That’s brilliant, thank you so much! I have an immediate use for such a door and will be putting it together soon. Excellent! Oct 12, 2021 at 15:09

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