An Earnest Proposal for Solving the Problem of False Alarms - Part 2

Bill Warnock takes an in-depth look at the physical and electromagnetic factors that affect false alarms

  • Is the building one story, two story or multiple stories?
  • Does the building have an attic, crawl space, storage area, and maintenance area, garage parking, basement and/or sub-basement?
  • What is the exterior composed of: wood, brick, poured concrete, cinder block, aluminum, steel or wood siding or combinations thereof? If it is concrete, is the ferrite content known?
  • What are the thickness of the exterior walls to include make and type of insulation?
  • What are the dimensions of the building, length, width and height?
  • Are there any exterior wall vent openings, number, location and type? Are there any bars, grills, and expanded metal mesh or like material covering the opening?
  • How many exterior doors are there? Where are they located, what type are they (wood, solid or hollow core, metal or metal clad or glass) and how are they installed?

Now as we get into more intricate construction, let's examine some construction terminology before we move forward.


  • Simple butt cannot be taken apart. Use RH or LH doors.
  • Loose-pin permits removal of door without unscrewing hinges.
  • Loose-joint permits removal of door without disturbing hinges or pin.
  • Rising butt is used when heavy carpeting interferes with opening of door. As door is swung open, the door rises slightly to clear the carpeting.
  • Ball bearings are permanently lubricated. They are recommended for heavy doors opening outward.

Door and Opening Parts

Here's the terminology: Top rail, stile extension, panel lock rail, hinge stile, latch stile, stile extension and bottom rail. Don't forget casing, head jamb, stop, jamb, saddle or threshold. And the he mullion is the middle casing for double doors.

A word of explanation is needed here. Construction standards leave a lot to be desired. To avoid complications and facilitate volume buying of door and frame combinations, the buck, or hole cut for a door, are often oversized, usually by one or two inches.

When the frame and door are installed, the space between the edge of the buck and the frame are filled with wooden wedges at two or three points, then plastered or trimmed over. In a relatively short period of time the wedges loosen after repeated opening and closing of the door, and the frame begins to float in the resulting air space or void.

To facilitate illegal entry, a modified car jack or fireman's frame spreader is placed just above the doorknob and or keyway. The spreader evenly applies pressure to both latch and hinge frames. The door yawns open. If rubber cups or padding are used, no marks will be left. Since wood and metal have memory, the frame quickly returns to its original position and form when briefly prized apart. When law enforcement responds to an alarm, they find all doors closed and locked and they report the dispatch as a false alarm.

When the owner returns and finds missing property and calls law enforcement, the report of a false alarm may put his insurance claim in jeopardy.

Here are some questions you have to ask about each door:

  • What is the direction of swing: right or left?
  • Brand name and type of locking device(s), rim, mortise, cylindrical, dead bolt? Vertical or horizontal? At least 2 inches long and single or double cylinder?
  • If there is more than one locking device on the door? If so, which one is used as the primary lock?
  • Did the builder, former owner or current owner install the locking device? If installed by the builder, how many dwellings did that builder in that locale construct?
  • Is there any locking hardware within 40 inches of any glass panel?
  • What type of hinges are used: simple butt or loose-pin? If loose-pin, are pins exposed? What are the lengths and type of screws securing hinges in frame and door?
  • In regards to the doorway, what are physical conditions of exterior and interior casings, head jamb, side jambs, and threshold? Is the side jamb framing made of metal or wooden 4x4s, double or single 2x4s? Are filler studs used? How are they held in place? Is there a double header securing the head jamb? Can side jambs be spread apart to compromise the locking device?
  • Consider the faceplate. What is the physical condition of recess, if any? What are the lengths of screws securing faceplate?
  • Strike plate recess or box? What is the depth and condition of recess and length of screws securing strike plate?
  • Is there a viewer installed in the door? What is its field of view? Is the viewer equipped with an interior swinging cover?
  • Are supplementary security devices used, if so what are they?

What is condition of the doorway, exterior and interior casings, head jamb, side jambs, threshold and rails? Is side jamb framing made of metal or wooden 4 x 4s, double or single 2 x 4s? Are filler studs used? Can side jambs be spread apart to compromise the locking device? Can sliding door be raised from either top track or bottom rail? Have large headed screws been inserted into the head jamb and framing at both ends and in middle?