Shed Alarm: The 3 Most Reliable Security Systems

Shed Alarm: The 3 Most Reliable Security Systems

Last Updated on August 20, 2022 4 Comments

Shed alarms have come a long way in recent years. Modern kits are wireless, battery powered, remote controlled and even modular.

They couldn't be easier to set up. And they've never been so reasonably priced.

But do you really need one? Will they really protect all that stuff you're keeping in your shed (or garage)?

Personally I think a shed alarm adds a great (and unique) extra layer of security...

Unlike a beefy security bar, they won't stop a thief trying to break into your shed. But I can't think of anything else that's going to give a thief as much of a fright as a 130 DB siren going off in their face if they do get in.

Nothing legal anyway!

Below I review three great alarm systems that will work well in both sheds and garages. But if you're still not convinced shed alarms are useful, lets look at some data first...

Do shed and garage alarms really stop thieves?

How many times have we heard alarms going off and ignored them? Plenty I'd guess. Hopefully this is because we think they're false alarms rather than because we don't care!

But the fact remains: if we ignore them, why would a thief to take any notice of them?

However the research suggests otherwise...

In one study from the University of Carolina, over 60% of convicted burglars said they would look for an alarm before robbing a house and if they found one they'd move on to another target.

And another study (from the University of New Jersey) concluded that residential burglar alarm systems do decrease crime.

Thief breaking into a shed

Alarms do deter thieves!

I couldn't find any academic studies that concentrate on shed or garage alarms specifically, but I think the principal should be the same.

Anecdotally, I have also heard stories of bike thieves fleeing when a garage or shed alarm has been triggered.

So, while for sure: not every neighbor will come running when an alarm goes off, the noise itself will be enough to scare off many thieves. And if it alerts you too, you can do something about it!

For these reasons I think that a shed or garage alarm can be another useful layer of security in a many layered set up.

And besides, (as we'll see) they're so easy to set up and some of them are so cheap these days, that there's no reason not to give them a go.

How to choose a shed or garage alarm system

I'm pretty sure there's a suitable alarm system for every shed (or garage). But to find the right one for your space there's a couple of things you need to think about...

What type of sensor is best for your shed alarm?

The first thing to decide is: how your shed alarm should detect a break in. And this comes down to what sort of sensor it uses. There are 3 main types...

1. Door / Window Frame Contact Shed Alarms

These sensors typically consist of two parts. One part is attached to the shed door (or window). And the other part is attached next to the first but on the frame.

A two part door sensor alarm

Although they're not touching they're close enough to form a magnetic contact between them.

When the door or window is opened, that contact is broken and if the alarm isn't deactivated the siren will go off.

The advantage of this type of shed alarm is that it's a very specific trigger. A door or window is only likely to be opened by a person. So there's no chance of an animal, weather conditions, or other types of disruption setting them off.

The main disadvantage is that they won't go off if the thief comes in through the roof. Or through the wall!

2. Vibration Detecting Shed Alarms

These alarms are triggered by movement in whatever they're attached to. So again, they could be attached to shed doors or widows. But also the roof or walls of your shed.

And if someone tries to break in, the vibrations that they cause will set the alarm off.

You can usually adjust the sensitiveness to avoid bad weather or animals setting the alarm off unnecessarily. But that may take some trial and error. And you obviously don't want to make it too insensitive, as that could result in an undetected break in!

One advantage of these types of alarms is that they're likely to detect a break in before the thief actually gets inside the shed or garage. So the thief might be scared off before they do too much damage.

A vibration triggered shed alarm

A vibration triggered window alarm

And also before they see the treasures you're keeping in your shed (and decide it might be worth coming back later)!

But the difficulty of getting the sensitivity settings right makes me a bit wary about recommending this type of alarm in sheds or garages...

You're likely to make them too sensitive initially and experience lots of false alarms. And then after one false alarm too many, you'll decrease the sensitivity too much and they won't go off when you are actually being robbed! 

So that leaves just one more type...

3. Motion Detecting (PIR) Shed Alarms

Often called PIR (Passive Infa-Red) alarms, these security systems work by detecting movement in their field of view using variations in infa-red body heat.

PIR alarms are probably the most popular type of shed and garage alarm available. But they vary hugely in price. And this is largely based on their intelligence (and therefore reliability)...

The problem with the cheaper shed alarms is that they're unable to distinguish between people and animals. So pets, rodents, birds and even spiders can set them off!

PIR alarms sense movement through infa-red heat

More sophisticated alarms are able to take multiple readings from multiple angles to reduce the chances of mistakes...

These are sometimes called Quad PIR alarms (because they take four readings). However, they're more expensive and not so common in alarm systems that are suitable for sheds and garages.

There are also "pet friendly" PIR alarms. These may be Quad versions with 4 sensors, but also reduced sensitivity. So the lower body heat of dogs and cats etc won't set them off. Again these are less common.

