Reach a Smoke Alarm in a Cathedral Ceiling With an "Alarm Arm" (version 1)




Introduction: Reach a Smoke Alarm in a Cathedral Ceiling With an "Alarm Arm" (version 1)

If you have a smoke alarm that lives waaay up high, you probably have had this adventure:

  • The alarm starts shrieking or chirping for some attention. Maybe it's a false alarm, so you need to take it outdoors to air out. Maybe its battery is dying. Maybe it craves some other kind of care. Whatever - it's not gonna shut up until you get it down from its lofty perch and give it the hands-on care that it is crying for.
  • Alas, you can't reach the alarm from the floor (photo 1).
  • And you can't even reach it from a chair (photo 2).

So it seems your only path to peace is to: (a) find a long ladder, (b) wrestle it into your room, (c) teeter precariously atop the ladder, while (d) twisting and unplugging the alarm until it's free of its mooring. Then, when you've performed whatever service the smoke alarm needed, you have to do the whole grueling process again, in reverse order.

Here's an alternative: Build yourself an alarm arm. It's a gizmo that spans the gap between you and the smoke alarm, so you can put it up and take it down without your feet ever leaving the floor (photo 3). In addition to the arm, the system requires customizing the fixture that holds the alarm onto the ceiling, so that the arm can take it down and put it back up.

These instructions begin by showing you how you will use your alarm arm (steps 1-2).

If this looks like something you want, steps 3-7 show you how to make one for yourself. It is built out of commercially available parts. You should be able to find all of them at your local hardware store.

This particular design of an alarm arm is not going to work for everybody. Check out step 8, which lists a few of its limitations. I have labeled the present design as "version 1" in the hope that you may be moved to come up with a different and better version 2 or 3 or 4 - and publish your instructions here, of course!

Step 1: Using It: Putting the Smoke Alarm Up

    The video probably is the best tutorial on how to use this thing. But here are some words for your left brain:

    1. Telescope the arm down to its shortest length.
    2. Place the alarm (with its base attached) face down into the carrier (the orange basket in the photos). Make sure the alarm is positioned correctly in the carrier:
      • At the lower edge of the alarm, the rim of the base must be resting on the rim of the carrier.
      • At the upper edge of the alarm, the face of the alarm must be resting on the prongs of the carrier. The prongs must not extend over the top of the alarm. You can bend the prongs as needed to make the positioning correct. Once you get this right you'll never have to adjust it again.
      • If you care about esthetics, you can rotate the alarm in place so that the logo and other features on its face are right-side up (see photo 6).
    3. Holding the arm vertical, telescope it out to its full length. Twist the pole segments to lock them in place.
    4. Raise the arm until the alarm is aligned with the ceiling plate. When you get the alarm close enough, the magnets will lift it out of the carrier and hold it on the ceiling.
    5. If the alarm ends up stuck to the ceiling in a position you don't like - maybe it's off center or not oriented quite right - you can carefully nudge it into a happier position with the carrier.

    Step 2: Using It: Taking the Smoke Alarm Down

    Again, the video should be your best teacher. If not, try this narrative:

    1. Telescope the arm out to full length.
    2. Get the smoke alarm positioned properly in the carrier as described in the previous step. The key to positioning at take-down time is to make sure that, at the lower edge of the alarm, the rim of the mounting plate is be resting on the rim of the carrier.
    3. Gently push the alarm upward along the ceiling, until enough magnets disengage and the alarm is resting in the carrier.
    4. Holding the arm vertical, telescope it down until the smoke alarm is safely in your hands.

