The fire Wednesday that destroyed one house and damaged four others near Crystal Lake burned the cedar shake on most of the houses. Those shingles are more combustible than other types of roofing materials, fire officials say.
Firefighters have said embers from the destroyed house at 3217 Carrington Drive blew onto neighboring houses.
The fire remains under investigation by the Crystal Lake Fire Rescue Department, the McHenry County Sheriff's Office and the Illinois State Fire Marshal's Office.
Crystal Lake Deputy Fire Chief Paul DeRaedt said cedar shake shingles, which can be treated to help prevent fires, are good for running water off a roof, but after a few years of being in the sun, they are more at risk of burning easily.
"It certainly contributed to the spread of the fire from the embers," DeRaedt said.
The house at 3222 Carrington Drive was left uninhabitable after the fire damaged its cedar shake roof, which extended into the attic.
DeRaedt said some of the houses that had roof damage had multiple spots burning.
However, materials used in home construction sometimes make it difficult when it comes to fighting fires.
Firefighters say newer and lighter building materials can hold up a lot of weight, but they also can burn faster.
"It doesn't take long to burn before it fails," McHenry Township Fire Protection Chief Tony Huemann said.
Lightweight floors made out of composite materials and trusses being used in houses have become more common.
"They're very strong and good materials for ... building new homes," Cary Fire Protection District Chief Jeff Macko said. "[However] in a fire, they fail rapidly. Those are some of our biggest issues with new construction. Those are things that shorten the time span a fire department can react to a fire."
Previously, construction included conventional solid wood and solid lumber when putting together houses, Macko said.
Huemann said there is the added challenge of more petroleum-based products in homes.
When fires start, those products burn faster and easier.
"It goes back to the combustible material inside your house ... and creates a hot fire load," Huemann said.
Patrick Mullen, the new chief at the Algonquin-Lake in the Hills Fire Protection District, said homes with large open spaces can lead to fires spreading quicker.
Having separations in a house or building, such as walls or fire doors, buys time for people to escape and to minimize the spread of a fire.
"Separations keep the fire contained so it's smaller when firefighters get there, protects occupants, gives them time to get out," Mullen said.
Mullen said any building material of a combustible nature can light up when it's exposed to fire.
"You address that with separations," Mullen said.
Another challenge in Wednesday's fire was a lack of fire hydrants because it was an unincorporated area. Fire departments have to keep water in tankers ready for those possible calls.
In Cary, the fire district has about 3,000 gallons of water in a tanker, which it sends out for rural fires.
"We do have a lot of water on wheels," Macko said.
No matter where someone lives, and regardless of the construction of a house, there are ways to protect a home.
Huemann said thicker drywall and non-prefabricated trusses would help in slowing down fires. But having smoke detectors or fire alarms on every level of a house, and possibly having them interconnected, would help enhance safety and lead to a quicker response.
On Friday, a fire broke out at a house in Johnsburg with an interconnected fire alarm system. The alarm went off when a fire started and alerted the residents, who were able to use a fire extinguisher to minimize damage, Huemann said.
Also, regularly changing batteries in smoke detectors is a simple thing to do to keep a house safe, Huemann said.