Smoke and Carbon Monoxide Alarms

Home Inspection Smoke Detector Solid State

Did you know 30% of smoke alarms in North America are not maintained? Smoke alarms (also called smoke detectors) have been in common use since the late 60’s and in the last few decades have been required in all new home construction and in some cases fire codes have required retro-fitting them into any residential homes. Identifying smoke alarms is a requirement in a home inspection, but how do you know if yours is working?


What is the Difference between a Smoke Alarm and a Carbon Monoxide Alarm?

Both smoke alarms and carbon monoxide (CO) alarms are important life saving devices in your home but they behave in totally different ways.

  • Smoke Alarm - The primary role of a smoke alarm is to detect the early stages of a fire in the home and to alert the occupants while they still have time to safely escape. The health risk of not having a smoke alarm are burns, suffocation by smoke inhalation, both leading, in the worst cases, to death.
  • Carbon Monoxide Alarm - A CO alarm measures the amount of CO gas in the home’s air and alerts occupants when the levels are too high. CO is colourless, odourless and has a cumulative effect on health (meaning you get sicker from longer exposure to even minor amounts). The health risks of not having a CO detector is dizziness, headaches, nausea, and in worst cases convulsions and death.
  • Combination Alarm - This alarm includes both a smoke and CO detector in one device.


Where does Carbon Monoxide come from?

Carbon Monoxide is a common exhaust gas from burning fuels. It is produced in our homes by furnaces, boilers, and hot water tanks as well as gas ovens and cooktops, car exhaust, and gas fireplaces. CO gas spreads evenly in a home so alarms need to be placed on all living levels and particularly near bedrooms.


A professional Home Inspector will inspect venting on utility equipment, fireplaces, and kitchen cooking equipment as well as look for an air tight seal between the house and garage. However, not all CO deficiencies are visible in an inspection and CO can occur at any time due to a system failure. Having a CO detector in your home is an excellent way to protect yourself and your family from this colourless and odorless gas.


Why does my smoke alarm always go off when I’m cooking?

There are two common types of smoke detectors. 

  • Ionization - This type of alarm uses an air ionization process to electrically measure smoke particles in the air. It is reactive to the earliest signs of fires and while this is possibly a nuisance near kitchens due to false alarms from burning toast, it is a benefit near bedrooms when occupants need the most warning of a fire to exit safely.
  • Photoelectric - This type of alarm looks for smoke particles suspended in the air. If you are suffering from false alarms due to cooking, replace the smoke detector with one of these alarms. Some alarms also have a ‘hush’ button to silence false alarms. Never remove the battery from a smoke alarm or you risk not having a working alarm in a real fire.


Where Do I need to Install Smoke and CO Alarms?

Codes for this vary by municipality but smoke alarms should be at minimum on every level of the home and outside of bedrooms. Ideally, they should also be inside every bedroom.


At minimum, a CO detector should be located near bedrooms however the best advice is to have one on every level of the home and in each bedroom. Since best practice is to have both a smoke and CO alarm in all bedrooms, this is well accomplished with a combination smoke/CO alarm in each bedroom.


Landlords and Tenants

As the owner of any residential home, you have a responsibility to provide operating smoke detectors. Tenants should also be responsible for their own safety by making landlords are aware of missing smoke detectors and changing batteries as needed.


If you are a landlord and are not sure if you have smoke detectors in your rental suite, you need to investigate it as it is the law to have them in place. Many home inspectors can inspect for smoke alarms on a rental property if you don’t live in close enough proximity to check yourself. This is also a good opportunity to have the home inspector do a full home inspection and written report to ensure your rental property is well maintained and safe for the tenant.


Batteries and Life Cycle Replacement

30% of smoke alarms installed in residential properties are not maintained correctly and this is largely due to unit age and battery life. 

  • Every 10 Years - The measurement equipment in smoke alarms deteriorates over time and as a result they need to be replaced every 10 years. Units with square 9-volt batteries should have batteries changed annually. A good way to remember this is to do it with the change to daylight savings time. Many newer smoke alarms have integrated 10-year batteries which makes them maintenance free as long as they are replaced every 10 years. Some smoke alarms are hard wired to the home or alarm system so they never need batteries; however, the alarms themselves still need changing every 10 years.
  • Every 7 Years - CO detection equipment lasts only 7 years. These units are most commonly run at power outlets which don’t need batteries changed but there are battery operated units which require batteries changed about every year.


Final Thoughts

No matter if you own a home now, you are a renter of a home, or you are in the process of buying a home, you need to ensure the life safety equipment in your home is operating. Take a moment now to check your home equipment and if anything is missing or needs replacing, look after it today. 


If you are having a home inspection done, your home inspector should be looking for smoke detectors at each level of the home and outside of bedrooms. Unfortunately, home inspectors cannot open alarms to confirm the alarm age or battery quality so always plan to replace batteries on move in day and check the date stamp on the equipment at that time to see if it needs replacement. CO detectors tend to be portable and many occupants take then when they leave. Have new CO detectors for your home with you and install them on move in day.


By James Bell - Owner/Operator of Solid State Inspections Inc.