Introduction 

"Well, at least we've got a roof over our heads." 

Yes, there's nothing more basic than the shelter a roof provides. It keeps the rain out and the heat and air conditioning in. 

Fortunately, roofs are quite durable and will protect you from the elements for a long time before needing replacement. But eventually work will be needed. When it is, the cost will likely be steep. And unless you make your roof purchase carefully, you may spend thousands of dollars more than necessary and get less-than-satisfactory results. 

These are just a few of the hundreds of roofing horror stories we have heard from our subscribers— 

"Absolutely terrible. New roof leaked after a year and a half. Took NINE months for them to finally deal with problem. Would always claim they would call back tomorrow. NEVER did." 

"Claimed we needed to replace a roof that did not and had never leaked. Seemed like a con job." 

"The final bill ended up several times higher than the initial estimate... Less than a year after the completion of the service, rain water dripped through the ceiling into one of the bedrooms in the middle of the night... They didn't return our messages for several days. After we finally got hold of them and they were scheduled to come and inspect the damage, they did not show up. When they finally did inspect the damage, we were told that they had not used the correct material when they performed the service the first time...that we would have to pay the difference in cost of material this time despite...warranty." 

"Gave them one-third down when signing the contract. A BIG mistake. After three months of delays, they increased the price by 30 percent..." 

"They were two months late getting started and I had a lien placed on my property by the shingle supplier because they didn't pay them on time. They were very rude...." 

"The first big rainfall we had, my roof leaked. I called them several times to make repairs, they put me off over and over again, and never came to make repairs..." 

Even when things don't go horribly, there are all too many minor annoyances—months of waiting (with pots catching drips) for contracted work to begin, work having to be redone, uneven rows of shingles, poor clean-up of nails and debris, and damaged landscaping, for example. 

The key to success is to find a good roofing contractor, agree in writing on exactly what will be done, and keep a close eye on the job as it progresses. Although the roofing business is one where costly mistakes are too common, fortunately, there are many excellent roofers in the area—and the highest rated companies are as likely as any to do your work at a low price. 

We'll discuss how to choose a roofer, how to deal with the roofer you select, and steps some homeowners may be able to take to avoid or delay the need for expensive roofing work. 

Finding a Reliable Roofer 

Our Ratings Tables give ratings of local roofing contractors. The table shows which areas the contractors serve and which of the major types of roofs each company works on. 

Ratings from Customers 

The way most consumers select a roofer or other home-improvement contractor is by asking friends or neighbors for recommendations. Unfortunately, getting a few recommendations is not a sufficient basis for a reliable judgment. Almost all service companies do satisfactory work some of the time, but you don't want to be among the one-in-five unlucky ones. You want to know about the companies that do very good work consistently. The ratings from our surveys of CHECKBOOK and Consumer Reports subscribers, shown on our Ratings Tables are a way for you to check with over 2,000 of your neighbors for their opinions on area roofers. (For more information on our customer survey and other research methods, click here.) And these ratings are not subject to the kind of manipulation by the companies themselves that is all-too-common with the comments often found on the Internet. 

A number of the roofing outfits on our Ratings Tables were reviewed very favorably by a high percentage of their customers. At the time of our last full, published article, thirty-eight of the companies were rated "adequate" or "superior" overall by 95 percent or more of their surveyed customers; 27 were actually rated "superior" overall by 90 percent or more of their surveyed customers. Unfortunately, however, substantial numbers of the customers of some of the outfits listed on our Ratings Tables regretted their choices: 15 of the companies were rated "inferior" overall by at least 15 percent of their surveyed customers. 

Complaint Histories 

On our Ratings Tables, for firms that were evaluated in our last full, published article, we show counts of complaints we gathered from local Better Business Bureaus (BBB) for a recent three-year period. Where we were able to, we have also reported on our ,Ratings Tables a complaint rate for each company, calculated by dividing the number of complaints by our measure of the number of full-time-equivalent employees who perform residential work for the companies. These complaint rates are intended as a rough way to take into account volume of work and the fact that companies that do more work are exposed to a greater risk of incurring complaints. 

You can check current BBB complaint information on any company by contacting the BBB where the company is located (see below for contact information). On our Ratings Tables, in the details under our listing for the company, click a link to the local BBB to go directly to the BBB's most up-to-date report on any complaints about the company. 

