Most doors that stick or bind, especially wooden doors, are caused by one or more of the following conditions:
Normally, there should be a uniform gap around the door, usually 1/8 - 1/16. The door should close smoothly and easily, latch firmly, and remain closed. Carefully observe the door as it operates and note where the binding or rubbing occurs. Does the binding appear to be at the top and/or bottom of the door only or on the hinge and/or latch side of the door only?
Table 1 lists some common problems with sticking or binding doors and possible corrective actions to take.
Steps to repairing a door:
Repairing holes in sheetrock, large or small, requires some of the same basic steps. If the hole is large, but not large enough to make the opening larger by going to the adjacent studs, the hole should be squared off as reasonably as possible.
Figure 1: Repairing a Hole in Drywall
If the hole were large enough to expand it to the existing studs, then supports would be required for the top and bottom portions of the hole.
Steps to repairing drywall:
The two most common types of door locks are the key-in-knob lock (Figure 2 and Figure 3) and the deadbolt (Figure 4). They can be installed in solid or hollow-core doors; however, a hollow-core door offers no security. Most key-in-knob and deadbolt locks purchased are included in a kit containing the lock, the attaching hardware, and a paper template used to mark new doors for the lock. They generally are installed in the same manner. The template is used to ensure correct backset from the door edge, providing the spacing for the latch and centering the latch in the hole in the door edge. The template is not required if the lock is being replaced. Attention must be paid to the location of the keyway. The keyway normally is installed on the exterior of the door. Most new door locks are not designated as either left- or right-handed. Standard sizes are 2 and 3/8 and 2 and 3/4 inches. Some locksets are adjustable between the two sizes.
Figure 2: Key-in-Knob Door Lock
Figure 3: Key-in-Knob Door Lock Parts
Figure 4: Deadbolt
Figure 5 shows a mortise lockset that can be found on many metal doors in large buildings.
Figure 5: Mortise Lockset
A lock, as defined by the International Association of Home Safety and Security Professionals, is: "a device that incorporates a bolt, cam, shackle, or switch in order to secure an object, such as a door, drawer, or machine, to a closed, opened, locked, off, or on position, and that provides a restricted means of releasing the object from that position."
There are various types of locks in use today. The basic types are:
A warded lock (Figure 6) is a fixed-position projection designed to prevent unauthorized keys from entering or operating the lock. One old type of warded lock comes in a metal case, has a large keyhole, and is operated with a bit key. Warded locks provide little security because wards are easy to bypass with a stiff piece of wire. This is the oldest lock still commonly used. It has a simple design, straightforward internal structure, and an easily duplicated key. The two types of warded locks currently in use are the surface mounted or the mortised lock Figure 7. A mortise is a cavity created to contain something. A mortised lock is installed in a cavity created in the door for the purpose of containing the lock.
Figure 6: Warded Lock
Figure 7: Warded Locks
Combination locks are used as alternatives to key operated locks. The two basic styles are pushbutton and dial.
Pushing a specific sequence of buttons operates pushbutton locks, which usually are labeled with letter or numbers. Rotating one or more dials to specific positions operates dial combination locks.
Electric current operates an electric lock. One type is basically a bolt or bar mechanism that does not have a keyed cylinder, knob, or turn-piece and cannot be operated mechanically. Another type, called an electrified lock, is a modified mechanical lock that can be operated either mechanically or with electricity. Electric switch locks complete and break the electrical current when an authorized key is inserted and turned.
Tumblers are small objects, usually made of metal, that move within a lock cylinder in ways that obstruct a locks operation until an authorized key or combination moves them into alignment.
These locks (Figure 8) are found on luggage, briefcases, and lockers and offer a low level of security. They can easily be defeated with a hairpin, knife, or screwdriver. However, the lever type can also be designed to offer a high degree of security, as with those used for safe-deposit boxes.
This lock requires a standard flat key. When the key is turned, the various key cuts raise the corresponding lever tumblers to the correct height; the gates of the levers align and release the bolt. The bolt stop must pass through the gating from the rear to the front or vice versa, either unlocking or locking the lock.
Figure 8: Lever Lock Tumbler Lock
These locks (Figure 9) are often found on desks, file cabinets, automobile doors, and glove compartments and offer a medium level of security. This type of lock gets its name from the shape of the tumblers. The disc tumblers are steel stampings arranged in slots in the cylinder core. The rectangular hold or cutout in the side of the disc matches a notch on the key bit. The protrusion on the side, known as the hook, locates the spring. The disc stack is arranged with alternating hooks, one on the right side of the lock and one on the left.
Figure 9: Disc Tumbler Lock
When the correct key is inserted and turned, the cuts in the key raise the tumblers high enough to clear the lower cylinder slot but not so high as to enter the upper cylinder slot. The key arranges the tumblers along the upper and lower shear lines, freeing the plug to rotate and throw the bolt.
This type of lock (Figure 10) provides a higher degree of security than other types of tumbler locks, usually medium- to high- security. These locks are used in most homes, high-security padlocks, automobile doors and ignitions, and many types of correctional facility locks. The basic parts of a pin tumbler include the cylinder case, the plug, the keyway, upper pin chambers, lower pin chambers, springs, drivers, and bottom pins.
Figure 10: Pin Tumbler Cylinder
The cylinder case houses all of the other parts of the cylinder. The part that rotates when the proper key is inserted is called the plug. The keyway is the opening in the plug that accepts the key. The drilled holes, usually five or six across the length of the plug, are called lower pin chambers, They each hold a bottom pin. The corresponding drilled holes in the cylinder case directly above the plug are called upper pin chambers; they each hold a spring and a driver.
When a key is not inserted into the cylinder, the downward pressure of the spring drives the drivers partially down into the plug to prevent the plug from being rotated (see Figure 11). Only the lower portions of the drivers are pushed in the plug because the plug holds the bottom pins. When a properly cut key is inserted, it causes the top of all the bottom pins and the bottom of all the drivers to meet at the shear line. When the pins are in this position, the plug is free to rotate to the open position.
Figure 11: Key in Cylinder
Figure 12: Rim Night Latch Installation
Most locks require little or no maintenance. If a lock is sticking, a little graphite applied to the keyway usually is sufficient to lubricate the inside of the lock.
There are many ways to remove a broken key from a lock. Much of it depends on the type of lock, how much of the key is broken off, and whether or not the door is open.
The tools required range from small needle-nose pliers to a professional key removal kit (Figure 13). The idea is to insert a thin piece of metal so as to be able to remove the broken piece from the cylinder.
Figure 13: Typical Key Extraction Tools
Other more elaborate removal procedures can be used, such as the following.
Figure 14: Key Removal Procedure Using Specialized Tools
In addition to using specialized tools, some simple methods may be applied to try and remove the broken key. A precision drill can be used to drill a small hole in the back of the key so that a spiral key extractor can be inserted into the hole to facilitate removal. In addition, a homemade device made from a small, thin saw blade or spring-steel fashioned to facilitate removal of the broken key.
Basic Steps for removing a broken key from a lock:
Learning to work with power tools safely is one of the most important aspects of building maintenance. In this section, we discussed carpentry, but the basic rules for working with power tools apply to all aspects of building maintenance, as well as working with them at home or off the job.
One of the most important things about power tools is never to use a tool you are unfamiliar with.