does leaving a hinged door open create additional pressure on the hinge?
August 9, 2022 1:34 PM   Subscribe

This is a low stakes question about... hinges, I guess, and/or doors.

Various members of my family leave shower doors, cabinet doors etc, open.

I feel like I've been told that leaving a door open like this puts more weight on the hinge, and will ultimately cause it to fail. But as I look at it, I can't see why that would be. It's not like it's supported on the bottom when it's closed. Seems like the weight of the door is always on the hinge. The angle's different, though, obviously.

Is leaving a door open actually harder on the hinge, or not?
posted by fingersandtoes to Home & Garden (12 answers total)
As with all things, it depends. A well-crafted door or gate does not rely on the catch or lockset to support the weight of the door. OTOH, a poorly constructed or hung door might. If you have to lift the door to shut it completely, then it's not well hung. Barring an auto-closing mechanism, a well hung door will just stay where you leave it, open, half-open or closed.
posted by SPrintF at 1:40 PM on August 9 [1 favorite]

When a door is closed, imagine that the screw heads holding the hinge to the door and wall are "facing" each other -- all weight is working on pulling the screws out of one side or the other, the threads of the screws are what's holding the hinge in place because the weight is trying to pull them straight out of their holes.

As the door is opened, the screws in the door side are always in the 'pulling against the threads' position, the direction of the weight doesn't change for those screws.

However, as the door opens the screws in the wall go from "pulling against the threads" to "pulling sideways" to "the hinges are pushing towards the wall" if the door is fully open and parallel to the wall.

(in a very generalized sense; if the hinges or door are out of square there's "twisting" movement to consider, and the bottom hinge has less "pulling away" weight than the top hinge does)
posted by AzraelBrown at 1:52 PM on August 9

There are potentially three different systems you would want to look at:

-The interface of the door to the hinge. You could draw out a vector diagram and determine that, no, the forces acting on the door itself are irrespective of its position. (I am assuming here that the other sides of the door are not supported, which they shouldn't be in a properly hung door.)

The hinge acting on the door exerts several forces:
1. A vertical force counteracting the force of gravity. This should be borne by the hinge plate, as it's ideally sunk into the wood of the door.
2. A tension force at the top hinge screws and a compressive force on the bottom hinge screws to counteract the moment of the cantilevered door attempting to rotate around its center of gravity.

-The hinge pin. Again, you can try to draw out a vector diagram using the inputs from the door:
1. A vertical force along the axis of the pins counteracting gravity.
2. Lateral forces against the pins counteracting the moment of the door.

These forces do not change when the door rotates. Depending on the construction of the hinge, its strength in various orientations may be different.

-The interface of the hinge with the jamb. This one is more interesting, because the forces actually do change here depending on the orientation of the door:

1. Again, vertical forces counteracting gravity.
2. The forces that counteract the moment of the door's weight will vary based on the orientation of the door. If the door is closed, these forces are compressive/tensile along the axis of the screws. If the door is open at a 90 degree angle, they will be shear forces across the diameter of the screws as well as a more complex set of compression and shear forces as the hinge plate attempts to rotate in its sunken position (again, assuming the door was installed correctly). If the door is ajar, it will be some combination of all of these depending on the angle of the door.

Based on this thought experiment, the most dynamic part of the door-hinge-jamb system is where the hinge is installed in the jamb. Whether it will wear out more quickly if the door is open would depend on a number of factors, but I think the big issue would be if the jamb was correctly cut out to accept the hinges. If those areas are too large, then the entire weight of the door would be born by the screws in shear, and screws generally don't hold shear forces as well as they do tensile forces.
posted by backseatpilot at 1:58 PM on August 9 [2 favorites]

Not particularly. If the hinges are well-made and well-attached, they'll easily support the weight of the door, open or closed.

Doors that latch will be supported on both sides when closed, so that lessens the torque on the hinges due to the door's weight.

But a poorly-attached door, e.g. with screws too short, or deteriorating wood, may worsen due to the stresses AzraelBrown mentions.

It's not something I've ever worried about. Most of the doors in my house are permanently open, and they all fit the frames as well as they ever did.
posted by pipeski at 1:59 PM on August 9 [1 favorite]

I mean with cabinets etc it definitely increases the probability that they’ll be bumped into which is annoying enough on its own and defin will add extra pressure.
posted by Hypatia at 2:02 PM on August 9 [4 favorites]

It depends on the door and the hinge. We left a baby gate open and the hinge pin was launched spectacularly across the room due to the pressure being put on the compressed spring in the hinge. So that wasn't safe.

But if you need a reason to keep cabinet doors shut, it's probably more likely someone will hit their head or hurt themselves on an open door.
posted by Polychrome at 2:37 PM on August 9 [1 favorite]

This shouldn't be an issue with most doors. With fence gates though, the fence is a lot less likely to fall over lengthwise than cross-wise so leaving the gate open could cause the fence to eventually sag. The hinges will be fine though.

Not bonking your head, keeping dust off of things, and aesthetics are the main reasons people like to return cupboard doors to a closed state.
posted by aubilenon at 2:46 PM on August 9 [1 favorite]

You wanting doors to be shut is enough reason for your family members to shut doors. Just saying.
posted by Dashy at 2:55 PM on August 9 [2 favorites]

Door hinges are not new technology. Experience has taught that the hinge should be quite sturdy. It shouldn't matter if the door is open or closed because it should be built to last for many years in both conditions. Even before the Internet, people love to tell people they're doing it wrong, whatever it is. meh.
posted by theora55 at 5:55 PM on August 9 [1 favorite]

Never had a hinge fail - however, I have had the screws loosen to the point they can no longer support the door as they have stripped their holes.
posted by rozcakj at 11:00 AM on August 10

Response by poster: Do I need to rephase this?

"Will leaving cabinet or shower doors open, over time, cause damage to the mechanism that holds the door on?"
posted by fingersandtoes at 11:15 AM on August 10

"Will leaving cabinet or shower doors open, over time, cause damage to the mechanism that holds the door on?"

posted by aubilenon at 11:32 AM on August 10

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