    Step 3: Making It: System Components

    This system (in fact, any system that solves this problem) consists of three components, which here will be called:

    1. The smoke alarm. It usually has two sub-components:
      • An alarm unit, which contains all the working parts.
      • A base, which holds the alarm unit in place on the ceiling.
    2. The ceiling fixture. Its job is to hold the smoke alarm in place on the ceiling, in a way that lets you remove and replace it when you need to.
    3. The arm. It's the contraption that enables you to put up and take down the alarm while standing on the floor.
      • A pole, which spans the gap between you and the alarm on the ceiling.
      • A carrier at the top end of the pole. Its jobs are (a) to detach the alarm from the ceiling when you want to bring it down, (b) to carry the alarm down to where you can reach it with your hands, (c) to carry the alarm back up to the ceiling when you want to replace it, and (d) to attach it back in its place on the ceiling.

    How the specific system that I've built implements these components is detailed in the following steps.

    Step 4: Making It: Parts, Prices, and Tools List

    Here are the parts I used to cobble together the three components. I'm being very specific about the brands and models I used, because these are the only ones that I have tried and proven to work together. Also, in case you don't know where to look for your parts, you can Google for these specific products by brand and model. Probably many other parts would work, but make sure before you commit. In particular, the shape and size of the smoke alarm has to fit with the shape and size of the carrier.

    The Smoke Alarm

    1. You must have a fully wireless smoke alarm - one that is powered by batteries and communicates wirelessly with the other alarms (if any) in your system. In other words, your alarm must not be tethered to the ceiling by any wired connections. I used a Kidde model RF-SM-DC ($35). [Important: If you have an interconnected system, where one alarm that detects smoke sets them all shrieking, you must have at least one other alarm in your system that can communicate wirelessly with the wireless alarm you are installing here. In my case, I had to replace one of the other alarms in my hard-wired system with a Kidde model RF-SM-ACDC ($55).]

    The Fixture

    1. Magnets. These are affixed to the back of the smoke alarm base to hold it magnetically onto the ceiling plate. They have to be strong enough to "grab" the timer when the arm gets it near the ceiling plate, but weak enough that the arm can nudge it free of the ceiling plate when you're taking the alarm down. I used four stick-on neodymium "super magnets" from The Magnet Source, model 07528 ($15).
    2. Ceiling plate. A flat metal (not plastic!) plate that can be attached permanently to the ceiling. The magnets on the alarm base will grab onto the ceiling plate to hold the alarm in place. I recommend using an outlet concealer - a round metal plate that is used to cover electrical junction boxes that are no longer in use - as your ceiling plate. I used a Westinghouse model 70065 ($6). It's just the right size, shape, and material for this purpose.
    3. Super glue. If you don't use stick-on magnets or you don't trust the stick-on stickies to stick well enough, use a drop of this to bond the magnets onto the alarm base.

    The Arm

    1. The pole is implemented with a telescoping extension pole long enough to reach, when extended, from your chest level while standing on the floor up to the mounting point of your alarm. Its top end needs to be 1" - 1 1/8" in diameter, so you can fit the carrier onto it. I used an 8' Ettore REA-C-H model 42108 ($33), but many other brands and lengths are available and will work.
    2. The carrier is implemented with a fruit picker basket. The one you get must fit rather precisely with your particular smoke alarm. Mine is a Best Garden Fruit Picker model M3 ($6).


    1. A ladder tall enough to reach your smoke alarm location.
    2. A flat-blade screwdriver.
    3. A Phillips screwdriver.
    4. A drill (in case you have to drill holes in the ceiling or the ceiling plate - see step 5).

    Step 5: Making It: Install the Mounting Plate on the Ceiling.

    You have to do this step teetering at the top of that ladder - for one last time. (The jiggly photos for this step show that I'm not too good at ladder-top photography.) Do this step right, and you can live the rest of your life on terra firma!

