Electric Strike Installation Guide
Follow this guide and you will install a strike correctly everytime. As
we detail in this post, installing electric strikes successfully is mostly good
preparation, but when done right provides years of trouble-free use. We use
our test door to walk through the practical installation steps needed
to get it right. Even if you never will install a strike in your life, do you
know if your doors are right enough? In this note, we walk through the
steps needed to get it right, everytime.
The Steps
The process of installing strikes correctly is not complicated, but care
should be taken to perform each step:
- Door/Frame
Alignment
- Strike
Box/Jamb Prep
- Strike
Prep
- Power
Connections
- Final
Checks
If all the steps are followed, installing strikes can take minutes and
involve minimal troubleshooting. We cover the steps in detail below:
Door/Frame Alignment
Making sure the door and frame is aligned is a critical pre-requisite.
Strike Box Preparation
The next step is to cut the frame so the strike fits. Even 'zero
cutting' surface mount strikes used with surface hardware may require frame
modification, and it's a sure step when using mortise mount strikes. We break
down these steps into two parts depending on the frame:
- Factory
Notched Frames
- Field
Notched Frames
Factory Notched Frames: The scenario requiring the
least amount of prep work is a door frame factory notched to work with a
certain strike, as was the case with our door. However, even a factory notched
requires filing down sharp edges and bending or adjusting mounting tabs so they
do not interfere with the strike.
In our door, the strike pocket was slightly undersized so we had to use
a file to enlarge the opening. When performing this step, test fitting the
strike to the frame is helpful, with attention paid to potential spots where
the frame touches the strike. Any pressure or tight fit can warp the strike or
cause it to bind, and the strike should fit easily into the pocket.
Field Notched Frames: However, many frames are not
factory built to work with strikes, and more drastic modifications are
required. In many cases, the existing strike box (called a dust box) needs
to be cut out to make room for the new strike. The strike's installation manual
generally includes specific instructions to take when modifying the frame, and
the needed cuts can be made with a high-speed rotary tool (like Dremel)
for steel frames or with chisels for wood. The image below is a standard
example of the prep dimensions:
A good instructional video on how to cut out a mortise strike into a
wood frame can be found below:
Strike Prep
After the frame has been readied, fine tuning the strike for install is
next. That process follows these points:
- Fail
Safe Configuration
- Trim
Plate Installation (optional)
- Power
Cabling
We cover these steps in the video below:
Fail Safe Adjustment: Many electric strikes are
'field adjustable' for either power failure condition. Changing from one state
to the other usually entails changing position of springs, solenoids, or even
small levers. In the case of our strike, you must change the position of two
small screws hidden under a label:
Most strike installations will use a 'fail secure' position regardless
of where they are installed, and this is the default condition most are shipped
with. We confirmed our strike was configured correctly, and left it as shipped.
'Trim Plate' Installation: For sloppy cutouts that may be
unsightly or slightly oversized, most mortise strikes ship with an optional
trim piece that hides the cutout. This trim, called an 'enhancer' or 'skirt'
provides no security or operational benefit, just serves to cosmetically
improve sloppy preparation work.
Power Cabling: Many strikes ship as 'Dual Voltage' compatible, meaning they
operate given either 12 VDC or 24 VDC supplies. Some models include a dual
voltage transformer in the housing with a single pigtail, while others are sold
with two different pigtails trailing from the case. After confirming which
supply voltage is available, the strike can be configured for use, typically
involving twisting or jumping certain wire pairs together. The image below is
the example wiring diagram for our strike:
Final Installation
At this point most of the work is complete and the payoff is close.
There are just a few more check to make as the strike is finally installed into
the frame:
- Faceplate
Selection
- Power
Connections
- Installation/Shimming
- Final
Function Checks
These final steps are covered in the video below:
Faceplate Selection: Strikes generally ship with two or
more faceplates, and selecting the correct one is critical during use. The
'keeper' area of the strike is bigger than the door lock's latches, and the
faceplate narrows down the opening to match the specific type of door lock.
This increases the 'tamper resistence' of the installation by eliminating
potential gaps to insert prying tools behind the keeper.
Other door lock features, like the deadlatch, need a positive
surface to rest on when the door is closed, and the faceplate provides this
surface. Our strike was furnished with two options, and because it will be installed
with a mortise lockset, we will use the 'mortise faceplate':
Power Connections: Power cabling for strikes should be 'run-to'
rather than 'run-from' the strike. This means that the power cablings are most
easily routed from the source (typically a controller), through the frame, down
into the strike box. Especially when mortar shields are prepped into the frame,
the actual opening to run cable out of the box is likely difficult to find.
When using a fishtape or glowrods, they can be driven up and out of the frame,
taped to the end of the cables, and the power leads are drawn down into the
strike area.
Once the leads are in the box, they can be connected to the strike's
pigtails. The image below shows our strike, which included a factory snap-style
connector for both ends of the power splice:
Installation/Shimming: After power connections are made, the
strike body should be inserted into the strike box, being careful not to pinch
or crimp the cabling. If the prep beforehand has been done properly, this
should be one of the easiest steps in the process:
The strike itself is not ready for use without sandwiching the faceplate
down on top of the strike. At this point, with the faceplate seated onto the
strike, it should be secured into the frame with the included screws or bolts.
The strike itself should be square in the pocket, with no parts of the frame
touching the strike except for the mounting tabs.
If the strike appears to be too far forward or too far back into the
frame, or if it can be 'wiggled' in the enclosure, then shims should be
installed to take up the slack. Most strikes include shims and designate their
installation locations without causing interference to the strike's action. The
aim of shimming the strike is to give it a solid mount with the frame, not
compensate for alignment issues. If those conditions are noted, then we
recommend checking the squareness of the frame and alignment of the door.
Final Function Checks: At this point, the installer
should check the strike's alignment with lock. Visually confirming the latches
of the door lock are enclosed by the keeper is key. If the door latches do not
physically make contact with any part of the strike when the door is shut, then
the strike has been properly installed.
The goal of the installation is a strike flush mounted to the frame with
no backpressure on the door's latches. If these situations are noted, the
should be corrected before calling the job finished.
Final Thoughts
Most of strike installation is unglorious and even rough, but
doing the basic prep work is necessary for trouble-free use. If the installer
does a thorough job on the 98% preparation work, then actually installing the
strike is an easy 2% effort.
If you have any question, contact us.