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Door Sag

Which door is sagging?

Which door is sagging?

I have mentioned this before, but it bears revisiting.  Lock problems and door problems are often related.  If the door is does not swing or is not hung properly the lock may not work properly either.

I bring this up now because I was recently called upon to go out and do actual work. I am no longer used to this and will usually refuse these opportunities, but my daughter called to say that the restaurant where she is working was having problems with their walk-in wine cooler. This small, chilled room is unfortunately located near the entrance of the restaurant, around the corner from virtually all activity except exiting and entering. Should an unscrupulous patron give the grade one cylindrical storeroom function lock a tug on their way out, the door would swing open, inviting pilferage of some very expensive vintages ranging in the hundreds of dollars. Some might even qualify as grand theft. So she asked if I would come out and have a look, and being the wonderful dad I am I grabbed my toolbox and cordless drill and headed out.

I managed not to hurt myself, so I am grateful.

When I arrived on the scene, I noticed immediately that the door was sagging – that is to say, it was no longer square within the door frame.  I could tell because – as in the handy picture I provided above – I could see that the gap between the header and the door was noticeably larger on the lock side than on the hinge side of the door.  I checked the top hinge screws – often the culprit in these situations – but all was well up there and all the screws were tight.   This could mean only one thing:  the door frame had settled with the building and was no longer square.  As a result the latch no longer lined up with the electric strike and the lock would no longer latch.

saghingeSince the door was wood I could have pulled the door, removed the hinges, planed the hinge edge and re-cut the top and middle hinge mortises to bring the lock edge up and back in line with the frame; or I could broken into the walls on both sides and adjusted the door frame so it would be square again.  But because I am old, tired, and was not getting paid I decided to take the easy way out:  I shimmed the bottom hinge, forcing the lock side of the door slightly up so that the lock would once again align with the electric strike.

To shim the bottom hinge I simply put a washer behind the hinge at the location shown in the picture  at right.  Then I explained to the restaurant manager that this was a temporary fix and that later on the door would most likely need attention again because the problem would probably recur.

So I left everyone happy and with a working door, but also with a warning.  Since the door frame is no longer square it is likely to continue in the same direction and someone (not me) will have to address it in the future.


And once again I looked like a … Hardware Genius.

Securitech Lexi Electrified Exit Device Trim

Great Problem Solver

The Securitech Lexi series retrofit exit device trim is available with a variety of back plates and adapters that allow it to be used with most major brands, including many surface vertical rod and concealed vertical rod exit devices.  Compatibility with a variety of vertical rod devices is a major plus.

I mean, anybody can electrify a rim exit device by simply installing an electric strike.  However, while it is possible to install an electric strike on a vertical rod device it rarely brings a good result.  First of all, in order to use an electric strike you have to first lose the bottom rod.  That just leaves one latch at the top of the door to provide all the security.  If it is a tall door or a flexible door – like an aluminum storefront door – you can pull the bottom open several inches with just that top latch holding it.  Add a little time and a little hinge sag and pretty soon you have no security at all.

The other solution is electric latch retraction, or electric latch pullback, as some manufacturers call it:  relatively expensive compared with a Lexi trim.  Also, electric latch retraction is a fail secure only solution when locking trim is used and therefore may be inapplicable to fail safe installs such as stairwells, unless passage function (always unlocked) trims are used.

I notice that right out of the box the Lexi is very self contained.  Other than a tiny box containing mounting screws, tailpiece operators, and a cylinder collar and cam, what you see is pretty much what you get.  It’s pretty hefty for its size – it is designed on the slim side so as to be usable on narrow stile as well as hollow metal or wood doors.   This does mean that the installer may have to be a little creative when replacing a larger exit device trim with the Lexi.

Installation instructions are easy to follow and short – only four pages, including the template. Something I would have liked to see in the instructions, but didn’t, was current draw.  If I am installing one of these, the number of amps it draws are not going to matter much to me.  But if I am installing twenty of them and want a centralized power source, now it’s an issue.  Yet it isn’t anything that an experienced low voltage specialist with a ammeter can’t find out in two seconds.

One of the great innovations I noticed right away is the rotation restriction clip that allows the installer to customize tailpiece rotation to the exit device.  I do not think that this is handled better by any other manufacturer.  Correct degree of rotation often determines whether a trim will work or not, and to have a trim that has degree of rotation so easily selectable is damn nice.