4. What about a combination of different sensors?

Good question! And yes, you an buy alarm systems that contain all the different types of sensors to cover all bases.

These are great because they're modular, so you can buy the essentials and then add different sensors, extra sirens, remote controls etc as and when you need them. 

What sort of alert is best for your shed alarm?

A very loud one!? Well yes, you'd usually want a very loud noise to alert yourself, your neighbors and scare the hell out of the thief.

But there's another alert that's worth considering too...


Sirens should be loud! At least 100 Db. But preferably louder. The more noise your shed alarm makes the bigger the fright it will give the thief. And the more likely they are to flee empty handed.

Phone / Text Message

There are also alarms that will phone you or send you a text message (in addition to an audible siren) if they detect a break in! These are called GSM alarms.

All you need to do is buy a "pay as you go" SIM card (£10 of credit should be sufficient), and pop it into the device. And then enter a list of phone numbers.

A GSM shed alarm

A GSM alarm will ring you

If the alarm system detects a break in it will ring or text the phone numbers you've provided. You are then able to turn the shed alarm off and/or disable further detection via your phone.

Most GSM alarms will give you the option to disable either the alarm or the phone alerts. So the system could alert you via phone without sounding the alarm or vice versa. Or both.

Phone alerts are great if you're on holiday or the shed or garage is some distance from your living and sleeping area.

They are also good if the thief manages to quickly disable the siren, as you will already have the phone message and will be able to take action!

You could also use a GSM alarm in conjunction with a normal alarm. The normal alarm could go off with a siren while the GSM alarm stealthily alerts you to the break in. Then it wouldn't matter if the thief manages to disable the normal alarm.

Other things to look out for in a shed alarm...

Does the shed alarm have a low battery indicator?

If the batteries run out and the alarm doesn't trigger when you're being robbed you're going to be pretty peeved!

Most batteries will only last 12 months, which is not long. So make sure whichever device you choose has some way of notifying you that the batteries are low! 

What's the range of the shed alarm's movement sensor?

If you're looking at a PIR alarm, make sure it's range of view covers the entire space. Sheds are pretty small so you should be OK.

But some garages can be quite spacious. In which case, you might need a garage alarm with multiple sensors.

Are the sensor and the siren separate or part of the same unit?

If the sensor and siren are part of the same unit a thief may have time to disable it or destroy it before it's actually had much time to go off.

Unless you can position the unit out of reach, two separate pieces are better as it enables you to position the siren in a difficult to access area.

Three of the Best Shed Alarms

The great thing about modern alarm systems is that a lot of them are modular. So you can start off with the basics for a really cheap price. And then if you need to you can extra bits...

1. Best Budget Shed Alarm: Tiiwee A1 Starter Kit 

The Tiiwee is a really good example of a modular system. It includes door and window sensors, PIR motion sensors, sirens and remote controls. All of which can be combined in different ways to expand your security system.

Tiiwee A1 Starter Kit alarm system

Tiiwee A1 Starter Kit


1 siren
2 door/window sensors

1 remote control

Optional upgrades:

- outdoor sirens

- motion detectors


- wireless

- modular

- 120 DB siren

- low battery indicator

- no false alarms


- outdoor sirens cost extra

- pet friendly sensors not available

I like the A1 Starter Kit [Amazon] which consists of a siren and two door/window sensors and a remote control.

Because the siren is separate you can position in it away from the sensors in a hard to reach place to prevent any thief from destroying it when it goes off.

The siren is 120 DB which is a good volume for a shed alarm. It will certainly give the thief a fright and as long as your living area isn't too far from the shed, you should be able to hear it inside.

And if your living area is a little further away, you can add second siren in your home, as long as it's within wireless distance. You can also add outdoor sirens [Amazon] to the system if you need to.

Tiiwee outside siren

You can also add a Tiiwee outside siren

Using the remote controls you can disarm the sensors before you come through the door, so you don't have to worry about remembering codes and fiddling with key pads in a mad rush.

The whole system is wireless, so the sensors and siren are easily moved around as you wish. And the units are all pre-matched so set up should be very simple.

Plus very important: there are low battery indicators so you shouldn't get caught out once it's working.

I like these simple door and window shed alarms because there's almost zero chance of false alarms. If the alarm goes off it's because someone has come through your door or window!

Compare this with the cheap PIR systems where various things (pets, rodents, birds, insects etc) can set them off, which can get really annoying.

Of course the good thing about the Tiiwee system is that if you decide that the 2 door sensors aren't enough, you can add indoor or outdoor PIR sensors [Amazon], more advanced, (indoor or outdoor) sirens etc etc.

2. Best High-End Shed Alarm: Yale Alarm Kit

A step up in price, the Yale alarm system [Amazon] is also modular. However it offers a couple of significant advantages over the Tiiwee Kit...

