When it comes to chimney repairs, John Rogers, of Rogers Roofing in Hammond, Ind., uses a simple rule of thumb to find the leak: “Think like a drip.” Imagining himself as liquid in pursuit of gravity allows him to formulate a correct diagnosis of the problem, he says.

There are many kinds of chimney, ranging from classic brick to metal “stovepipe.” But for many roofing companies, chimney repairs stop where the roof and chimney meet, says Peter Valdez , operations manager for Interstate Roofing, Portland, Ore. Most roofers only know roofing, Valdez says, and when they venture into chimney repair, “they may or may not know what's going on.” And, he adds, when you're dealing with the homeowner's prized possession — his home — “a chimney is something that should go straight to the [masonry] professional.”

MOST COMMON REPAIR

That may be true, but the most common chimney repair — replacing the flashing — is well within the expertise of most roofing professionals. Even these relatively simple jobs are moneymakers, contractors say. “It's normal for the consumer with a leaky chimney to call a roofing contractor. Most of the time, with chimney leaks, the roof is in bad shape, too,” Rogers says, pointing out that it's extremely common for chimney leaks to become full-blown re-roofs. The question is, if it's more than repairing/replacing flashing, can you diagnose the chimney problem and fix it?

Gary Kearns, vice president of sales and marketing for Kearns Brothers in Dearborn, Mich., points out that mortar joints deteriorate, brick can become water-saturated and crack, some flashing corrodes in contact with mortar, caps break, and wash collars need replacing. Kearns Brothers operates an entire division devoted to chimney repair. Most chimney repairs, he contends, require a professional mason.

HIGH-MARGIN BUSINESS

If you can get the skilled labor to handle them, however, masonry repairs can be particularly profitable, Kearns says. They involve only labor costs and “a few inexpensive materials,” so gross margins run high.

In fact, serious chimney repairs can cost more than a re-roof. “It can take a day or more just to build the scaffolding for a safe work platform to do the work, and another half-day to take it down,” Kearns adds.

No matter how complex, you must make sure you fix the right problem, Rogers emphasizes. “You have to look at the overall chimney and conduct water tests to be sure,” he says. “The worst thing is replacing the flashing and finding that the homeowner still has a leak.” —Jay Holtzman is a freelance writer based in Jamestown, R.I.