Payment Policies 

One way to cut the risk of being dissatisfied is to arrange to pay for most or all of the work only after the job is completed. In California, a roofer cannot require a downpayment of more than the lesser of 10 percent or $1,000. But home-improvement contracts can still require that larger portions of the contract be paid once work begins. Holding back additional payments—or all payments—until work is completed gives you leverage to ensure that work is done properly and on time. Our Ratings Tables show what percentage of the contract price on a $5,000 roof installation job each company "ordinarily" allows the customer to pay at completion or later. About one-half of the companies allow you to hold back the entire amount until completion, but some require that at least half be paid earlier. 

Licenses and Bonds 

It's well to think in advance about additional leverage you'll have if you are not satisfied with a contractor's performance. A company may seem conscientious and cooperative now but prove to be a bit harder to live with later. 

By choosing a contractor that is licensed, you ensure that licensing authorities will have the threat of license cancellation as one form of leverage in working to resolve a dispute. You also enhance the chances that the authorities will feel you deserve their help—because you have taken the care to choose a licensed contractor. Ask any contractor you are seriously considering for proof of a currently valid license; then verify by calling the Contractors State License Board (CSLB) at 800-321-2752 or by checking CSLB's website at www.cslb.ca.gov. In California, any roofing job costing $500 or more must be performed by a licensed contractor. 

An additional advantage of dealing with a licensed contractor is that if it fails to perform under your contract, you will be able to seek compensation through CSLB's complaint process. One of the conditions for being granted a license is that the company must maintain a bond of $12,500. If the Board's inspectors find that a customer is due money back from a roofing contractor, the contractor can be ordered to pay; if the contractor fails to do so, its license can be suspended or revoked and the customer is allowed to make a claim against the bonding company. 

There is a statute of limitations on complaints to the Board: four years from the time of the work in the case of patent defects (flaws that are easily discoverable) and ten years in the case of latent defects (those that are not readily discoverable). You generally must file your complaint within these times in order for the Board to be able to take action on your behalf. But if a contractor provides you with a workmanship warranty for a period longer than the time specified in the statute of limitations, you can press your claim through the Board for the full period of the warranty. 

A $12,500 bond will be enough to cover the costs of most individual roofing jobs. But if a company goes bankrupt, there are likely to be other claims, and the bonding company's total liability is limited to the amount of the bond. Wages of the company's workers will be paid first; then the bonding company will divide the remaining funds among all claimants, pro-rated according to the amount of their claims. 

Proof of Insurance 

If a third party is injured by a contractor working on your home, or if one of the contractor's employees is injured, you might be liable. The best protection is to be sure the contractor has liability and workers' compensation insurance. Before signing a contract, require that the contractor show you current "certificates of insurance" for both liability and workers' compensation. Insurance companies readily issue such certificates. Alternatively, ask the contractor to provide you with contact information for its insurance agent so you can verify that the contractor's insurance policies are up-to-date. 

Financial Soundness and Stability 

You want to be sure your roofer will be around to finish the job and that you won't be left fending off the company's creditors that wish to place a lien on your house. 

A good way to assess financial soundness is to get—and check—references. Ask for the names of major materials suppliers. Then ask suppliers how much credit is commonly extended and what the contractor's recent payment performance has been. 

You can also drive by to take a look at the contractor's place of business and you can check how long the company has been in operation. An easy way to check back a few years is to look at an old phone book. (We recommend keeping an old phone book so you'll be able to check on various types of companies you might use.) Or you can check with the Better Business Bureau. 

If your roof has been damaged in a storm, be wary of contractors who appear out of nowhere and offer to help. There are scads of roofers who make their livings chasing storms—traveling from area to area in search of easy-to-obtain business. Some of these companies do good work. But many do not, and if your newly repaired roof begins to leak a year or two later, you might find it hard to track down the out-of-area contractor. 

Warranties 

You may get two types of warranties on roofing work: a warranty on materials from the manufacturer and a warranty on workmanship from the roofer. Many manufacturers also offer extended warranty protection. 

The materials warranties offered by the major shingles manufacturers are very similar. Asphalt composite shingle manufacturers, for example, agree to pay for the cost, including labor, of repair or replacement of shingles proven to be "defective." The duration of the warranty varies with the quality of shingles you buy. A manufacturer's warranty generally begins with a specified period of time (for instance, five years) during which the warranty covers the entire cost of replacing defective shingles. After that initial period, the manufacturer's exposure is reduced on a pro-rata basis each year for the remainder of the warranty's duration. 

