Solid Steel Door Jam (or Brace) for Security

This design is superior to products you can buy premade for $15 up to $75. Commercial door jams are necessarily made to be adjustable, with most involving telescoping tubes kept in place with rounded, hollow pins on springs. The semi-circular brackets which go around the door knob are usually molded plastic -- either weak and brittle or soft and flexible. The commercial versions' rubber feet are usually less than half the surface area of mine, and may lack a leveling mechanism to optimally grip the floor. Lastly, manufactured door jams are made of inferior materials -- plastic and aluminum tubing, rarely steel.

The door jam can "harden" your exterior entrances, secure any room inside the house (in case of home invasions, crazy roommates, or domestic abusers), or ensure that the door will stay shut as you're doing your TRX or resistance band exercises on the "wrong" (that is, openable) side.

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Step 1: Tools and Materials


pipe cutter with capacity of at least one inch - $15.98

disposable cardboard and mixers for epoxy (e.g., toothpicks and paper plates) - salvage

scrap plastic wrapping to keep epoxy off of clean areas such as the door knob - salvage


heavy duty screw-in tool hanger with soft vinyl coating - $1.89

length of metro/intermetro shelving tubing - salvage

PC-7 heavy duty epoxy (alternative: JB Weld, but it is drippy and difficult to manage) - $5.99

large, heavy duty, rubber bottomed leveling foot - 3 for $15 shipped from eBay seller.

Step 2: Epoxy Socks

In order to prevent gross misalignment of the feet inside the tubing, precoat the threads with some epoxy, but not too much to fit inside the tubing. Let this cure for a day.

You can do the same with the hammer hooks. It will be desirable to attach the hook at an angle to the tubing, but some epoxy socks help very much to stabilize the setup for the final epoxying step.

Step 3: Attach the Leveling Foot

Stuff some scrap paper down into the tubing in order to serve as a stopper to retain the epoxy while it is curing. Push the paper wad down inside using the foot itself, to put it at the perfect position. Make sure to leave a little gap between the foot and the edge of tubing in order to allow the foot to assume an angle when in use.

Fill the remaining space around the foot support (the bolt) with freshly mixed epoxy and allow to cure in a straight up position. Be careful not to spill epoxy onto the angling mechanism of the foot.

Clean any epoxy mess with water right away.

If necessary, place a temporary spacer between the foot and the tubing to maintain the gap while the epoxy cures.

Never adjust things after the epoxy has begun to stiffen as that badly compromises the strength of the bond.

Step 4: Cut the Tubing to Length

It's important to have the door at hand with which you want the brace to work. This is not an adjustable brace design.

Lean the brace against the door at approximately 15 degrees. (It can help to visualize 15 degrees as a third of a 45 degree angle.) Note the proper length of the tubing to reach just under the door knob, leaving about a half inch of room for the hammer hook.

Use the pipe cutter to cut the tubing. Place the tubing inside the cutter, tighten down, and spin the cutter 'round the tubing, turning the knob as required to maintain gentle cutting pressure. Don't overtighten the knob and then fight to turn the cutter. After several passes, the tubing will break apart cleanly.

For my door jam, I cut the tubing to 35 3/8 inches long. The total length of my finished door jam is 39 1/2 inches, including the prongs of the hammer hook. The distance from the floor to the bottom curve of my door knob is 34 7/8 inches. There's a bit of leeway in the optimal length of the jam such that I can use this on any door in this house just fine. I wouldn't want it to be more than an inch off either way, to maintain a good wedge angle of 15 degrees or so.

Step 5: Attach the Hammer Hook to the Top of the Tubing

Following the procedure from Step 3, permanently attach the hammer hook to the top of the tubing. While the epoxy is fresh, jam the brace tightly under the intended door knob and leave it there to cure. This will set the angle of the top section of the brace to fit the door well.

Protect the door knob from epoxy mess with some scrap plastic wrap.

There is no gap between the top of the tubing and the bottom of the hook. Just let the hook rest directly on the edges of the opening of the tubing.

Step 6: Put to Use

To install, place the hammer hook around the door knob and gently kick the rubber leveling foot toward the door.

To wedge it in more, turn the door knob and open the door toward you if possible, and then kick the brace again to retighten. Re-turn the knob until it relatches.

To release, simply kick the base away from the door with your foot.

The door jam can "harden" your exterior entrances, secure any room inside the house (in case of home invasions, crazy roommates, or domestic abusers), or ensure that the door will stay shut as you're doing your TRX or resistance band exercises on the "wrong" (that is, openable) side.

Let me know if you have any questions. I'd love to see pictures of your homemade door jams, either this design or a better one!

CREDIT: Much thanks to the unique and wonderful McGuckin Hardware store in Boulder, CO.

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    9 Discussions


    4 years ago on Introduction

    Good idea OP.

    You may want to reinforce the latches on that dog door also, someone that really wants in can kick the dog door in then reach through and remove any locks you have.

    1 reply

    Reply 4 years ago on Introduction

    Very, very good point! What you can't see in the picture is that I've hacked the hollow core door to incorporate an RFID chip scanner and a laser guillotine. Unauthorized intruders won't get more than a head through the door.


    4 years ago

    love making stuff for a fraction of the cost of shop bought version - so satisfying. do you think the door knob might work loose from the door after months of use? wonder if fitting a u shaped piece below or to the side of the knob to receive the fork might be a good adaptation.

    3 replies

    Another thought -- you want the door hinges to be sturdy as well, especially for exterior doors. It doesn't help if they give way instead of the door knob. Without foreknowledge of the door jam, though, most criminals would target the door jamb area for kicks, rams, etc.

    See this excellent Instructable on reinforcing door jambs and hinges.

    Thanks for the comment!

    Yes, the integrity of the door knob is a very good point. You need it to be strong enough to hold up to being wedged over and over (depending on how rough you are using the door jam), and what's more, you don't want the door knob itself breaking off in the event of a meth head trying to ram his way into your house.

    I think the weakest part of the door knob is probably the two bolts that are holding it on the door. I assume a more expensive, exterior rated door knob is going to have better fastening bolts (maybe stainless steel) and generally be more fit for this use than a 50-year-old, economy model, interior door knob.

    You could certainly bolt something extra onto the door to hold the brace, as you suggested. I think that would be a special adaptation, however. I think the jammer on the door knob is a fine solution for most residential purposes.


    4 years ago

    title says solid steel, but the tubing is hollow. did I miss a step? also, to avoid all the epoxy mess couldn't you use a thick dowel rod or piece of hand railing, them just drill holes on either end and screw in hardware??

    2 replies

    Reply 4 years ago

    Solid steel refers to the material, not the tube shape. (Solid copper plumbing pipes are also tube shaped.) I'm not concerned that Metro tubing isn't sturdy enough for this purpose. Its track record of dependability is why I chose it.

    You can certainly use a dowel instead, and that would be faster and easier to make, but wood will always split if you screw something into the end grain and then slam away at it. I guess I'd recommend putting a pipe clamp or something around the end of the dowel to discourage splitting.