Fires can start in a roof space, and it all comes down to a few significant issues which can be avoided with an annual check of the space itself.
Some causes include poorly insulated downlights, wiring installed or terminated incorrectly, rodents chewing wiring, or pieces of asbestos-based materials lying around.
Let's start with the most common problem inspectors find when inspecting houses for property purchasers: halogen downlights. The Australian Wiring Rules stipulate a minimum clearance for halogen recessed downlights of 200 millimetres between the downlight and structural members, thermal insulation and any other substance unless the luminaire has a suitable fire resistant enclosure.
The most common situation we find is insulation surrounding downlights. It seems insulation installers don’t understand the dangers associated with placing insulation over downlights or within the 200-millimetre clearance requirements. While the danger is not the insulation or downlight catching on fire, it’s the debris that comes in under the eaves that trap itself against the insulation and downlights that create the fire opportunity. Insulation will singe but not burn because it’s treated with a fire retardant, but it can create heat. We have seen many instances of singed insulation - especially loose fill insulation - as it will tend to blow around in the roof space with air movement and then position it self against the downlight.
Secondly, if someone places a cardboard surround around the downlight (not within 200 millimetres), the light will generate enough heat to burn the cardboard. Throw in some leaves trapped in the cardboard surround into the mix, and you now have fuel and a reasonable chance that a fire could occur. While you may say this is unlikely, it can happen as it did to an owner-occupier in a Canberra property only a few years ago.
There are only three options when considering your downlights.
- Fit an aftermarket halogen downlight guard. These are covers or guards that are fire resistant and sit over the downlight to prevent debris or insulation from coming in contact with the heat of the lights. These are quite expensive and hard to fit in a low access roof space.
- Buy fire rated halogen downlight hood kits which have the covers built in.
- Consider fittings that don’t use halogens and run cooler and reduce the risk of fire. LED downlights are now a replacement for halogen downlights, and they only require a 25-millimetre clearance.
Wiring not correctly terminated or joined, or power points that are installed incorrectly are other hidden risks in a roof space. If wiring hasn’t been terminated correctly or is exposed and other trades enter the roof space who are unaware of the risk, an electrocution may occur. Even if a handyman or even a licensed electrician is prepared to carry out work in this manner, you likely do not know what other shortcuts have occurred.
Asbestos-based material in a roof space is another hazard. The photo below shows a piece of broken asbestos-based material in a roof space. The property had an asbestos roof which has been replaced. However, broken pieces remained in the roof space. Unfortunately, this is also a common situation in a subfloor as a result of a renovation. It is a case of careless tradespeople not protecting the occupants and future tradies who may need to access these areas.
Last but not least, there are rodents who love to nibble on our wiring and expose a risk. While this is unlikely to cause a fire if RCDs are installed, there remains a risk if these systems fail or you have an old fuse system installed. The other factor is the damage and the replacement cost of the wiring when the little critters nibble all the way through. So if you hear rodents in your roof or walls, don’t ignore them. Engage a reputable pest manager, find where they are coming into the property, and block them out so it doesn’t become a regular occurrence. They tend to enter roof spaces in the winter looking for the warm comfort of a heated home.
If you are buying a home, have it inspected by a highly respected building inspector who you know will crawl around in a roof space and not just flash a torch from a manhole to find the kind of problems that could potentially cause a fire risk. After moving in, have someone regularly - say every 12 months - take a crawl or look around the roof space.