Roofers' warranties of their labor are often much less well spelled out. Some simply say "labor guaranteed for X year(s)." Others say "guaranteed against defects in workmanship for X year(s)." It's not clear whether these statements mean that you will recover costs or have work redone for free only if you can prove that the work was done improperly, or whether it is enough merely to show that the roof leaks. It's also unclear whether, if the workmanship is defective, the contractor must provide only labor, or must also provide required materials. 

You'll be better protected if you find a roofer that will let you write into your contract in addition to all other warranties: "If roof leaks within X year(s), except as a result of accidental damage, contractor will bear the cost of labor and materials to eliminate all leaks." 

Roofers' warranties most often run for one to two years, but some are for five years or more. Most have different warranties for different types of roofs, and shorter warranties for repair jobs than for roof replacements. 

To supplement roofers' warranties—and to protect against roofers going out of business and not being around to honor their warranties—most manufacturers now offer extended warranties that cover workmanship. To buy one of these warranties, you have to use a contractor that has been approved by the writer of the warranty, which usually involves a check on proper licensure and insurance coverage. Also, the warranty seller will require that the roof be installed according to proper specifications (adequate ventilation, premium felt paper, extra protection at locations of likely leaks, etc.). 

Extended warranties usually cost $4 to $10 per 100 square feet of the roof, depending on the length of the warranty. If your roof measures 2,500 square feet, and a typical, 20-year extended warranty costs $10 per 100 square feet, you'd pay $250 extra for it. As with most other extended warranties, CHECKBOOK is skeptical that the value of these manufacturer-offered warranties justifies the cost, but they do represent an additional form of protection.  

Prices 

The quality of a roofer's work and its financial responsibility should be your primary considerations. No price is a bargain price for a roof that leaks or looks unattractive or that is simply never installed. But once you have identified roofers that measure up on these quality factors, price becomes critical. 

You will want to have roofing work done on a fixed-price basis, following an estimate. 

We worked with a few subscribers to get bids on roofing jobs for their homes. So much as possible, each subscriber had all the roofers bidding on his or her home bid on the same specifications. The roofer-to-roofer price differences on the same job were striking. 

Table 1 gives examples of different roofers' bids for several of these subscribers' jobs. For one of the jobs, prices ranged from $4,495 to $13,344—a difference of more than $8,500. For another job, the roofers' price quotes ranged from $6,600 to $12,950—a difference of more than $6,000. 

The message is obvious: get several bids. 

Get your bids from companies that rate high for quality. Our experience with roofing bids over the years has revealed very little pattern: contractors, including high-quality contractors, may have high prices on some jobs and low prices on others. There is not much price-quality relationship. 

We can't give you a firm rule as to exactly how many bids you should get. There is no way to know in advance whether the next bid will be lower than others—a second bid might save you thousands of dollars or might be higher than the first bid and thus save you nothing. Likewise with the third bid. 

Figure 1 illustrates expected savings from getting additional bids based on tests we have done getting multiple bids to replace an average-size asphalt composite shingle roof. 

The likely gain by increasing from two bids to three bids is, of course, smaller than the expected gain by increasing from one to two bids. Increasing from three bids to four bids can be expected to be even less productive. Naturally, the shape of a curve like the one in Figure 1 would be different for different jobs. But for many jobs, the likely savings from getting three, four, or more bids will readily justify the time required. 

Figure 1—How Much a Typical Consumer Might Expect to Save By Getting More than One Bid on a Re-roofing Job

Here are a few guidelines on getting bids: 

• Invite out more companies than you really care to see. Some won't show up for months, if ever. When you've seen enough, simply call the remaining contractors and cancel. During some periods, especially after a roof-damaging storm, you may have to invite many contractors to get even a few to appear. 
• Use estimators as your consultants. When getting your first few bids, you probably won't know exactly what work is needed. So ask each contractor for its suggestions and the reasons behind them; then weigh the arguments and settle on your own set of specifications. 
• Once you have a tight description of your specifications, call back the contractors that have already bid on your job and ask them to adjust their bids accordingly, and give a copy of the specifications to any additional companies you wish to have bid. 
• You probably don't have to be there to meet with estimators unless you need to point out water damage occurring inside your house. If you won't be meeting with estimators in person, make sure to leave copies of your specifications. 
• Get more bids on larger jobs. If you can save 20 percent on a $10,000 job, that's $2,000, but a 20-percent saving on a $500 job is just $100. 
• Get more bids if the difference between the first two or three bids is large. 
• Get more bids on jobs where labor, rather than materials, makes up a large portion of costs. Contractors pay roughly the same amount for materials, but they may differ significantly in what they charge per hour for labor and in how much their workers can accomplish per hour. 
• Get more bids if it's easy—for example, if you'll be home anyway or if you can arrange for the roofer to see the job without you there. 