    If a smoke alarm is already installed at this location:

    1. Remove the alarm unit.
    2. Remove the base, which usually is held to the ceiling by two screws. Save the screws.
    3. Removing the alarm base will expose either an electrical junction box (if the alarm was hard-wired) or a patch of bare ceiling with a couple of holes in it (if the alarm was a non-wired alarm). If you're lucky, the distance between the two holes in the junction box or the ceiling is the same as the distance between the two pre-drilled holes in the ceiling plate you have acquired. If (like me) you're not lucky, your ceiling plate has the wrong spacing, so you'll have to drill holes with the proper spacing - the excess holes will be invisible when the smoke alarm is in place.
    4. If your old alarm was hard-wired, push the wire that's dangling down back up into the junction box.
    5. Attach the ceiling plate to the ceiling, using the same screws that you removed and saved back in step 2.

    If no smoke alarm is already installed at this location:

    1. Drill two holes in the ceiling, spaced like the holes in your ceiling plate.
    2. Attach the ceiling plate to the ceiling with two screws. Use drywall anchors if needed to get a sturdy enough connection. The ceiling plate will need to support the weight of the smoke alarm plus a certain amount of additional pulling as you tug on the alarm to get it down.

    Step 6: Making It: Attach the Magnets to the Smoke Alarm Base

    1. Plan the arrangement of the magnets on the smoke alarm base. Points to consider:
      • The magnets should be fairly evenly spaced around the edge of the base.
      • The magnets should all be placed within the diameter of the ceiling plate.
      • Notice the location of the screw heads that will be sticking up slightly from the surface of your ceiling plate. Arrange the magnets so that they won't land on the screw heads when you place the alarm in position on the ceiling plate.
    2. Attach the magnets firmly to the alarm base. Use stick-on magnets and/or attach them with super glue.
    3. In the photo you'll see that I cut out a few bits of the mounting plate. I did this because I was worried that those areas of the base might hit the screw heads, preventing the magnets from resting flat on the ceiling plate to get a full grip. I don't know if you will need to do that. I'm not even sure that I needed to do it.

    Step 7: Making It: Attach the Carrier to the Pole

    1. Slip the carrier over the top end of the pole.
    2. Tighten the hose clamp on the carrier until it is firmly attached to the pole.

    You've built it!

    Step 8: Redesigning It: Notes Toward Version 2 and Beyond

    Version 1 of the alarm arm has its limitations:

    1. The fruit-picker that I used as the carrier works well if the smoke alarm is on a ceiling that slants at 45 degrees. The farther the ceiling slant departs from 45 degrees, the worse it will work. For an alarm that is to be mounted on a horizontal ceiling or a vertical wall, you'll need to find something else to serve as the carrier.
    2. As noted earlier, the shape and dimensions of the alarm (including its base) have to fit the shape and dimensions of the carrier fairly precisely. If you have a different smoke alarm, you probably will need to find something else to serve as the carrier.
    3. A better carrier would be one that is more like a hand with fingers that can actively grab the smoke alarm rather than just passively cradling it like the fruit-picker does. But for this you need a pole that will let you open and close the fingers while standing on the floor with the pole fully extended. Some fruit pickers ( and branch trimmers ( enable you to operate the tool at the top of the pole from a handle at the bottom - maybe you can get creative with one of these.

    Version 1 works just fine for me in my situation. So it will be up to somebody else to invent and build new and better versions. If you come up with one, please post your story on Instructables - and/or turn your alarm arm into a commercial product, and become a billionaire!

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      Question 2 years ago on Step 2

      Very clever idea. It may save me if I can get it to work. I've now got all the pieces to try a test with one smoke detector, except for the magnets. The part number stated in the writeup doesn't seem to get me anywhere but the woman at the California office that sells "The Magnet Source" brand sent me a sample. This one is a good size to fit. Should I be concerned about the force holding the magnet onto the plate? My smoke detector weighs just under 0.67 lbs.

      DIY Hacks and How Tos

      Clever idea. Another thing that you could do is glue magnets to the housing to make it easiler to grab and remove.


      Reply 6 years ago

      Yes, that's part of the design (see steps 4 and 6). Can you suggest any way I could edit the instructions to make that clearer?