As often as not, when I approach a business with double doors (i.e. two doors, side-by-side covering one big opening, with hinges at the far left and far right) I find that one of the doors has a sign saying “PLEASE USE OTHER DOOR” - or in some cases, there’s no sign, and and your first clue that one door is locked is that you dislocate your shoulder trying to open it, or smack your face into it trying to walk through.
Why is this so common? Why are businesses reluctant to unlock both of the doors at the same time?
A lot of the time it is wind control. Unlocking the door that faces into the wind just funnels cold air into the building and insures that the door never closes properly.
I don’t know, but this is a good question. My dentist’s office has double doors entrance, but the right side is always locked. There’s no sign on it so you don’t know it’s locked until you yank on it. For the longest while I thought the door was broken, but after 14 years I have finally concluded that the door is permanently locked. Why, I do not know, because I have never thought to ask about it. I will next time, though. I might even raise a stink.
The Post Office where I go has doors that get a LOT of heavy use, and sometimes one side gets jammed.
An business copying place I know has two doors in a typical business suite: one is for their lab, with cutting machines and other heavy duty things. They don’t want anyone in there, but need the doors to bring supplies in.
A restaurant I can think of has a table close to the door, so if you open the right-hand door, it bumps into the table. Bad layout!
This always amused me: An office I visited regularly had a door on one wall with a large sign saying “THIS IS NOT A DOOR”.
Apparently there was stuff stored against it on the other side and it was kept locked. That didn’t sop people from trying to walk through it.
When I worked for the NHS, we moved into a new hospital. Naturally there were a lot of doors and they all had nice brass handles on both sides. The problem was that, in spite of notices saying “PUSH” or “PULL”, people assumed that the handle was meant for pulling. Consequently they tended to get ripped off. Eventually the management removed all the handles from the push side.
The secondary door needs to be able to secure itself to the head and sill, fixing it in place so that the primary door can be locked to it with a standard deadbolt or something similar. Yes you can lock two doors together with a big plank and brackets if you want to go all Medieval, or with key locks at the top or bottom, but those are hard to operate, not to mention irritating.
Instead this secondary door is usually secured with flush (recessed) or surface bolts at the top and bottom that are thrown with a lever or slider. http://www.realcarriagedoors.com/images/hardware/db/CB-FZ12.jpg Those can get gummed up and hard to operate, or over time the doors can get out of alignment so they can’t be so easily engaged into the receiving holes. Sometimes an impact to the door, like someone slamming into it, or being hit by a cart or whatever, can bend the pins so they can’t be retracted anymore. The lever ones are usually spring-loaded, and that spring can break, or get jammed, so it’s usually easier to just leave secondary door secured, especially if you’re a one-man shop and have trouble either bending over or reaching up very high.
Also, in this arrangement, having both doors operable only works if they each have closers and the primary door doesn’t have a latch. That can be a problem in windy environments. If you keep the secondary door fixed all the time, then the primary door can have a closer, no latch, and a lock; or it can have no closer, a latch, and a lock. That’s less hardware to break and maintain (closers are a bitch), it allows you to have a seemingly more grand entrance, and there’s still the flexibility of having a double door for moving in furniture or other equipment. In any case where you see this, the occupancy limits determined by the building code have to say that only one door is necessary, so you’re more likely to see this on small businesses.
I can think of two possible reasons beyond the ones above:[ul][li]Many double doors are constructed so that one door has locking pins extending vertically into the top jamb and the sill, and a second door that locks & unlocks “normally” by extending a deadbolt into the stile of the first door. This means that unlocking both doors takes an extra step when you arrive in the morning — and more importantly, re-locking them takes an extra step. If both doors are unlocked, and a dim-witted employee locks only the deadbolt when they leave at night without engaging the locking pins (hey, that’s how their door works at home!), then the door isn’t locked — pulling on the door handle will cause both doors to swing open. Better to only unlock the “normal” door with the deadbolt by default, and only unlock the second door when you need to get something large through the doors.[/li][li]Similarly, many double doors are designed so that one door has a piece of moulding that extends over the gap between the doors. (Not sure why, but my guess would be to cut down on drafts when the doors are properly closed.) For such a double door, the door without the moulding must close before the door with the moulding does, or the moulding will keep the first door from closing properly. With many people coming and going, this could happen many times a day. Again, better to keep the troublesome door closed unless it really needs to be open. [/li][/ul]
ETA: jjakucyk scooped me on the first explanation, probably because had not known the word “stile” in this context and decided to look it up.
