Even if you hire a top-rated roofer, you’ll want to deal with it smartly.

Determine what you need.

Inspect your roof carefully. Does it need to be entirely replaced, or are some parts newer and in better shape? How do the gutters look? How about the flashings? Does rotted-out plywood or trim need to be replaced? Is your attic properly ventilated? You can get free help from each estimator you consult, since each of them may recommend slightly different remedies. Request estimates on the same work from each company. But also ask them to propose deviations from the basic work plan, the reasons for these deviations, and their effects on the total cost.

Specify in your contract what you want done.

Because estimators’ proposals are often imprecise, add specifics before you sign. For example, for an asphalt composite shingle roof, a good contract will state—

• Exactly which roof areas are to be covered, using pictures or words.
• Type and weight of the new layer of felt applied under new shingles.
• Type of shingles to be used—make, color, shape, wind resistance, and weight.
• Warranty on the shingles. Simple three-tab shingles usually have 30-year warranties; heavier architectural shingles have warranties of 40 years or more. But there’s little evidence that longer warranty periods indicate more durable products.
• Which, if any, flashings are to be replaced, which are to be reused, and what materials are to be used. If you have copper flashings now, most experts recommend leaving them in place. Aluminum flashings, on the other hand, are often replaced because they are frailer than copper and cost less. Specify whether replacements are to be aluminum, copper, or some other material—and what weight they will be. Also specify the width of flashing, to ensure it will protect the slope and angle covered.
• That membrane will be installed at a width of at least two feet along the edges of eaves and three feet wide at valleys to prevent damage from ice dams.
• Whether ventilation is to be added. Proper ventilation of your attic releases the water vapor that rises through your house, reducing the chance of rot. Also, during summer good ventilation of the hot air in your attic can keep your house cooler. Press roofers to explain their recommendations regarding ventilation, since there is debate on this.
• Whether the shingles are to be algae-resistant. Algae can be treated after the fact by washing down the roof with readily available chemicals—but you can avoid all that by installing algae-resistant shingles.
• That the contractor is responsible for a complete cleanup. Request a daily cleanup—so the area won’t become a mess over the course of the job. Poor cleanup is a problem cited again and again by survey respondents.
• That the contractor will haul away all debris; otherwise, you may be stuck with messy piles you have no legal right to force the contractor to remove.
• Whether inexpensive metal drip edges are to be installed at the eaves and the rakes. These prevent water from curling back under the shingle edge to reach the wood.

If you have a different type of roof, make sure your contract is similarly specific. For example, it should specify the grade of shakes or shingles to be used on a wood roof, the make and composition of concrete or synthetic shingles or tiles, the number of layers and type of stone for a built-up roof, the type and weight of metal and paint for a metal roof, and the materials and application techniques for a modified bitumen or single-ply flat roof.

If your job requires a permit and inspection, specify in the contract that the company must secure a permit, and that the work must be inspected and approved before your final payment.

Check with your local building inspection office to determine whether a permit is necessary for your roof work.

Indicate in the contract when work will begin and how long it will take.

You should have the right to get out of a contract and find another roofer if your original contractor proves too slow.

Spell out a fixed price for the work and a formula for covering contingencies.

While you should be able to obtain a binding contract at the estimate price, most companies will insist on provisions for extra charges if they find damaged fascias, sheathing, or structural lumber. Most contracts state that required carpentry will be performed on a “per foot” or “time and materials” basis. Make sure your contract states how charges will be computed, typically per-square-foot or per-linear-foot.

Pay for your work as late as possible; indicate payment schedule in the contract.

Many roofers allow customers to pay nothing until the entire job is completed. Although companies have standard policies on payment scheduling, most will alter them to accommodate customers with good credit standing. In particular, never let your payments get ahead of the completed work, and never pay in full until the job is completed. Press for enough leeway in your payment schedule so that final payment isn’t due until your house experiences stormy weather.

Make sure the contractor carries workers’ compensation and general liability insurance.

Specify in the contract whether subcontractors will be used and, if so, their identities.

Write in the contract: “No subcontractors other than those listed are authorized to do work on homeowner’s premises, contractor is not authorized to give any other subcontractors access to homeowner’s premises, and homeowner is not liable for payment to any other subcontractors.”

Arrange to pay for work only after you receive evidence that subcontractors and suppliers have been paid.

A subcontractor, supplier, or worker may be able to get a lien on your house if the roofer does not pay for labor or materials used. To protect against that possibility, write into your contract: “Prior to each payment, contractor must provide homeowner lien releases covering work to which the payment applies. Each release must state the name of the company or individual making the release, releasing party’s address, materials or services supplied, amount contractor has paid for these supplies or materials, and address of homeowner’s roof; and it must be signed by the releasing party.”

Press for a strong written guarantee.

Shingle manufacturers’ guarantees range from 30 to 50 years. On built-up, modified bitumen, or single-ply flat roofs, warranties range from less than 15 to more than 25 years. Roofers’ guarantees of their workmanship usually run from one to two years, but you may be able to get one for five or 10 years, or even longer.

If you regret signing a contract, move to cancel it.

If a roofer solicited your business at your home, you are free to cancel until midnight of the third day after signing. Put your cancellation letter in writing. It is sufficient to get it in the mail within the three-day cancellation period, but send it via certified mail with return receipt, FedEx, UPS, or some other way that generates a record of the date you sent it and its receipt by the contractor.

Leave a phone number where you can be reached.

Things will go more smoothly if your contractor can reach you quickly should problems arise—e.g., damaged sheathing or an unexpected second layer of old shingles.

Keep records.

Maintain a file that includes the contract and specifications, any contract modifications, invoices, canceled checks, and lien releases from subcontractors and materials suppliers.

If possible, give the roofers access to a toilet, cold drinks, and other amenities.

If you are not satisfied, complain.

First, negotiate directly with your roofing contractor. If that doesn’t work, complain to a local government consumer affairs agency, your state’s contractor licensing board, or the Better Business Bureau.