As mentioned in the sales literature, since Securitech’s Lexi trim is compatible with so many exit devices, if you have a facility with different brands of exit devices dispersed throughout, you can install access control and unify the exterior appearance at the same time.  And in addition to being versatile it is also durable.  Forcing the lever only causes its internal clutch to break away, and it can easily be set right by rotating it back the other way.

All in all the Securitech Lexi trim seems to be a well built, versatile problem solver.  I think you’ll find it useful in many access control installations.

Door Problems

If the space between the door and the frame is different at the top than it is at the bottom, you've either got a door problem, or you're going to have a door problem.

As a locksmith I was called many times to fix what the customer thought was a lock problem only to find that the problem was with the door, not with the lock.   “What’s the difference?” you may well ask, proving to me that you are no locksmith.  “Well,” I would smugly reply, relishing my brief moment in the spotlight of useful knowledge.  “I’ll tell you.”  And I will, too.


Hardware and doors age together and develop different and sometimes incompatible symptoms of aging.  Like people, doors are subject to the prolonged effects of gravity.  Things start to sag, and for a while you can tighten things up and slow down or even perhaps reverse the effects, but eventually Newton will have his way and what was put up will come down.  That is to say the door, suspended an eighth of an inch (ideally) above the threshold, will eventually come to rest on that threshold.  If left to the ravages of time it will eventually cut a groove in the threshold.

Locks, meanwhile, start having trouble finding their strikes.  (A strike is to a lock what a tunnel is to a train or the side pocket to the eight ball.)  Usually (but not always) the strike stays put, but the lock travels downward along with the lock side of the door.  Eventually the lock may not line up with the strike at all, but before that there will be friction between the bolt or latch and the strike, making the lock difficult and eventually impossible to lock and/or unlock.

Besides sagging, wooden doors may warp and door frames of any construction may move as the building shifts and settles over time.  These changes may also result in locks that no longer line up and do not work properly.

Diagnoses and Remedies

The Sagging Door

Looking at the closed door from the ‘pull’ side, it is often easy to see if it is sagging.  If the jamb has not moved and was installed correctly, it is perfectly square.  Ideally there will be a one eighth inch gap between the top and the left and right edges of the door and the frame.  If the door hangs at an angle to the frame, it is probably sagging.

Marks on this ANSI 4-7/8 strike plate show that the latch has traveled down as it has traveled through time because of gravity.

If a door is sagging enough, there will be marks on the lock edge of the door where it is rubbing against the frame.

Often this is because the top hinge is loose.  If you tighten all the hinge screws this may solve the problem.  On a wooden door and/or frame you may find that the screws for the top hinge are stripped – that is, the screw hole has become enlarged because the weight of the door has pulled the screw out.  The solution for this situation may be longer screws.  Be sure you replace the screw with one of the same wire size so it fits flush in the countersunk screw hole of the hinge.  Commercial hinges use a size 12 screw, but bring one of the screws to the hardware store to match it up if you have any doubts.

Many times longer screws do not solve the problem because the wood door is not solid would, but particle core or gypsum core, or the frame is shimmed out from the studs so far that that there is nothing for a screw less than five inches long to grab.  In this case it might be necessary to relocate the top hinge (not generally a good result), install an additional hinge or hinges above and/or below the existing top hinge, install a reinforcing pivot hinge at the top of the door, or replace all the hinges with a continuous hinge.

Damaged Hinges and Crooked Door Jambs

If hinge tightening does not solve the problem, the hinge or hinges may be bent or the door frame may have shifted.

Hinges are often bent when someone (who is not too bright) places a piece of wood between the door and the frame to hold the door open.  It is possible to bend a hinge back to almost its original shape, but when it is bent the metal of the hinge is fatigued and it will never be the same.  Since hinges vary by manufacturer, it is best to replace all the hinges if one is bent unless you can find an exact replacement for the bent hinge.

If the hinges are neither loose nor bent, the door frame may be out of alignment.  Use a carpenter’s square to check the corners of the frame and a level to check the legs and header.

If it is a three-piece, knock down hollow metal frame in a sheet rock wall, you may find an adjustment screw at about eye level on each leg of the frame.  These vary widely between door manufacturers, so see what kind of driver may be required to turn the adjusting screw.   You can experiment with the adjusting screw to see if turning one or the other either way has any desirable effect.  Sometimes the adjustment screws are not connected to anything that has contact with anything else.  In that case turning the adjustment screws will have no effect.