In the case of the store I work at, the doors are push/pull, but one side is on a motor activated by a push button. If you try to manually open that door, there is considerable resistance until the motor kicks in, but it still opens to slow for people so invariably continue to push or pull on the door working against the motor and eventually it wears out and has to be repaired.
Ironically, there is a sign at eye-level indicating it’s an AUTOMATIC DOOR that people completely ignore and then get visibly annoyed by not being able to control the door. We don’t have a USE OTHER DOOR sign, but could be the reason why there would be a sign like that?
Wow, who would have thought that this topic could get so heated as to require moderation and lockdown of that thread?
Anyway, I have always assumed that the reasons behind this practice were fairly benign: perhaps nobody ever asks or is told how to do it. When I worked in a place with such doors, I would open them both but most people just opened one. There was no guidance provided. Of course, that’s in a place without a formal “please use other door” sign.
This practice bothers me because I figure that the double doors are sized for the building fire code requirements and leaving one latched makes emergency egress more dangerous. Nobody will be able to unlatch the top and bottom pins if there is a fire and people are rushing out. It surprises me that the fire marshal doesn’t have words with them.
In the case of restaurants in cold climates, it makes sense to have an extra door for fire safety reasons. What doesn’t make sense is using that door for entry when it subjects diners to blasts of cold air, and the main entrance has a vestibule that mitigates this problem.
If code requires both doors for fire egress, then they can’t have flush bolts or surface bolts to begin with, it would never pass inspection. They either need panic bars, like you see in schools and gyms, where pushing the bar in the middle retracts the bolts at the top and bottom, or they need to be un-latched and with closers like I described above. Because practically all businesses require two means of egress (front door and back/side door) the amount of egress width required per door isn’t usually all that big, and since the door must be 3’-0" wide regardless, that’s enough to cover quite a lot of occupants.
Where I work, when the wind hits the door at just the right angle, it will blow the door open rather forcefully. I don’t think it has ever broken the glass or damaged the hinges, but it often sounds like it is about to. So, on a windy day, we will prop that door shut, and put up a sign directing people to use the other door.
Cool… It makes sense that code would not allow it to be so easy to accidentally block a required emergency exit. Now that I know that I’ll stop fretting about whether stores open one or both doors.
Think maxwell smart. dada dadaaaa dadadaaaa dadum da dum da da dum.
Sore nose!
Double doors are dangerous. They tend to cause injuries because they close on the person.
The double door has to be held open permanently, which isn’t a good thing when it interferes with desired air conditioning (cooling , heating or dehumidify. )
Reminds me of the local hospital. Being a sort of short lived building, the state built it right at the ocean beach. The architects drew the plans, and then it was built, and the main entrance was … on the beach side. Imagine the salt spray with the afternoon breeze … often approaching a gale… on shore. Well they had rotating doors to block the wind entering the building, but the strong winds would make the doors rotate… pureed patient anyone ?
They built a new main entrance down in the sheltered street area ,with the lift and floor levels still saying "Basement - Main Entrance "
I am surprised no one mentioned that a locked door might stop a thief on the way out. ISTM that the locked doors (7-11) are the right-hand ones (facing out of the store) and that most people (who are right handed) would try to open that door when they are hurrying out of the store after a robbery. Next time you are in a convenience store, notice the ruler taped beside the door so the store can give an accurate height estimate to the police.
On the other hand, it might just be any of the reasons listed above.
The question there would be if the value of stopping a thief is greater than the cost of repairing a door the thief slammed into trying to escape. That could be bent locks, broken hinges, cracked or shattered glass, a bent door, or even damage to the frame. That could be thousands of dollars in repairs for a couple packs of cigarettes.
