It happens all the time with siding, cabinets, decking, flooring, almost anything: A homeowner sees a flyer advertising special pricing in a local newspaper and wants to buy the material for a remodeling project himself. “It makes things tough,” says Robert Criner, owner of Criner Construction in Yorktown, Va., “when a homeowner can buy at one of the big boxes for the same price I can.”

Up-front On Profit Criner doesn't hesitate to tell it to his clients straight. He begins by explaining the concept of markup. “This gives us a chance to clarify [for them] how we do business and to emphasize that we're not a cookie-cutter operation,” he says. “Usually our work involves part of a larger project, not just the replacement of a single item. We want everything to tie together.” Criner illustrates the lengths his team will go to, for example, to make sure the new exterior trim matches the existing trim, and describes the steps involved in integrating the siding with the housewrap and flashings so the walls don't leak. Moreover, he doesn't shy away from telling customers that to provide a comprehensive level of service, his company needs to make a profit. At the same time, he educates clients about quality differences between products — what makes one siding choice better than another over time — making the case that his knowledge as a product buyer has tangible value. “Essentially, I explain to them why they should pay more for me to do this job,” he says.

This doesn't always prevent a homeowner from trying to save money in a moment of weakness. “We just had a client come back from The Home Depot saying ‘But they were having a sale that was going to end this weekend,'” Criner says. “I made it clear that [if they bought the materials] I still needed to make a profit and that I'd have to mark up my labor more. I also made it clear that I wouldn't warrant anything that went wrong with these products.”

Get A Warranty Contractors are accustomed to providing a warranty, but in the case of owner-supplied materials it's important that they get one from the homeowner. An owner who supplies materials implicitly warrants that they are fit for their purpose, says Quenda Behler Story, a construction attorney and author of The Contractor's Plain English Legal Guide (www.craftsman-book.com). “That's the best protection you can get,” she says. “The customer is actually giving you the warranty that if a problem arises, it's his problem.” In turn, the contractor provides a warranty on the installation only, Story says. If the owner supplies the siding, but the flashing leaks, it's the contractor's obligation to fix the leaks. But if the siding color fades unevenly, it's not the contractor's responsibility. “[The client] picked it out, so he can deal with it,” Story adds.

Michael Fast, owner of MRF Construction in Tacoma, Wash., makes an extra effort to discourage clients from supplying materials. He explains the simplicity of a one-stop warranty — one that rests on his shoulders alone — and describes in detail the kind of finger-pointing that often arises when something goes wrong with a product he hasn't supplied. “More often than not,” Fast says, “they back down once they understand all that's involved.”