Wall art

To hear stonemason Nick O'Hara talk about building fieldstone walls, you'd think he was an art preservationist, not a contractor. When he receives sales calls from Massachusetts farmers who've disassembled their centuries-old stone walls and piled them up to be sold, O'Hara scoffs.

"I tell [them], `I have no interest in that stone, thank you. You've already destroyed it,' " says O'Hara, explaining that piling up stones can break them apart -- and damage the precious lichen that his customers covet. "It's very much a sinful thing to do," he adds. Instead, O'Hara requires handpicked stones that are carefully laid in beds of mulch in the back of dump trucks.

O'Hara, 50, is one of a distinctive group of New England stonemasons who specialize in constructing free-standing "dry" fieldstone walls -- built with round boulders indigenous to Massachusetts and stacked without aid of mortar. The building process can take months to learn and years to master, and requires both artistic sensibility and brute strength.

O'Hara and other masons say these walls are in high demand as the popularity of "hardscapes" -- the presence of stone in landscape designs -- has risen in high-end residential neighborhoods around Boston in the past 20 years.

Long a landmark of the New England countryside, fieldstone walls were once considered piles of junk. Colonial farmers would pick pesky boulders -- mostly igneous rock left by the last receding glaciers over 10,000 years ago -- from their fields during spring plowing, then pile them along the edges as makeshift barriers, according to Steve Mabee, Massachusetts state geologist.

Over time, one century's nuisance became another's nostalgia, and later generations considered the walls reminders of times gone by. These days, says O'Hara, wealthy homeowners pay up to $55 a square foot to have fieldstone walls built along their driveways or gardens, in the same method the Colonial farmers used -- without mortar in the middle.

However, the art of wall-building in Massachusetts has changed in 300 years. O'Hara and company demonstrated their craft recently at a job site in Sudbury, an enormous federal-style antique mansion tucked away in a wooded neighborhood a few miles from Walden Pond. The project manager was a man named Kevin Conway, a 42-year-old Irishman who's been building fieldstone walls since he was 15. Tall and sinewy, Conway seemed more like a soft-spoken sculptor than a construction man. But make no bones about it, Conway said: Wall building demands physical strength.

"That's probably the main requirement," he said. He pointed out a dry fieldstone wall in the woods behind the house, which he estimated was built hundreds of years ago by residents who farmed this land before it went fallow and sprouted into a small forest. The steel-blue stones were covered in moss and lichen, and looked more like a long pile of rubble than a wall. Conway said his crew would disassemble it and rebuild it at the front of the driveway.

When they do, the new wall will match the industry standard: flat sides and few gaps between stones -- like a bunch of stone puzzle pieces locked together and dropped into concrete forms.

Conway described the challenge of making a man-made structure -- comprised of irregularly shaped components -- look natural. The key, he said, is to place the stones in the same way they are found in the woods. "There's a top and a bottom to every stone," Conway explained. When the stones are placed in the same position they would land after rolling down a hill, the wall will be more structurally sound, he said.

Carolyn Sullivan, owner of the Sudbury home, said that she and her husband chose dry fieldstone walls for their property because they wanted to "fit in with the landscape around us." She added that O'Hara & Company is "very talented."

But arguably, the best talent in dry fieldstone wall building comes from Conway's native Great Britain. There, you'll find the Dry Stone Walling Association of Great Britain, a non-profit organization of about 1,200 stone wall builders that, along with working for the preservation of 70,000 miles of stone walls in England alone, holds a series of wall-building competitions every year. Judges rate the "wallers" (as they are called in Great Britain) for craftsmanship, and winners take home small cash prizes.

In Massachusetts, that skill and understanding isn't confined to transplants from Great Britain like Conway. As the hardscapes industry has grown, a number of South American and Central American immigrants have taken up the craft, according to John R. Stilgoe, a professor in the history of landscape development at the Harvard Design School.

One of those is Mario Conceicao, a 51-year-old native Brazilian who started M & M Stone Masonry with a partner in Marlborough two years ago. At a recent job at the Old Sandwich Golf Course in Plymouth, Conceicao said business has been great so far.

"Last year, I made as much money as I did in the 13 years [prior]," said Conceicao, whose gross sales in 2003 were over half a million dollars. He estimates that 90 percent of the walls he builds are made from fieldstones. Conceicao's crew of 15 masons is made up primarily of Brazilians and Guatemalans -- his best masons make around $15 an hour and take six months to train.

But Conceicao, Conway, and O'Hara all agree that dry fieldstone wall building isn't just for the experts. All three said that homeowners shouldn't be scared away from giving it a try -- as long as they have a little patience and a lot of time. For these ambitious beginners, there are free masonry seminars each spring and fall at Plymouth Quarries of Hingham (plymouthquarries.com, 781-335-3686). Taught by stonemason Derek Stearns of Stearns Stoneworks, each four-hour class gives an overview of a variety of the mason trades, including dry fieldstone walls.

"They're the ones that drive people out of their minds," said Stearns, "but they're the ones that everyone wants."

Stearns describes building dry fieldstone walls as "trying to put a bunch of basketballs together." He tells the 20 to 50 homeowners at each seminar they should consider using mortar to make the job easier -- but many prefer to stack dry, like their forebears did.

Some of Stearns's students have built beautiful walls at their homes, he said.

But he gives this word of warning to homeowners: "You need to determine if this is really what you want; if so, then your weekends for the summer will be all taken up."