Wood rot, termites, leaning frames, bowed walls, and weather can all cause problems on a siding job. However, most are at least as easy to avoid as they are to solve, contractors say.

“The best thing you can do is to set the customer's expectations up front,” says Bill Kidd, president of Missouri Siding and Window, in Sibley, Mo. “Everybody expects you to do everything. It is as important to tell [homeowners] what you won't do as it is to say what you will do. If you do that properly, then you usually don't have problems,” he adds.

Shawn Talbot, owner of Forever Siding & Windows, in Belmont, N.H., agrees. “As long as you do a good job sales-wise in the beginning, and people feel that you are treating them right, the jobs tend to move pretty smoothly.”

MAKING ADJUSTMENTS Hidden damage may be the biggest snare for contractors. Talbot warns homeowners that he may encounter rot or other problems when the old siding comes off, and that there may be an additional charge. In general, however, he says that homeowners don't object because they want him to find and deal with such problems.

For Joseph Iuvara, president of Iuvara Siding & Windows, in Haddon Heights, N.J., getting installation started right is the key. “The most important part of siding installation is preparation,” he says. That means adjusting for a wall that is out of square and making the wall flat so he can install the siding properly, he says.

JOINING TOP PANEL TO TRIM One perennial problem with vinyl siding is how to fasten the top panel when trimming to fit removes the nailing hem, explains Steve LaPietra, president of Monmouth Vinyl, in Howell, N.J. Some contractors put caulk in the butt and “hope for the best,” but as the siding expands and contracts, the bond tends to break. Others simply nail the top course, ultimately causing bubbles. “The industry hasn't really provided us an answer,” he says.

LaPietra's simple, effective solution is an aluminum fastener called PermaTab, made by Securing Devices, in Conroe, Texas, www.securingdevices.com. The piece crimps onto the last cut panel of siding and then locks onto the finish trim. “This seems to cure the problem,” LaPietra says. “It's been 100% fail-proof for us.”