For small repair jobs, some contractors work on a time-and-materials basis. Avoid this arrangement, if possible; you're much safer with a fixed-price contract. But if you must pay by the hour, check the hourly labor rate, how many workers are included in the rate, the minimum charge, whether you'll be charged for travel time, and how partial hours are rounded. You'll find getting this information is like pulling teeth. 

Working with Your Roofer 

It's not enough to choose a good roofer. To get the roof you want, when you want it, at the best possible price, you must also deal with contractors carefully. 

Be sure you know what you need. 

Inspect your roof carefully. Does it all need to be replaced or are parts of it newer, in better shape? Are the gutters in good shape? How about the flashings? Is there rot in the fascias or sheathing? Is your attic properly ventilated? You can get free help from each estimator you talk with; each may point to slightly different remedies. To make your shopping meaningful, you will want estimates on about the same work from each company, but you will also want to ask for their proposed variances from the basic work plan, the reasons for these variances, and the effects of the variances on cost. 

Figure 2—Parts of a Roof
Familiarize yourself with the language of roofing. This figure will help.  

Specify in your contract exactly what you want done. 

The proposals estimators give you will often be imprecise. Simply add your own specifics before you sign. For example, for an asphalt composite shingle roof— 

• Specify, by picture or words, exactly what roof areas are to be covered. 
• Indicate whether or not old shingles are to be removed. The reasons for removing old shingles before applying new ones are, first, that additional layers may overload underlying sheathing and structural lumber—especially if you will be getting new heavy-weight architectural shingles—and, second, that old shingles can become warped as they dry out and age, causing new shingles to appear uneven. For these reasons, most of the local codes prohibit application of more than two layers of shingles except in unusual circumstances, and roofing over old shingles is less common than it once was because most manufacturers' warranties won't cover shingles laid over old ones. On the other hand, it costs less to roof over than to remove old shingles before re-roofing. 
• If shingles are to be removed, indicate that a new layer of felt is to be applied under the shingles as required by local codes. Also indicate the type and weight of the felt. 
• Specify the types of shingles to be used—their make, color, shape, wind resistance, and weight. Light colors tend to absorb less heat from the sun and may therefore last longer, but there's no hard evidence on how much longevity you gain, and dark may look better on your house. Instead of the simple, flat, three-tab shingles that were the roofing staple for decades, many homeowners are now selecting "architectural," or "dimensional," shingles. These shingles are layered, cut, and colored to give more depth and shadow lines and to look more like slate or wood shingles or shakes. You will want to see an actual sample of the specific make, color, and style of shingle that the contract specifies. 
• Specify the warranty on the shingles. Using shingles with a 30-year warranty rather than a 20-year warranty might cost you a little extra but might spare you or the next owner from facing the cost of labor and materials for roof work for an extended time—although we have been unable to find scientific evidence that 30-year shingles will really last significantly longer than 20-year shingles. Architectural shingles are generally heavier than simple, three-tab shingles, and often have warranties of 40 years or more. 
• Indicate which, if any, flashings are to be replaced, which are simply to be reused, and what materials are to be used. Unless the contract says so specifically, a roofer is not legally required to repair or replace flashings. If you have copper flashings now, most experts recommend that you leave them. Aluminum flashings, on the other hand, are often replaced since they are frailer than copper and cost less. Be sure to specify whether replacements are to be aluminum, copper, or some other material—and what weight they will be. If flashings are to be copper, insist on at least 16-ounce (per square foot) material, and try to get 20-ounce material for valleys. If flashings will be aluminum, insist on at least 0.032-inch thickness. The heavier the flashings, the less the chance that they will be damaged on installation or will erode away, and the greater the possibility that they will be reusable in the future. You'll also want to specify what width of flashing is to be used to ensure it will protect the slope and angle covered. 
• Specify whether any ventilation is to be added. Proper ventilation of your attic allows the water vapor that rises through your house to be released, reducing the chance of rot. Also, in the summertime, good ventilation of hot air from your attic might keep your house cooler. You'll want to press roofers to explain their recommendations regarding ventilation. There is debate in the industry as to how much ventilation is desirable. Local building codes specify minimum ventilation requirements. The best approach usually is to put vents in both ridges and soffits. A good system will include vents that will allow cold air in under the entire roof and good insulation above ceilings to keep warm air in the house from entering any space immediately beneath the roof. 
• Specify whether the shingles are to be algae-resistant. Growth of algae, especially in damp and shady areas, can be an eyesore. Shingles can be manufactured incorporating tiny flecks of zinc or other materials that retard algae growth. Algae can be treated after the fact by washing down the roof with readily available chemicals—but choice of resistant shingles can help you avoid having to do that. 
• Specify that the contractor is responsible for a complete cleanup. Remember that nails and cuttings of flashings will be hard for you to clean up and can be a hazard. Many contractors use magnetic devices to pick up metal. You may want to require a daily cleanup—so the area won't be a mess for the period of the work, and so you can see early on how well the roofer cleans and be prepared, if necessary, to supervise carefully. Poor cleanup is a problem cited again and again by subscribers we survey. 
• Write in a requirement that the contractor will haul away all debris; otherwise, you may be stuck with messy piles and no legal right to make the contractor remove them. It costs a contractor about $100 to haul away shingles removed from an average-size roof. 
• Indicate whether metal drip edges are to be installed at the eaves and the rakes. These edges, which prevent water from curling back under the shingle edge to reach the wood, are generally a good investment, at about $1 to $2 per linear foot. 

