The roofing crew was licensed, bonded and insured. The company produced a nice list of references. However, my new roof looks lumpy and uneven.

What went wrong?

The short answer is that neither I nor the roofing company's representative asked the right questions before the job started. The longer answer is we still don't know.

My 25-year-old light gray, three-tab asphalt shingle roof. It had served me well, but it was time to replace it. Simple solution: Put the same thing up again. No muss, no fuss.

Wrong move.

No matter what type of roofing you are considering -- asphalt shingles, wood shake, tile or slate -- there's much more to replacing your roof than just checking out the roofer's credentials.

Sometimes, it's hard to know what questions to ask. People in the industry agree, though, that there are some basic steps every customer should take before considering a new roof.

Before the Estimate

"Don't rush the process," said C.I. Harrison, vice president of H.T. Harrison & Sons Inc., a Rockville company that's been in business since 1908. "A quick decision is not always the best decision," she said.

How do you know you need a new roof? Would repairs tide you over for a few more years?

Widespread leaking or cracked and curled shingles all signal it's time to re-roof. And, if granules of roofing material begin showing up in your gutters in quantity, beware -- much of your roof protection is flowing out the downspouts.

"Before calling for an estimate, know what kind of a roof you have," said Steve Gotschi of Dryhome Roofing & Siding Inc. in Sterling. "How old is it? Are you seeking a replacement or just repairs?"

How much of your roof is visible from the curb? On houses where only the roof's edges show, the quality of shingles and workmanship are much more important than the style or color, but on houses such as Cape Cods and ramblers, where the roof is such a big part of appearance, style and color take on weight.

The Estimate

While you are getting several estimates, remember, you're buying more than shingles. You are paying for the roofer's expertise and workmanship, of course, but you are also buying roof components that are not going to be visible.

Betsy Pond, owner of Pond Roofing Co., a 40-year-old company in Merrifield, said, "Unless proper attention is given to the felt underlayment, ventilation and insulation, you could face major attic and roof problems at a later time. A reputable roofer will make sure that all of these components work together to ensure the life of your roof."

When seeking a roofer, choose one who takes time to discuss your particular needs with you. Never hire someone who does a "drive-by" or phone estimate. Set up a time when you can be on site.

Be wary of roofers who are not busy at the height of the season, said Harrison.

The claim of "I just had a cancellation" may be true, but be concerned if you're the only one waiting.

Find out if the job is going to be subcontracted. Is the person doing the estimate going to be the one on site to oversee the job? "We try to make that mandatory," said Gotschi. "The salesman goes to the site to show the crew his intentions, to point out problems he noticed and to answer any questions the homeowner might have." That individual may not stay on site throughout the job, but should be readily available if problems arise.

Will you be able to communicate with those actually doing the work or is there a language barrier? If you are concerned, make a notation on the contract that one English-speaking worker must be on site at all times.

Bob Sisson, a Maryland home inspector, said that any roof estimate should begin with a look in the attic. Is there water damage or is the decking showing signs of rot? "Moisture and heat are the biggest causes of roof failure," he said. It doesn't make sense to put on new shingles if an underlying problem isn't corrected.

Butch Alban, a roofing materials consultant for the Roof Center Inc. in Alexandria, said the only correct way to get an accurate estimate is by walking the roof, or at least examining it up close. Even steeply sloped roofs can be walked with the right equipment.

Titles and Ratings

Can you avoid problems by choosing an advertised "master roofer"? Not necessarily. Gotschi said that roofers don't have to pass a specific test, the way plumbers and electricians do. You can learn roofing from your grandfather or the guy down the street. Anyone with a truck, ladder and business card can claim to be a roofer. Look for someone with a good track record.

However, many shingle manufacturers do bestow their own designations on roofers who are trained to install their particular brand. For example, a roofer who reaches expertise with CertainTeed Corp.'s training may be credentialed as a "Master Shingle Applicator," while GAF Materials Corp. has a "Master Elite" designation.

If a roofer attaches a special designation to his name, ask who conferred the title and what it signifies. How often is recertification required? Then contact the shingle manufacturer to confirm.

If a roofing company claims to have been "rated No. 1," ask who did the rating and how long ago. Turnover in personnel can effect quality of workmanship, so if the crew did top work five years ago, that may have changed. Alban said it's not unheard for some roofers to coast on long-ago kudos.

Sorting Out the Choices

It's important that you meet with the roofer in person and ask to see samples of the specific materials that will be used on your project. C.I. Harrison said you should ask, "Is this the same as what I have? How is it different?" Also, ask to see another property where the roofer has installed the same style, weight and color shingles you are considering.

It's also important to understand how technology has changed roofing styles and techniques since your existing roof was installed.

In the case of my lumpy roof, I assumed that 25-year asphalt shingles today were the same as the original 25-year-old, three-tab asphalt shingles on the house. (Three-tab shingles are one layer thick and 36 inches long, with two slits, one foot apart. From a distance, one section looks like three smaller shingles.) Even though they were aging, they still lay flat and smooth.

According to Alban, that was because the original shingles were thick and heavy, because they had a high proportion of asphalt. Newer three-tab asphalt shingles have more fiberglass, making them thinner and about 50 pounds lighter per square than older ones. (A "square" equals a 10-foot by 10-foot section.) While more durable, these lighter-weight shingles may contour to any imperfections in the wood decking beneath. Light colored shingles seem to exacerbate the problem.

"The standard 25-year shingle then is the low end now," Harrison said.

Many roofers prefer to use "dimensional" shingles because they are easier to install and they visually minimize any imperfections underneath. These shingles -- also asphalt and fiberglass -- have a three-dimensional quality created by laminating two layers together in a pattern reminiscent of wood shake shingles.

Gotschi noted that the term "architectural" shingles is used interchangeably with "dimensional," but it is also used to refer to one-layer shingles with shadow coloring lines that give them the look of dimensional shingles.

The specific style and brand of shingles to be used on your roof should be written into the contract, along with specifications for underlayment, ice barrier and flashing.

Underlayment is the layer that goes between the decking of the roof and the shingles. "Good roofers will give you options in roof deck protection," Sisson said. Underlayment, commonly referred to as 15- or 30-pound felt, now comes in newer synthetic materials that are lighter and more durable than old-style felt-paper.

You should also receive warranty information before you sign a contract. Does the warranty cover all roofing components? Are repairs prorated? Is labor included? "We send out complete written warranties for all of our manufacturers and contractors," Harrison said.

Work Begins

When you sign the contract, ask when work will be done. Starting and completion dates should be written into the contract.

After the materials are delivered to your house, and before the job begins, examine the bundles and write down the manufacturer's information printed on the wrapping. Make sure what is delivered matches what you agreed to in the contract.

If possible, take photos before, during and after the job. Often you can get good close-ups from upstairs windows. Those photos may come in handy if there are disputes later.

Before final payment is made, ask for a "contractor's affidavit of final release." This is a form that absolves you of responsibility if your roofer does not pay his subcontractors or suppliers.

The bottom line: To avoid surprises and disappointment, Gotschi said, "homeowners need to educate themselves."

Ellen Jacobson, a real estate agent with ERA Teachers Inc. in Herndon, offers another sage piece of advice. "Establish rapport with the workers by offering coffee in the morning or lemonade and cookies on hot days. A little kindness goes a long way."