• Realize that the code for much of Minnesota now specifies just one layer of shingles. That means all old materials must be removed to bare wood sheathing before replacing damaged shingles, according to DOLI spokesman James Honerman. To see if you live in the area affected by this code, go to the DOLI website or call the numbers listed previously.
• Limit your down payment. Some contractors want to be paid half of the total before work begins. Consider paying 10 percent down instead. If the company were to fail before your roof was finished, you could lose all or some of your down payment.
• Check your contract for mention of charges for repairs made to the wood on your roof. Often, contractors will quote an open-ended hourly rate for labor plus materials. Depending on the roof's condition, that could add thousands of dollars to the cost. When the shingles are off, you aren't in much of a position to argue. On the other hand, the contractor can't see the condition of wood under the old shingles and wants to avoid underbidding by keeping the woodworking clause open. Ask for a worst-case scenario price (such as for a whole deck replacement), or ask the contractor to set a limit on the price for rotten-wood replacement.
• Ask about quality controls, both in terms of how well the roof is installed and how well your property will be treated. Be sure to get it in writing that the workers on your roof (as well as the company) are insured in the event of injuries, accidents or shoddy workmanship.
• Be part of the project. Contractors say they've had homeowners or neighbors sit and watch the whole job from windows or the lawn. It's not a bad idea to know what's on your roof and how it was put there.