Be similarly specific on other types of roofs. For example, say what grade of shakes or shingles is to be used on a wood roof, the exact make and composition of concrete or synthetic shingles or tiles, how many layers and what kind of stone is to go on a built-up roof, what type and weight of metal and paint are to be used on a metal roof, and what materials and application techniques are to be used on a modified bitumen or single-ply flat roof. 

Determine if your roof work requires a permit and inspection; if so, specify in the contract that the company must secure a permit and that the work must be inspected and approved before 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 is to begin and how long it is to take. 

Given frequent customer dissatisfaction with delays (as reflected in our customer survey findings), you will want to 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 to be done and the formula for covering any contingencies. 

You should be able to get a binding contract at the price your company gave you in its estimate. Most companies, however, will insist on a loophole for the possibility that they will find damaged fascias, sheathing, or structural lumber. Most of the contracts we have collected simply stated that the required carpentry would be done on a "per foot" or a "time and materials" basis. You should be sure your contract states how charges will be figured. Typical is a charge per square foot, or per linear foot. 

Seek to pay for your work as late as you can, and indicate in the contract what the schedule of payments is to be. 

About half of the roofers we surveyed will allow you to pay nothing until your entire job is completed. Although companies have their standard policies on payment scheduling, most will bend to accommodate a customer with good credit standing. In particular, never let your payments get ahead of the completed work or pay in full until the job is completed. Press for enough leeway in your payment schedule so that your house is likely to have to face some stormy weather before final payment is due. 

Be sure that the contractor carries workers' compensation and general liability insurance. 

Before you sign a contract, ask to see certificates of insurance. If the insurance documentation is not available at the time you wish to sign, you can write into the contract: "Contractor is required to provide homeowner with certificates of workers' compensation insurance and personal liability and property damage insurance. Work is not to commence, and no payments are required, before such certificates are provided." In addition, it's a good idea to write in a statement that you "will be held harmless for any damages which would be covered by general liability or workers' compensation insurance." 

Specify in the contract whether any subcontractors will be used and, if so, who they will be. 

Say 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 have 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, you can 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, the releasing party's address, the materials or services supplied, the amount the contractor has paid for these supplies or materials, and the address of homeowner's roof, and must be signed by the releasing party." 

Press for a strong written guarantee. 

On asphalt composite shingle roofs, manufacturers' guarantees ranging from 20 years to 50 years are available. On built-up, modified bitumen, or single-ply flat roofs, available manufacturer warranties range from less than 15 years to more than 25 years. Roofers' guarantees of their workmanship usually run from one to five years, but you may be able to get one for seven or 10 years or even longer. 

