Posted tagged ‘double doors’

Door Size Up #12


Door #12, Take a look and give it a shot.

Here we are looking at the backside of a commercial retail building. We have a 1 story masonry block building with a metal frame/jamb and a set of outward swinging metal double doors.  With it being outward swinging on the backside of a commercial it is fairly safe to assume that our primary lock is a panic bar or at least was at some point and may have been removed. We won’t know until we start to force it. You can ignore what appears to be two sets of black bolts both high and low on the middle of the two doors. These are holes from previous bolts that you would have been able to see.

We have an obvious bolt pattern showing that we have a secondary security feature to this door. This is a fairly run of the mill drop bar bolt pattern when we are looking from the outside. It may be a little more significant due to the three mounts per door instead of two, but it is still fairly common.

Once we see the inside it is apparent that this door is a little more secure than it appears from the outside. We can see that the stock panic bar is still in place and would be considered our primary lock. We have multiple secondary locks. If you look above the panic bar you can see we have a slide bolt that was blind from the outside. We also see our drop bar mount setup, which in this picture does not have the bar in place.


When we look closer at the drop bar mounts you can see they are designed much better than our typical setups. The mounts are one piece of steel instead of each set of bolts having its own mount. It is also welded to the skin of the door on both ends of the mount.

This presents a couple of problems that you wouldn’t normally find with individual mounts. The solid mount all the way across will make it very difficult if not impossible to drive these bolts through with a set of irons. As you attack one set of bolts, the other bolts will hold that steel mount in place preventing the heads from being driven through. The welds also add to these problems. If you attacked the bolts with a saw allowing the heads to fall off, you still have the welds holding the bar to the door. This is why it is important for us to move back and forth from conventional irons work and saw techniques. If we cut these bolts attempting to drop the mounts off, we may not realize that the welds are present until we go back to conventional techniques and try to pry the door open. Welds can be intimidating and when done right can add significant strength to a homemade security system, however when not done properly (especially when welded to the thin door skin) it can actually weaken the holding metal for the mounts. Either way after these bolts have been defeated we should attack this door conventionally again.

Lastly you can see the 3/8 inch steel drop bar that is put in place and goes all the way across both doors. This again stresses the importance of getting out into our buildings and recognizing the variables in these drop bar systems. It may just take away some of the surprise when we go to bat against them on the real thing. It is a decent set of doors, but with a solid Plan A, B and C  I am confident we can defeat them.

Door Size Up #10


This door is on the backside of a single story “L” shaped strip mall.  The store is used as an army surplus outlet.  Run down the key size up points and see what you think. The double doors are set in masonry construction.  What else do we see?

  1. Metal frame and metal jamb
  2. Outward swinging double metal doors
  3. Primary lock is key in knob
  4. Carriage bolt pattern on both doors indicative of a drop bar
  5. Carriage bolt pattern 18” above the lock suggestive of a hasp or possible slide bolt

The interior view of this door shows us what we are up against.  As we predicted we have a key in knob lock and a drop bar with a hasp that is padlocked.  There are several interesting points about this door.  As we could tell by the exterior picture, the seam where the doors come together has a wide gap (approximately 1/2”).  The occupant has attached a 1/8” piece of steel that runs the length of the doors to prevent anyone from trying to lift the drop bar out of place or manipulate the primary lock. These strips on the back of the door come standard on many double door setups, but many times occupants will fabricate their own to increase the security. This is the main reason you should force the lock side door when doing double doors. You want to force the one that closes last because that metal strip acts as a stop for the main door. If your pry on the secondary door you will be working against that strip.   Secondly, the drop bar is 1/4” steel that rests on two brackets on either door.  The weight and placement of the drop bar will be beneficial to us when we start to force entry.  The weight of this bar could be an advantage as we drive the carriage bolts through because it may cause the brackets to fail even quicker. Another thing to remember on double doors is to force the bolts on the primary door first, don’t waste your time taking all the bolts out across the whole door because it is not needed.  Also, note where the drop bar ends.  It only extends the width of the frame, greatly decreasing the degree of difficulty.  Lastly we have the hasp that is padlocked together.  This may offer a little more resistance because the lock is elevated slightly and will cause us to lose a little leverage when we force the door.  It should not be anything that we can’t overcome using the irons.

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