Information About Mounting Alarms

So to start off, let me say that this is more like an NFPA question, but it’s still a more advanced question in the alarm community. Anyways I finally convinced my parents to let me mount my fire alarm system in my room and around the house. Obviously I already know what I have to do and have the equipment that I need, BUT I have no idea what the standard mounting heights would be. As I know of, this is in NFPA code books, but I can’t really find a way to read one (can’t find one); So, I just needed to ask this question. How would I surface mount my fire alarm panel to my drywall? What height should it be if there’s any? Same goes for N/A’s and initiating devices. How and with what should I mount them and at what height should I mount the pull stations and the notification appliances?

You should consider using a sheet of plywood instead, because that is the most practical solution. Mounting alarms around your house also poses a liability issue.

I second this. The argument about placing alarms in your home vs. the liability and dangers has surfaced on alarm forums too many times to count. MDF and HDF (medium/high density fiber) board is more attractive than plywood and easier to mount stuff too, so I would recommend that.

Agreed, MDF and HDF can make a large mess when cutting and drilling, also if you paint, it will take 3-4 layers of primer to make a good surface for the topcoat.

I think we all second Green’s opinion. (or third, or fourth, or whatever) The problem is, if your house is inspected and it’s found that unlicensed life safety work was done, you could lose insurance coverage for said house. Most hobbyists here (with a few exceptions) have their system on a plywood or composite board, and some have mounted the board on a wall, but in a way that it can be taken down easy with very little damage to drywall. When I had a demo setup a few years ago (I never made any videos with it) it was just my RMS-1T and ZNS on a piece of fiberboard with some heatshrink tubing for impromptu conduit. It worked pretty well, and if I wanted to I could have mounted it to my garage wall.

You are thinking of OSB or particle board. MDF and HDF are both perfectly smooth and neither have a grain or little chips to cover up.

NFPA makes all their codes and standards available for free online (can’t download them with a free account, but can view whatever you want and print pages you want).

Free access NFPA codes and standards

The NFPA 72 has all of the mounting heights.

For pull stations:

17.14.5 The operable part of a manually actuated alarm-

initiating device shall be not less than 42 in. (1.07 m) and not

more than 48 in. (1.22 m) from the finished floor.

For speakers and horns: If ceiling heights allow, and unless otherwise permit-

ted by through, wall-mounted appliances

shall have their tops above the finished floors at heights of not

less than 90 in. (2.29 m) and below the finished ceilings at

distances of not less than 6 in. (150 mm). Ceiling-mounted or recessed appliances shall be per-

mitted. If combination audible/visible appliances are in-

stalled, the location of the installed appliance shall be deter-

mined by the requirements of 18.5.5.

For strobes and speaker strobes/horn strobes:* Wall-mounted appliances shall be mounted such

that the entire lens is not less than 80 in. (2.03 m) and not

greater than 96 in. (2.44 m) above the finished floor or at the

mounting height specified using the performance-based alter-

native of Where low ceiling heights do not permit wallmount-

ing at a minimum of 80 in. (2.03 m), wall mounted visible

appliances shall be mounted within 6 in. (150 mm) of the

ceiling. The room size covered by a strobe of a given value

shall be reduced by twice the difference between the mini-

mum mounting height of 80 in. (2.03 m) and the actual lower

mounting height.* Visible appliances listed for mounting parallel to the

floor shall be permitted to be located on the ceiling or sus-

pended below the ceiling.

So mount pulls 42" from the floor to the bottom of the device, any strobe (or combo) 80" from the floor to the bottom, any speaker or horn 90" from the floor to the bottom of the device and you’ll be fine. Or 6" below the ceiling if the ceiling height doesn’t allow for the above.

The code requires any fire alarm device, regardless of whether it’s required or not, to be fully operational if it’s mounted… so putting these everywhere around your house probably isn’t a great idea. We mount demo panels on like 2-3 foot wide by 4-6 foot tall sheets of plywood on a frame with a base that has casters on it so we can move them around. We put the panel towards the top and mount devices on the bottom or around the sides, works well and would give you a nice woodworking project to do on top of everything else.