If after signing a contract you wish you hadn't, 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. Be sure to 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 gives you a record of the date you sent it and its receipt by the contractor. 

If possible, be at home some of the time when the work is being done. 

If you are, you can catch early any misunderstandings about the materials to be used, and you can spot any gross flaws in workmanship. (See examples below.) 

Leave a number where you can be reached. 

Things will go more smoothly if your contractor can quickly reach you when problems arise—such as problems with damaged sheathing or an unexpected second layer of old shingles. 

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

Keep records. 

Keep a file with your contract and specifications, any contract modifications, invoices, canceled checks, and lien releases from subcontractors and materials suppliers. 

If you are not satisfied with your roofer's work, complain. 

First negotiate directly with your roofing contractor. If that doesn't work, complain to a complaint-handling agency. 

What You Can Do Yourself 

You can save money by inspecting your roof regularly to spot incipient problems. And you can save by making simple repairs yourself. 

Be Careful 

You won't save money, however, if you injure yourself or damage your roof as you work on it. A few tips— 

• If your roof is steep or made of wood or slate, stay off it altogether. There's just too much risk of a fall or damaging the roof by breaking shingles. 
• Even if it's safe to walk on, stay off your roof as much as possible. It is easy to crack shingles or pull out nails, particularly if shingles are warped. Much of the repair work done by roofers takes place shortly after new TV antennas or satellite dishes have been installed or removed. Some disreputable roofers in fact have turned the damages from careless roof-walking to their advantage: they come out for a minor repair, or offer a free inspection, and advise that a complete re-roofing job will soon be in order. By walking on the roof roughly, they ensure that their prophecies are soon fulfilled. 
• If your roof is safe to walk on, use soft, rubber-soled shoes like tennis shoes. These are best both for the roof and for your own safety. 
• Don't work on the roof in wet or windy weather. A wet roof or ladder can be dangerously slippery, and a wind can easily knock you off balance. Be sure you don't have wet grass or mud on your shoes. 
• Watch out not to put your weight on loose shingles or on weak spots that you might put a foot through. 
• Be careful that neither you nor your ladder touches power lines. 
• Lift your ladder carefully, and position it properly. Put the bottom end against the house; from the top end walk toward the house lifting the ladder over your head until you reach the house and the ladder is upright; then move the bottom end away from the house about one-fourth of the ladder's length. So that you can more easily step off of and onto the ladder, the top of the ladder should extend at least three feet above the edge of the roof. Climb the ladder by stepping onto the center of each rung and using both hands on the sides of the ladder. Tie off the ladder to the gutter to reduce the risk of its being blown over. 
• When replacing damaged shingles, be sure that the newly installed shingles lay flat over older ones. Also, try not to over-bend existing shingles that do not need to be replaced. If you bend shingles too much, they'll crack or split, and you will have to replace them also. 

Be Vigilant 

It's a good idea to inspect your roof at least annually and after a major storm, even if you haven't noticed leaks. 

If you have an unfinished attic or crawl space, you can do the most important work from the inside. Look for any evidence that water has come into contact with the rafters or sheathing. Poke at dark spots to see if they are rotten. Be sure to look carefully around areas where vent pipes, chimneys, skylights, or other elements pass through the roof. If you spot a hole in the roof, jam a length of wire up through so you'll be able to find the hole from the outside. 

If you have a finished attic, your task is more difficult. You can look for signs of water damage on the ceiling and walls, but the location of such damage may be far from the leak that causes it. Water often passes through a leak and runs along rafters, only dropping off when it hits an irregularity or obstruction. Problems you can't locate from the inside have to be spotted by out-of-doors inspection. 

To do an outdoor inspection, begin by checking gutters and the foundation area for fallen shingles. Then look over the roof for missing or damaged shingles (you may even be able to do this from the ground with binoculars). If you've seen water damage on a ceiling or wall inside, try to locate the point on the outside of the roof immediately above this damage and then carefully work back and forth up the roof looking for the culprit leak. Be sure to check that flashings around chimneys, vents, and other protrusions have not developed holes or pulled loose. 

