Chimney Spark Arrestors and Thatched Properties: What Every Owner Should Know
If your home has a thatched roof and an open fire or wood burning stove, chances are high that you’ve heard the term “spark arrestor.”
Spark arrestors were once highly regarded by many insurance companies; however, opinions regarding their effectiveness have changed drastically over the past few years with some now warning against them in the belief they may in fact contribute to fires or other issues.
Let us explain in detail what a chimney spark arrestor is, why there is a discussion about them in the first place, and the questions that should help you choose whether to install (or even remove) a spark arrestor.
What is a chimney spark arrestor?
A spark arrestor is a metal component, typically made from either steel or aluminium, installed over a chimney pot or flue. Its structure resembles that of an ordinary chimney cap or a bird guard, and often has a double mesh covering.
This mesh serves as protection from any stray sparks, burning ash, embers or other debris that might escape from a chimney, potentially landing onto nearby flammable materials, such as a thatched roof or surrounding trees. At the same time, a spark arrestor does not prevent any smoke or gases escaping from a chimney.
Why would spark arrestors seem like a good thing?
The answer is simple. Thatched roofs are more susceptible to fire than roofs made out of slate or tiles, and sparks generated by an open fire can be a real source of trouble. A spark arrestor will work hard to tray and prevent sparks from falling on the thatched roof.
Another useful feature of spark arresters is that they make sure that no birds get into your chimney and start building their nests there.
But then what caused this shift in opinion against them?
The reason is what could (and does) happen in the absence of thorough maintenance.
Creosote and soot deposits can build up, for a start. Much like the creosote and soot deposits in the flue, these can accumulate in the spark arrestor as well. Without regular cleaning, they themselves can turn into a fire hazard and ignite above the roof.
Also, unlike the flue, which can be accessed from inside by a chimney sweep and cleaned without any difficulty, removing a spark arrestor and cleaning it is a difficult task for many chimney sweeps, who may not even consider it in the first place.
Glowing embers can be kept closer to thatch by the arrestor, too, posing an even greater risk. That is why many insurance companies have gone against spark arrestors and even recommend not using them at all because they may pose a far greater risk than having nothing at all.
Find out more about thatched property insurance
What do insurance companies say about it?
Unfortunately, the answer isn’t the same all round. Some insurers still insist on the installation of a spark arrestor as part of your thatch roof insurance, some will advise against installing them because of their contribution to fires.
Some will fall somewhere in between, allowing the decision to be made by the property owner, provided he/she can prove that it is well-maintained.
Be sure to consult with your insurer before making any decisions either way, since doing otherwise might void your coverage.
Bottom line
Spark arrestors are neither good nor bad, but it all comes down to how well they are looked after. An arrestor in good condition and properly maintained may help reduce risks, but an arrestor that is dirty and poorly looked after is likely to increase risks.
The best way to go is to discuss your case with your insurance company and seek professional advice from a HETAS-qualified technician.