Hollow metal frames that are installed in interior sheet rock walls are often secured to the wall at the bottom of each leg with a screw.  If the floor has shifted beneath the frame so that one leg is now lower than the other, it is possible to remove the screws from both sides of the leg, gently pry the leg up off the floor a little and insert shimming material beneath the leg to hold it up.

Wooden Doors and Frames

Wooden doors and frames are generally susceptible to more movement than hollow metal.  In addition to sagging, there is warping, twisting and swelling that may occur.  Fortunately whenever finished wood rubs up against something, it tends to leave a mark.  These marks can tell you what the door is up to and help you fix the problem.

Unlike a hollow metal or Fiberglas door, you can plane a wood door down.  Careful, though:  make sure you iron out any hinge problems before you start to plane, otherwise you’ll plane, the door will sag more, you’ll plane some more, the door will sag some more – pretty soon you’ll have a big space between the frame and the door someplace and you won’t need a door viewer anymore because you’ll be able to see out the crack.

One has no choice but to plane a door that has swollen.  Plane carefully, a little at a time, and do your best to keep the door as square as possible.  After planing, finish the door with paint, polyurethane or varnish – especially the edges – so that it doesn’t swell again so fast.

This is not a complete list of door problems, but it is a good sampling.  I hope it serves as a starting point for you to solve your own.

Hinge Basics ‐ Architectural and Residential Hinges

There is a huge variety of door hinges available in today’s commercial hardware market. Which hinge is right for your application? This article discusses hinge types, hinge characteristics, and basic guidelines
on how to choose a hinge for your application.

Parts of a Hinge
At right is an illustration that details the components of a full mortise hinge. Pictured is the most common hinge used in the United States, a five knuckle, full mortise ball bearing architectural grade template hinge, four-and-a-half by four-and-a-half inches.

  • The leaves are fastened to the door and door frame.
  • The bearings keep the hinge alligned help the hinge last longer by reducing wear
  • The pin (shown slightly withdrawn from the knuckles as if being removed) holds the leaves together and provides the axis on which the door will turn
  • The knuckle is a loop of metal through which the pin passes
  • The top tip rests on the top knuckle of the hinge, stabilizing the pin; the bottom tip is attached to the bottom knuckle and helps keep the interior of the knuckles clean.

Some Variations

The leaves could be equal widths, or unequal; the leaves could be “swaged”, meaning bent to compensate for a door with a beveled edge; the bearings could be ball bearings, concealed bearings, lube bearings, or “plain bearings”, indicating no bearings at all; the pin could be non-removeable or fixed; there could be five knuckles, three knuckles, or in some cases, no knuckles; and hinge tips could be decorative or could serve a purpose, such as hospital tips, which are beveled to prevent things from getting caught on them.

Commercial architectural grade hinges could be standard weight or heavy weight; they could have square corners or round; and they could be “template” or “non-template” hinges, indicating whether its screw pattern matches architectural conventions so as to fit in standard hollow metal door preps or not.

Electrical options are also available, such as electric though wire, concealed magnetic contact, exposed electrical conctact, and others.

Hinge Sizing

To measure a full mortise hinge, also called a butt hinge, lay it on a flat surface.  Measure the height, then the width.  When you specify full mortise hinge sizes, always refer to the height first, then the width.

Heavy Weight vs. Standard Weight Hinges

Heavy weight hinges are used for very heavy doors or doors that are subjected to very high traffic. Hinge “weight” actually refers to hinge leaf thickness. Heavy weight hinges leaves run closer to .200 gauge thickness, while standard weight hinges are more in the range .150 gauge thickness.

Hinge thickness is also dependent on hinge size. For example, a standard weight hinge 6 inches by 5 inches will be thicker than a standard weight hinge that is 4-1/2 by 4-1/2 inches.

Wide Throw Hinges

At right is shown a wide throw full mortise hinge. Wide throw hinges enable a door to open 180 degrees when a decorative door molding might otherwise prevent it from doing so.

Types of Hinges

All the hinges lifted below are available in standard weightand heavy weight versions for different commercialapplications. Illustrations at right show various kinds ofhinges.