Yale starter kit alarm system

Yale Alarm Kit


1 siren

1 PIR sensor
1 door/window sensors

1 remote control

Optional upgrades:

- pet friendly sensors


- sirens suitable for external use

- pet friendly sensors available
- wireless

- modular

- low battery indicator


- 104 DB siren slightly quieter than Tiiwee
- more expensive

Unlike the default Tiiwee alarms, all the Yale sirens are suitable for external use. So you could mount them on the outside of your house or shed/garage.

Yale pet friendly PIR sensor

Yale "pet friendly" PIR sensor

The biggest advantage of the Yale alarms though is that they're the only system to which you can add "pet friendly" sensors [Amazon].

These ensure that the alarm won't be triggered by an animal that weighs less than 27 kg.

Unfortunately the Tiiwee Kit doesn't offer "pet friendly" PIR sensors yet. In fact the Yale system was the only one I could fund that has them as an option...

So if you want a motion detecting shed alarm but have pets that might get in a position to set an alarm off, definitely go for the Yale with the pet friendly sensors.

Unfortunately the "pet friendly" sensors don't come as part of a kit. So you'll need to either buy a starter kit and then add the pet sensors. Or buy the siren, sensors and remote control separately.

You can also integrate the Yale system with a smoke alarm, a panic button and many more (up to 20) accessories.

On the other hand, the 104 DB siren isn't as loud the Tiiwee's and everything is a fair bit more expensive. So I suppose it depends whether the extra features seem worth it to you.

3. Best Phone Enabled Shed Alarm: UltraPIR GSM

If you're looking for a shed alarm that will ring or message you if it detects a break in, but you don't want to spend a fortune, then the UltraPIR [Amazon] is your best choice.

It's a 3G SIM enabled, battery powered alarm that will phone and send SMS messages to up to three numbers when it's triggered.

UltraPIR GSM shed alarm

UltraPIR GSM Phone Enabled Alarm


1 PIR sensor and siren

1 remote control


- sends SMS or calls when it detects a break in

- 130 Db siren

- silent mode option

- wireless

- low battery indicator


- no add-ons available

It also has a pretty powerful 130 Db siren, which can be set to silent...

So if you leave the alarm off, you'll be notified of the break in but the thief won't know you know! And if you leave the siren on, the thief will get a nasty fright and you'll also be notified, wherever you currently are.

The alarm can be enabled and disabled with the supplied remote control which works from up to 100 m distance. And there is a low battery indicator which is useful because these sort of shed alarms are quite power hungry.

The Yale system can also include a GSM option but it's much more expensive.

So if your shed or garage is far from your living area. Or you're most concerned about robberies while your away (on holiday for example). Then this is the alarm for you [Amazon]!

Wrapping Up

Shed and garage alarms can add a significant extra layer of security to your storage space. They may not prevent a break in attempt from starting.

But there's a very good chance that a thief will scarper as soon as the siren sounds.

And of course you'll hear the siren too, so you'll be able to contact the police or chase off the thief yourself.

For most sheds, I recommend you keep things simple. Magnetic contact sensors on the door and windows, wirelessly connected to a separate siren unit should do the job nicely.

There's much less chance of false alarms with this set up. And it will catch the vast majority of break ins.

The Tiiwee Starter Kit is [Amazon] perfect for this. You get two sensors, a separate 120 DB siren and a remote control for a very reasonable price. And if you want to jazz it up with extra sensors and (indoor or outdoor) sirens later on, it's really straightforward.

If you're determined to get a motion detecting PIR alarm then I highly recommend you avoid the cheaper models. False alarms can be frequent and very annoying.

The Yale Kit [Amazon] is very high quality and you can add "pet friendly" sensors which are essential if you're likely to have animals running round that might trigger the alarm otherwise.

Finally, if you'd like to be alerted to any break in by phone call or text message a SIM enabled GSM shed alarm is what you need. And the UltraPIR [Amazon] is by far the best value unit currently available.

But please don't forget: there are loads of other things you can do to beef up the security of your shed!

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About the author 

Carl Ellis

I've had bikes stolen in London, New York and Barcelona. Yep, I was a serial, international, bike theft victim. In 2015 I decided to stop the rot. And not a single bike's been stolen since! Brakes, yes. Bells, yes. But they're another story. Everything I learn, I document on this website. More about my story. Contact me. LinkedIn.

  • Ha, just realised your name is also Carl so I’d better make it obvious you are not commenting on your own content. I am a different Carl !

  • How bout some alarms that sound off really loud just when a magnetic field is broken, that don’t require one to stay up all night checking their own phones?
    Oh….and how bout having it automatically call the police ITSELF…oh and how bout it being independent of a $150 a month security system (who might…knowing your security system and code no, might take it upon themselves to rob you as they have inside know-ledge?
    And….how bout something in the 20-30 price range, that you can set up in about 10 minutes?
    Got anything like that?


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