In addition to spotting leaks and water damage, your inspection will reveal whether the entire roof is due for replacement— 

• A roof of asphalt composite shingles (which may have either a fiberglass or natural fiber base) needs to be replaced when it has simply eroded away; first the granules on the surface disappear and then the shingles themselves wear down. The first places to wear out are the surfaces below the decorative cutouts or at the ends of shingles. When holes have eroded through the shingles, abundant leaks are in store. Although asphalt composite shingle roofs typically last more than 20 years, a roof's life might be less than 15 years or more than 50 years depending on how hot the roof gets, the quality of the original roofing materials, and other factors. Even before holes appear, your roof is on its last legs if shingles appear gray and bloated and if a piece of shingle will crumble easily between your fingers. 
• Wood shake or shingle roofs may go bad from drying out and splitting or warping. As shingles curl, they pull out nails and blow away. When you begin to lose them, it may be time for a new roof. Wood shake or shingle roofs occasionally last as long as 50 years, but one can fail much faster if it is in a shady area where dampness, rather than drying out, is the problem. In these instances, you may need to hire a roofer to treat your roof with a preservative spray every three to five years. It is not uncommon for a roof that cannot dry between rains to become mossy and rotted within 10 years. 
• Tile or slate roofs can last indefinitely (though individual pieces may have to be replaced). 
• Metal roofs need to be replaced when they become riddled with holes too difficult to patch; but if maintained properly, they, like high-quality slate and tile roofs, should last indefinitely. 
• Built-up roofs (composed of layers of hot bitumen and roofing felt, usually topped with stone) need to be replaced when they become so dried up and cracked in many places that leaks begin to occur. Other telltale signs are blisters and places where the layers have delaminated. A four-ply built-up roof should last 20 years or more. 
• Problems with single-ply and modified bitumen roofs are most likely to occur at seams and around the drains. Look for separation at the seams and bubbling or cratering of the membrane. Single-ply and modified bitumen roofs should last 20 years or more. 

Temporary Solutions 

If you discover a leak, you can easily apply a temporary remedy. 

One option is an emergency patch using roofing cement, available from most hardware stores. You just apply the compound generously to the roof surface, even if it is still wet. 

Another option, for a shingle roof, is to slide a piece of galvanized steel, copper, or aluminum under the shingle above the location of a leak. The metal should be large enough to cover the leaking area so that water will be carried away from the leak. 

Repairs 

There are also permanent repairs that some homeowners will be comfortable making. 

Shingles 

If you find loose asphalt composite shingles, remove the loose nails, drive in new nails, and cover the old holes and the heads of the new nails with roofing cement. If asphalt composite shingles are merely warped, hold them flat with a spot of roofing cement about the size of a quarter. 

If it is necessary to replace a shingle, that is more difficult. Very carefully lift the shingles that lie over the bad shingle, remove the nails holding the bad shingle, remove the shingle, insert a new one, and replace the nails. 

Built-up Roofs 

If you have a small defect at a bubble in a built-up roof, you may be able to cure it by slitting the bubble, cleaning out under the bubble with a trowel or putty knife, sliding cement in under the bubble, pushing the bubble down, driving in a row of nails on each side of the slit, and then covering the area with a layer of cement, a layer of roofing felt nailed around the edges, and a second layer of cement. 

For a larger defect in a built-up roof, the process is more difficult. You need to cut out a square of roofing material containing the defect. Cut out the area one layer at a time, with each deeper square smaller than the one above. Then cut new squares of felt to fit and put them in place, starting with a layer of cement and alternating cement and felt until you have replaced each layer. Drive nails around the perimeter of the top patch; then apply another layer of cement, another larger piece of felt to cover the whole area, and finally one more layer of cement. 

Metal Roofs 

Small holes in tin or galvanized steel roofs can be patched with a spot of solder. Larger defective areas in these roofs can be patched with a square of tin soldered around the edges or with a piece of canvas. If canvas is used, just apply a coat of paint as adhesive, then the patch of canvas, and then two or three more layers of paint. 

For small holes in aluminum roofs, use aluminum-pigmented caulking compound. Larger holes (an inch or more) can be patched with a piece of aluminum. Coat the patch with the aluminum-pigmented caulking compound and hold it in place with sheet metal screws that are coated in caulking. 

Flashing 

Many cracks in flashing can be repaired, temporarily at least, with a layer of roofing cement. Cement can also be used to fill small joints where flashing has pulled loose from a chimney; simply scrape out the old mortar or cement, put the flashing back in place, and fill the joint with cement. 

Moss and Algae Damage 

Moss or algae growth can be a problem for some roofs, particularly for roofs of wood shingles. When moss or algae grows on a roof, it holds moisture in, and can cause shingles to rot. Moss also can work down to the sheathing, causing structural deterioration. You can remove moss or algae growth with a commercial cleaner applied with a garden hose and/or by using a power washer. 