Full Mortise Hinges

As I said earlier, full mortise hinges are by far the mostcommon type of hinge. They come in a wide variety toaccommodate diverse applications.

Half Mortise Hinges

Half mortise hinges are hinges that have one leaf mountedto the visible front of the frame and the other leaf mountedin a hinge prep, or mortise, on the edge of the door.

Half Surface Hinges

Half surface hinges are hinges that have one leaf mountedto the surface of the door and the other leaf mounted intoa hinge prep on the jamb part of the door frame.

Full Surface Hinges

Full surface hinges have both leaves visible when the dooris closed. One leaf is fastened to the surface of the frameand the other to the surface of the door.

Swing Clear Hinges

Swing clear hinges are designed so that when the door isopened to 90 degrees, the door itself is completely out ofthe opening.  For example, if you needed to move a cartthrough a door that was 35-1/2 inches wide through a 36inch wide door, unless the door was hung on swing clearhinges, you would have to be able to open the door 180degrees in order to get the cart through the opening.

All of the hinges above are available in swing clear versions.

Template and Non-Template Hinges

“Template” hinges are full hinges that have a standard screw pattern and sizing to fit into an ANSI  standard hinge prep, usually on a hollow metal door andframe. Most architectural (commercial) grade hinges aretemplate hinges. Most residential hinges are nontemplatehinges.

Radius Corners

Radius corner hinges are hinges with roundedcorners. “Radius” refers to the radius of the circle thatwould exist if the curve of the rounded corner werecontinued to form a circle.Architectural hinges are available with 1/4-inch radius corners whereas residential hinges are available in 1/4-inch radius and 5/8 inch radius corners.

Residential Hinges

Residential hinges are very simliar to architectural hinges, but there are differences. As stated above,more often residential hinges are non-template hinges, but they are sized the same as architecturalhinges. Residential hinges also more often have radius corners than architectural hinges and areusually made of thinner gauge metal. Often one will see an architectural grade hinge used on exteriordoors and residential grade hinges used on doors within the dwelling.

Spring Hinges

Spring hinges are architectural hinges that are springloaded so as to shut the door. They are available in fullmortise, with or without radius corner, in most sizes inwhich other full mortise hinges are made, and areavailable in template and nontemplateversions. A full mortise spring hinge is shown at right.  Beneath the full mortise spring hinge is a picture of adouble acting spring hinge for a door that swings bothways. Bommer Industries is an excellent source for a wide variety of spring hinges, as well as other architectural and residential grade hinges.  It is important to note that spring hinges are not a substitute for a door closer, since spring hinges slam the door.

Continuous Hinges

Continuous hinges are hinges that extend the full height of the door. They are widely used on aluminumstorefront and hollow metal applications. They are a good alternative for high frequency of useapplications where added durability is necessary. Continuous hinges are available in aluminum, steel,or stainless steel, and, like architectural hinges, are available in different types to accomodate differentconditions. Many of these configurations match those discussed in this article.

Pivot Hinges

Pivot hinges are used on very heavy doors in high traffic applications and on many aluminum storefront doors.  Since the weight of the door rests on the bottom pivot, thedoor does not “hang” as it does with other types of hinges, therefore there is less risk that the door will sag over time.  At right is a drawing from Rixson Hardware’s pivot catalog.

Electrified Hinges

Full mortise, pivot, continuous hinges and others are available with electrical options such as:

  • Electric Through Wire:  a number of conductors arethreaded through the hinge in order to conduct electricity from the door frame into the door (or vice versa) to power electric locks or transmit contact closure from monitor switches in the door or in the locking hardware. Available with anywhere from 2 to12 conductors, typically 24 gauge wire. 2conductor,18 gauge wire is also available.
  • Concealed Magnetic Contact: a magnetic contact reed switch is concealed in the leaves of a full mortise hinge. When the door is opened, the leaves are spread apart, breaking or making the contact. HInges with concealed magnetic contact are handed.It is possible to have both the above options in the same hinge.

Non-Removable Pins

In situations where you have an out-swinging secured door, you can use hinges with non-removable hinge pins. Non-removable hinge pins are pins which have a groove milled in them in the middle. A set screw is threaded through the middle knuckle to mate with the groove (see picture at right) to inhibit burglars from pulling the pin and the door to gain entry.  (In the picture, the center knuckle is not shown so that theset screw can be seen.)