Great… So what do you guys recommend me to do now?

Get a 3/4" thick piece (any smaller and back-box screws will poke through) of your choice of wood (MDF, plywood, etc.) in the size you want and mount your alarms to that. It is reasonably safe enough to mount it to the wall and attach a plug to it, since it is easily removed and doesn’t harm the wall that much.

On a somewhat related note, does anyone else here, other than me, unplug their system after testing it for videos and such?

The only time I have my system powered on is when I am testing it for my videos or just for fun, with the exception of the security system component. Sometimes I turn that on during the day, since there isn’t anything to it. It always shows alarms on the trouble monitoring zones for the powered-down panels during this time, however.

(Back to the topic now) So the chances of me even mounting an alarm outside my room door is unlikely or can anybody can steer me to understand what the liability issues may be.

Regarding liability concerns, I recommend reading these topics:

<URL url="Legal to have a hobby system. text=“viewtopic.php?f=3&t=6481”>Legal to have a hobby system.
<URL url="What kind of cable can I use? text=“viewtopic.php?f=4&t=5460”>What kind of cable can I use?
<URL url="Hardwiring Questions text=“viewtopic.php?f=4&t=6011”>Hardwiring Questions

Regarding liability concerns, I recommend reading these topics:

<URL url="Legal to have a hobby system. text=“viewtopic.php?f=3&t=6481”>Legal to have a hobby system.
<URL url="What kind of cable can I use? text=“viewtopic.php?f=4&t=5460”>What kind of cable can I use?
<URL url="Hardwiring Questions text=“viewtopic.php?f=4&t=6011”>Hardwiring Questions]

Good ^ That cleared most of my questions.

Sorry for the double post as I can’t edit my last post.

Now a question that is still in topic. If I where to install a voice evac system in my house with only speakers ,no strobes (more like a PA system), wouldn’t it be safer since theirs no “serious” voltages around the house that may arc and cause a fire (except the panel, one pull ,and smoke but that would be on a board in my room).

The speaker circuit would actually operate at s higher voltage than horn/strobes, at either 25V or 75V. Note that this isn’t the constant voltage because it fluctuates with the sound output, which is what creates the sound via the vibration of the speakers.

You really should keep it limited to the board in your room. Regardless of how “safe” it is, it is still extremely likely (almost certain) that your jurisdiction would view it as an illegal installation. On the board, this is mitigated because it can be easily removed. The problem vanishes entirely if the board isn’t connected to the wall at all, because then it is no longer a fixture, but this usually isn’t practical.

Take this into perspective. What would the difference be between me installing a general PA system (No voice Evac) at my house versus installing a home stereo system? You can’t say that Home stereo systems are only for individual rooms as I know many people who actually have speakers installed around their house, that are wired, for party reasons.

Yes, but home stereo systems are not heavily regulated life-safety devices. Speakers are just for fun and really serve no other purpose than to entertain. Fire alarm systems are trusted to save lives. Just the fact that they are life-safety devices opens up a whole can of worms.

So what you’re saying is that, it doesn’t matter to install speakers around the house for entertainment purposes, but if you try to mock a life safety system there will be issues that will evolve out of it?

both fire alarm and P.A. speakers are high voltage, low current, high impedance. they operate at 70v but pull low current so you can get a lot farther distance out of them and because the speakers have built in transformers you don’t have impedance matching so you can basically stick unlimited speakers on a single run with a relatively small gauge wire. also with the built in transformers you set the wattage taps at the speaker so it’s always at a constant volume.

a home stereo system has 4 or 8 ohm speakers matched to an amplifier that only pushes out a few volts (depending on your volume, making it adjustable. nice thing to have at home!) which works fine because you’re only running the speaker line only a few feet, or maybe 100 feet for surround sound. for outdoor speakers at home you’re normally using powered speakers that have it’s own built in amp to step up the signal.