Fire & Smoke Alarms

A smoke alarm is the cheapest life safety device you will ever fit and the one most likely to be fitted badly. Most homes have alarms. Far fewer have enough of them, in the right places, working. If you are specifying for a rental property, a small business or your own home, the two questions that matter are how many alarms you need and whether they talk to each other.

Why interlinking matters

A standalone alarm only protects the room it is in. That sounds obvious, but it is the single biggest weakness in most domestic installations. A fire starting in a kitchen at two in the morning will set off the kitchen alarm, and behind a closed bedroom door upstairs, nobody hears it in time to act. Interlinked alarms solve this: any alarm that detects smoke triggers every alarm in the property, so the warning reaches people wherever they are.

Wireless interlinking has made this far easier to retrofit than it used to be. Older interlinked systems needed an interconnect wire run between every alarm, which meant lifting floors or chasing ceilings. Modern radio interlinked alarms pair to one another over a licence-exempt band and need no cabling at all, so a whole property can be covered in an afternoon without disturbing the decoration.

Interlinking is now a legal requirement in Scotland, where every home has needed interlinked alarms on each storey since February 2022. England and Wales have no equivalent interlinking requirement, but the Smoke and Carbon Monoxide Alarm Regulations do require landlords to provide working alarms on every storey of a rented property, and interlinking is widely recommended good practice regardless.

Grades and standards

UK domestic alarms are specified against BS 5839-6, which sets out grades based on how the alarm is powered and how the system is built. The distinction that catches people out most often is between Grade F1 and Grade F2. F1 alarms use a sealed, tamper-proof battery that lasts the design life of the unit and cannot be removed. F2 alarms use a replaceable battery. Both are legitimate, but a specification calling for F1 cannot be met with an F2 alarm, and Scotland's requirement is written around sealed battery or mains powered units.

Separately, any smoke alarm sold for domestic use in the UK should be built to BS EN 14604, the standard for smoke alarm devices. Check this before you buy, particularly on lower cost imported units.

What to look for

• Interlink capability and radio band, units must share the same band to pair with each other, so keep a property on one variant
• Battery type and life, sealed or replaceable, and how this affects the grade you can claim
• Hush function, the most effective defence against occupants disabling an alarm after a nuisance activation
• Self-monitoring, low battery and dirty chamber warnings mean faults surface rather than sitting unnoticed
• Sound output, 85 dB at 3 m is the domestic benchmark
• EN 14604 certification, and ask for the declaration of performance if you are buying in volume

Where to put them

As a general rule, fit alarms on every storey, in circulation spaces such as hallways and landings, and in any room where a fire is likely to start or where occupants spend a lot of time. Ceiling mounting in the centre of the room gives the best response. Avoid positions directly above cookers, inside bathrooms, or in the path of steam from a kitchen or shower room, since these are the classic causes of nuisance activations that lead to alarms being disabled. If you want the full siting guidance, BS 5839-6 sets it out in detail, and we are happy to advise on a specific property.

Our range

We stock the HiLook HL-S3E-R8, a wireless interlinking smoke alarm running on the 868 MHz band with an eight year battery life. It suits retrofit work where running interconnect cable is impractical, and covers a typical house or flat comfortably.

We are expanding this range, so if you need heat detectors, carbon monoxide alarms or a larger interlinked system, please get in touch and we will quote against your specification rather than leave you working it out from a product list.