Re-roofing 

Some homeowners will feel comfortable doing more than simple repairs. You may, for example, feel you can replace damaged sheathing and rafters and you may wish to do your own re-roofing work. Many books and periodicals that will help you in these more difficult jobs are available in libraries and bookstores. 

Don't plan to take on an entire re-roofing job unless you're in excellent physical shape, not afraid of heights, well-informed about building construction, and not reluctant to do very hard, tedious work. A bundle of shingles weighs about 70 pounds, and a typical roof might require more than 60 bundles, each of which has to be lifted up. Also be wary of doing your own re-roofing on a steeply pitched roof (more than five or six inches up for every 12 inches horizontal), a roof that requires new structural work underneath, or one that has numerous dormers and other obstructions. Don't even consider putting on a built-up roof and think twice about installing your own tile roof; the tools and skills required for such roofs are beyond the reach of most homeowners. Finally, remember that thousands of dollars worth of damage can result if a rainstorm occurs when your house is without a roof. Although you can probably provide for temporary covering to avoid or minimize such damage, one advantage of professional roofers is that they almost certainly will work faster than you can. 

Common Roofing Mistakes 

You'll be more careful in choosing and dealing with roofers if you're aware of all that can go wrong. 

The Substructure 

• Where water has leaked and sheathing has rotted, shingles are simply nailed onto the rotten sheathing. The nails will pull out and shingles will come loose. 
• Unseasoned materials are used to replace sheathing. The materials will shrink, causing shingles to buckle. 

Flashings 

• At points where two different planes come together, flashing isn't put into place or woven valleys of shingles aren't used. Leaks will occur at the joints. 
• Old flashings are reused although they are corroded, eroded, or punctured. They will leak. 
• No counterflashing is used or what is used is not properly embedded in the mortar or adequately attached. Counterflashing should be installed over flashing materials to keep flashings dry; without it, water will leak past the step flashing. 
• Valley flashings are too narrow. In a heavy downpour, water will wash up under the shingles and turn back down under the flashings. 
• Flashings are not of heavy enough material. They will crack, puncture, or erode away, causing leaks. 
• Instead of consisting of a series of short- to medium-length pieces stepped over one another, flashings are long pieces, nailed at various places along their length. With expansion and contraction caused by temperature change, the metal will fatigue and split or nails will pull out. 

Nails 

• Nails are too short. If nails are not long enough, they may pull loose.  
• Nails do not have barbed (or otherwise deformed) shanks. They may pull loose. 
• Nailheads are too small. They may puncture the surface of the shingles, hastening deterioration and leaks. 
• Nails are driven into knotholes or spaces between sheathing boards. They will work their way up, forming lumps in shingles. 
• Too few nails are used. Shingles may come loose in wind or with repeated temperature changes. 

Shingles 

• Successive courses of shingles are not overlapped as required for the slope of the roof. Water will back up under shingles or go through nail holes. 
• Cutouts or edges (end joints) of shingles on successive courses are not adequately spaced or openings of one course are too near nail holes on the course below. Water may weave from an opening on one course down through a nearby opening or nail hole in the course below, causing leaks. 
• Too little space is allowed at joints of wood shakes or shingles. They may swell and buckle in damp weather. 
• Shingles or slates are too heavy for the framing. Sagging of the roof may damage shingles or create leaks where shingles do not lie properly. 
• Damaged or cracked shingles are used. They may leak. 
• In a new roof that is applied on top of an old one, tops of shingles are not properly placed against butt ends of shingles on the roof. The roof's surface will appear uneven. 
• The courses slant or the cutouts and edges are not properly aligned (they are neither random nor regular). Appearance suffers. 
• Bulges and warps in shingles of a previous roof are not flattened. Appearance suffers and leaks may occur. 

Miscellaneous 

• Gutters sag, are loose, do not slope adequately, or are installed too low. If gutters overflow or if water flowing from the roof overshoots gutters, it may cause water to enter the house. 
• A built-up roof is applied over a metal roof. The metal will expand and contract, tearing the felt. 
• Bituminous paint is used on a metal roof. It may form bubbles, allowing the metal to rust underneath. 

Where to Complain 

California Department of Consumer Affairs 

Better Business Bureaus