Spontaneous combustion caused the fire that destroyed a Beverly Farms mansion last week.

Rags soaked in painting solvents spontaneously combusted and caused the four-alarm fire last week that destroyed a Beverly Farms mansion the former chairman of the state Republican Party owned.

The distance from the home to available fire hydrants hampered efforts to bring the fire under control.

State Fire Marshal Stephen Coan and Beverly Fire Chief Richard F. Pierce announced the findings on Friday.

Darrell Crate owned the home, at 890 Hale St., and was the only one home at the time of the fire. His wife and four children were not at home when the fire broke out. No one was injured.

The rags were part of a renovation project that was going on in the house at the time of the fire, the Fire Marshal’s office said.

The fire was reported just before 9 p.m. on Aug. 21.

Firefighters from at least eight surrounding communities helped Beverly firefighters at the scene with a combined total of 17 fire trucks and engine companies.

The front wall and three chimneys were about all that was still standing after the fire.

Beverly firefighters stayed at the property through the day on Friday.

Fire Department Capt. Peter O’Connor said firefighters put out hidden pockets of fire that were still burning, some in voids of space created when sections of the house collapsed, preventing water from getting to the fire.

“Crews doused those spots with large volumes of water and in some cases worked to dismantle structural members that were concealing the hidden fire,” O’Connor said.

A four-car detached garage located near the house was saved, O’Connor said, even as many embers flew from the fire.

Last summer, Crate built a new deck, which city permits said cost $245,000. The rags were being used while the deck was stained.

In addition to about $80,000 in interior renovations to the kitchen, basement and bathrooms, Crate had recently applied for a city permit for management of invasive species and to add plantings and construct trails and a fieldstone bridge on his property, according to an Conservation Commission agenda for its meeting next week.

Crate, who served as chairman of the Republican State Committee from 2003 to 2007, is chief financial officer at Affiliated Managers Group, a money-management firm whose headquarters are only about a mile down Hale Street in Prides Crossing.

At first firefighters went inside to fight the fire, but once they learned that everybody was safely out of the house and “the magnitude of the fire was realized,” they fought the fire from outside the building, far enough away in case that walls collapsed outward, said O’Connor.

The roof collapsed as fire engulfed the home.

The home was on seven acres and assessed by the city, for tax purposes, at $3.1 million.

The 15-room, 10,000-square-foot home that was built in 1896 was set back from the street and the flames were visible from the street and firefighters worked to get water from hydrants to the fire, which was at the end of a long, uphill driveway.

Firefighters laid more than 3,500 feet of hose up the main driveway, O’Connor said, which consisted of three separate hose lines to three different hydrants.

From the back of the property off Juniper Street, firefighters laid 1,500 feet of hose up a dirt access road.

“All of the responders worked extremely hard to get sufficient water to the scene,” said Deputy Chief Paul Cotter. “Some of the heavy lines had to be stretched by hand down dirt roads to locations pointed out by (Public Service Director) Mike Collins with his infrastructure expertise.”

In addition to all the firefighters, crews from Northeast Regional Ambulance, Beverly Emergency Management, Beverly Public Services Department and Peabody-based Rehab 5 helped at the scene.

To hear audio of emergency transmission during the fire, go to: www.scanmerrimackvalley.info/files/Beverly-3rd-082108.mp3