Tom and Pam Moore thought their house in the hills of north Poway was reasonably protected from wildfires. It had concrete siding, a tile roof, covered eaves, a healthy defensible space around it and a fire hose.
"We built it with all the future requirements" to make it fire-safe, Tom Moore said. It wasn't.
When the Witch Creek fire roared through in October 2007, their 6,800-square-foot house and a large horse barn burned to the ground, along with four other houses in their rural neighborhood.
This time, the Moores are taking no chances. After much research, they are building a house they are convinced will be impervious to fire.
"I started researching the day the house burned down," said Pam Moore, 56, a retired San Diego Unified teacher.
Their new, 4,800-square-foot house, scheduled for completion in December, will be built using virtually no wood - or anything else that is flammable. Although it will be indistinguishable from a typical house, it will be unlike any in the county, say those involved with the construction.
The walls of the partially completed house were made using insulating concrete forms - known as ICF construction. It involves stacking sections made of expanded polystyrene foam, installing rebar inside the sections, and filling them with concrete. The 4-inch-thick layer of foam on each side remains in place as an insulator and is covered with drywall inside and stucco outside.
There are a number of houses in San Diego County built using ICF, but they are relatively rare.
They are more common in the Midwest and on the Gulf Coast, where tornadoes and hurricanes are a threat, said Dean Seibert, chairman of the Insulating Concrete Form Association, a trade group. The association estimates there are more than 1 million ICF houses across the United States.
The roofs and ceilings of nearly all ICF houses are made with wood trusses used in standard construction. But that wasn't good enough for Tom Moore, who is retired from his real estate business and works for a construction company owned by his daughter.
The Moores believe their old house, where they lived for nearly 30 years, burned because the barn caught fire through an open door, and the heat from that blaze ignited wood in the walls of the house. If heat can ignite wood in walls, Tom Moore figured, it could do the same to the wood in the ceiling and roof.
Initially, Moore said he thought he would have to settle for a standard wood-truss roof and ceilings because the structural engineer couldn't design them using concrete.
"There's not a lot of structural engineers who have experience in this stuff," he said.
Then he found Curtis Patterson, of Patterson Engineering in Pacific Beach, who said he could design an all-concrete house.
In addition to fire safety, a reinforced-concrete house has a lots of advantages over"stick-built," Patterson said. They are exceptionally earthquake-and wind-resistant, quiet inside and immune to termites.
"They have enormous thermal value as well," Patterson said."It's like living in an ice chest. Once they get the house to temperature, it will pretty much stay there."
Patterson said he knows of only one other all-concrete house in the county, an unconventional design built into a hillside in Descanso.
The Moores, who are living in a rental house, decided they would go all-concrete. They had Patterson draw up new plans.
The ceilings and sloped roof will use a system made by Lite-Form Technologies of South Sioux City, Neb. ICF Installers of Bonsall, which built the walls, is doing the ceiling work, too. The process also involves interlocking foam forms, but these have deep troughs on one side. The forms are placed on the ceiling, supported from beneath by temporary steel posts. Rebar is installed in the troughs, and then a layer of concrete is poured over the forms.
About 40 truckloads of concrete will be used for his roof alone, Tom Moore said.
The support posts are removed after a month, once the concrete has completely hardened. Unsupported spans of more than 40 feet are possible, Lite-Form Technologies says on its Web site.
The foam forms, which won't support combustion, stay in place. They have nonstructural steel studs embedded in them for attaching drywall.
"It's a European technique brought over to the U.S.," Seibert said.
Jim Lawler, Poway's senior building inspector, said the Moore house hasn't presented any significant inspection issues because it is an engineered system.
"What I do is make sure it meets the manufacturer's and engineer's design," Lawler said.
When finished, the only things that will be capable of burning will be the furnishings inside the house, Tom Moore said,"and we'll have sprinklers to take care of that." For good measure, there are six fire hydrants around the house.
One other hurdle was figuring out how to attach clay tiles to the roof without drilling holes in the concrete and risking a leak. Tom Moore said he discovered a Texas company that makes a spray-on adhesive foam used in hurricane areas.
The house also will feature a 250-foot-long array of solar panels on the 17-acre parcel that Moore predicts will provide all their electricity.
The Moores are hopeful the construction method, recycling of unused foam and solar power will help them get a Platinum designation - the highest designation from the U.S. Green Building Council. The nonprofit group operates a program known as LEED that is used to grade"green" buildings.
Moore estimates his custom house will cost about $350 a square foot, about $12 to $14 more per square foot than an identical house built conventionally. With furnishings, landscaping, a new barn, solar panels, swimming pool and other expenses, the project will cost about $3.5 million, he said, about $120,000 more than a stick-built version.
ICF proponents maintain that concrete is ideal for small houses, too. Although they cost more initially, they contend, the houses more than make up for that in the long run in reduced energy, maintenance and insurance costs.
The biggest roadblock for the industry, Seibert said, is that building contractors are reluctant to change their ways.
"They want to do the safe thing," he said.