| This article outlines the basic choices and equipment used to alarm an oubuilding.
Introduction
More and more people are keeping relatively valuable, easily re-saleable equipment in sheds and garages. These buildings present an easy opportunity to thieves and as such should be protected by conventional physical security and an alarm system.
There are two basic choices regarding how to configure the alarm system.
- A stand alone system in which all the alarm components are within the protected building.
- A system connected to a new or existing alarm system installed in the inhabited premises.
In the first case, it is essential that mains power is present. Although it is possible to run an alarm system off battery alone; it is certainly not recommended - so if you haven't got mains power to the outbuilding then option 2 will need to be the choice. Another consideration with a stand-alone system is that the signalling method has to be heard in the inhabited building, that is unless you hard-wire a sounder in the inhabited building, but if you are going to have a wired connection from the outbuilding anyway then you might as well use option 2.
There are two choices with Option 2 - hard-wired or wireless. If you can run a cable to the outbuilding, then hard-wired is always the preferred method.
Detectors
Consider the following when choosing the types of detectors for use in outbuildings.
Outbuildings often have poorly fitting doors, insects, dust and small animals present, draughts, extremes of temperature etc. and as such detectors which will lessen the occurrence of false alarms should be chosen. For example heavy duty magnetic contacts should be fitted to badly fitting doors (or better still - fix the door!), and pet friendly or dual technology PIR detectors fitted.
The use of window foil is Another useful protection on outbuildings with windows - this is extremely reliable and provides a visible deterrent.
Vibration detectors can be useful but be aware that wooden sheds can get battered in high winds.
Signalling
The alarm can be signalled locally at the outbuilding (external or internal sounder or both) or at the inhabited building or both.
Hard-wired Stand-alone System
A stand-alone system will simply comprise a simple control panel (e.g. Optima G4) and back-up battery, one or more detectors(e.g. a magnetic door contact and a PIR) and an audible signalling device (e.g. external and internal sounder).
Hard-wired into an existing system
This is by far the preferred method. All the detectors in the outbuilding should be connected to a single zone. The cable required from the outbuilding to the building with the alarm depends on the type and number of devices in the outbuilding.
- 2 cores for tamper
- 2 cores alarm (if more than 1 zone then 2 for each zone)
- 2 cores power (only if powered detectors are used - PIR, vibration etc)
- 2 cores for a simple internal sounder
- 5 cores for an external sounder
Because the cable is low voltage it can run to the outbuilding with minimal protection - small bore water pipe is ideal if you wish to bury it underground. long run aerial cables can be wire supported.
Wireless into an Existing System
If you cannot use either of the two hard-wired solutions then wireless is the only other option. There are two main drawbacks with the wireless solution - the choice of detectors is limited, and the radio signal may be unreliable.
Adding a wireless detector is simply a matter of installing the sensor while ensuring that a good reliable signal is being transmitted/received.
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