The commercial opening at Dura-Bar in Woodstock had to work with an automatic locking system rather than a key. That meant bringing the frame and the door to a state where an electric strike could be fitted and the latch would meet it, then fitting the strike and its supply.
A commercial opening does not accept an electric strike simply because the strike exists. The frame has to be cut to receive it, the door has to be prepared at the lock case, and the latch has to meet the strike squarely - because a door that only latches sometimes is worse than the arrangement it replaced.
This job was to make a commercial door operate with an automatic locking system. The electrical part is the last step; the work that decides whether it holds is in the frame and the door.
What the opening had to do
The door was to be released by an automatic locking system rather than by a key. On the door side that means an electric strike set into the frame in place of the fixed plate the latch closed against, because the strike is what holds the door and what lets it go.
It also means the opening has to be brought to a condition where that can be done properly: a frame sound enough to cut, a door prepared at the lock case, and a latch lined up with where the keeper will sit.
Cutting the frame for the strike
The frame gets a rectangular mortise cut at the latch position, deep enough for the strike body and its keeper. The cut is made to suit the strike being fitted rather than by eye, because once the strike is in, its adjustment range is small.
The wiring for the strike is brought through the same opening. On a steel jamb that is a cut through hollow section, so the edge is dressed and the cable kept clear of the raw steel it passes.
Preparing the door at the lock
The door is opened up at the lock case so the mechanism can be reached and the latch brought to the right position against the strike. On a steel door that is a cut in the face, which has to be closed up properly afterwards rather than left open.
This is also where the existing hardware gets checked. An electric strike releases whatever is presented to it, so a worn latch or a lock that is not throwing fully will show up here rather than be cured by the new strike.
Why the alignment decides it
The failure mode on this work is alignment. The keeper sits in a fixed place in the frame, and the latch has to arrive in it squarely and deep enough. A frame cut a few millimetres out, or a door that has dropped on its hinges, gives a door that latches on some days and not others.
So the line between door and frame is checked with the strike offered up before anything is fixed, and again with the door shut. It is a small share of the job by time, and it is the share that decides whether the job holds.
The job at Dura-Bar
The work was at Dura-Bar, 1800 W Lake Shore Dr, Woodstock, IL 60098, in McHenry County.
Woodstock sits inside the Illinois part of our service area. Building codes are adopted and enforced locally rather than being one regional rule, so where an opening has to satisfy something, the requirement is confirmed for that address instead of assumed.