Common Roofing Materials
Frequently Asked Questions
Getting Up on Roofs: Tips From the Experts
Glossary of Common Roofing Terms
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Must a leaking roof be replaced?
A roof leak is a sign that a problem exists, but it does not necessarily mean that your roof needs to be replaced. Sometimes leaks result from relatively minor causes, such as flashings which have come loose or shingles which have been damaged or blown off. If they are dealt with immediately, these problems can usually be solved by repairs. If ignored and allowed to compound, however, a minor leak can grow into a major problem which can only be solved by replacing the entire roof.
How can I minimize repair bills?
The best way to minimize roof repair bills is to prevent damage before it occurs. This means periodically inspecting the roof. Inspections should be made at least twice a year – in the early spring to assess any damage from winter weather and in early fall to detect any damage or deterioration which has occurred during the summer. Additional inspections should be made in the aftermath of unusual weather or events, such as heavy winds, hail, earthquakes or severe temperature conditions.
Steep roofs can be inspected from the ground or on a ladder. If you decide to inspect the roof from a ladder, follow these safety tips: inspect the ladder, rungs and rails for damage before using it; make sure the ladder is on solid, level ground; secure the ladder at the top to prevent it from slipping; extend the ladder at least three feet above the edge of the roof, and angle it 1 foot back for every 4 feet in eave height; and always use both hands when climbing the ladder. While inspecting a roof from a ladder, look for danger signs like missing, curled or cracked shingles, debris on the roof, clogged gutters and drains and severe weathering. If you are unable to safely make an inspection yourself, have a professional roofing contractor do it for you. The cost is reasonable, and it could prevent later repairs. Inside, check for evidence of possible leaks such as damp areas and stains on ceilings, peeling wallpaper and discolored wallboard.
Because they are generally more accessible, building and homeowners can conduct more detailed inspections of low slope (“flat”) roofs. The following items should be on your preventive maintenance checklist:
• Check the roof deck for loose boards and popped nails;
• Clear drains of debris and make sure they are screened to prevent clogging;
• Inspect the roof membrane for curled seams, cracks, splits, blisters and similar defects. On gravel roofs, look for bare spots. On mineral cap sheet roofs, look for excessive granule loss. On smooth surface roofs, inspect the general condition of the surface, looking for excessive drying, cracking and, where applicable, deterioration of the coating;
• Check parapet walls for cracks and open joints, and inspect the condition of metal counterflashings;
• Base flashings (where roofing is turned up at intersections of the roof deck and vertical surfaces) should be checked for sagging, cracks and splits;
• Inspect metal flashings around vents, skylights, equipment and other roof penetrations for rust and cracks;
• Look for signs of gravel stop and roof edging movement (especially at joints) which can crack the roof membrane; and
• Check to see if pitch pockets need to be refilled.
No roof should be expected to achieve its full life expectancy without regular preventive maintenance. The investment of a few hours each year to inspect the roof of your home or building and see that minor problems are identified and repaired before they can become major problems is well worth the time and trouble. And the expense pales in comparison to the cost of having to replace your roof prematurely.
Should I do the work myself?
Roofing is a serious business and is not for “do-it-yourselfers.” Repairing and replacing modern roofing systems requires specialized knowledge and highly specific skills. Working above the ground can also be dangerous. Home and building owners are best served by confining their efforts to periodic roof inspections and routine maintenance. Roof repair and replacement should be left to professional roofing contractors who are trained to perform these tasks safely, efficiently and correctly.
When is the best time to repair a roof?
Roof repairs should be made as soon as a potential problem is spotted. Unfortunately, problems such as leaks are often not apparent until it rains. During rainy periods, professional roofing contractors are “flooded” with calls for emergency repairs and may be unable to provide you with immediate service. If this should happen to you, be patient. Try to protect interior items by moving them out of the way or covering them with plastic. Place a bucket under the leaking area to catch the water. Sometimes, poking a small hole in the ceiling can allow trapped water to drain out and may prevent further ceiling damage. Don’t be panicked into contracting with an unlicensed, uninsured and/or inexperienced contractor or a semi-skilled handyman just because he can be there today. Remember: getting the job done right is usually better in the long run than getting the job done now.
When is the best time to replace a roof?
If you have your roof done in the spring, you will generally find better availability and faster service. The professional roofing contractor is able to schedule your job when he is not busy with emergency repairs and when weather conditions are most favorable for removing and replacing your roof safely and efficiently.
How much will a new roof cost?
The cost of a new roof is influenced by many factors, including whether the existing roof can be recovered or must be removed; the size, slope and configuration of the roof; how accessible the roof is; the roofing material to be installed; the time of year; and local labor rates. The best way to find out what a new roof will cost is to get several estimates from licensed, professional roofing contractors in the area. But remember that cost is only one part of the total picture. It must be balanced against the quality of the materials and workmanship, too. A low bid is not necessarily the best bargain.
Is it always necessary to tear off the existing roof?
No. It is not always necessary to tear off the old roof before installing a new one, but it is frequently advisable to do so. The California Building Code allows some types of roof to be recovered, rather than replaced, so long as there is no more than one existing application of roofing material on the existing roof and the existing roof is not water soaked or so deteriorated that it is not an adequate base for the new roof. The California Building Code does not allow wood shake, slate, clay, cement or asbestos-cement tile roofs to be recovered under any circumstances.
Even when not required by the Building Code, tearing off the existing roof can have advantages. Removing the existing roof will reveal if there any defects in the roof deck and allow them to be repaired prior to the installation of the new roof. Similarly, removing the existing roof will reveal if there are condensation problems in the attic. If there are, additional ventilation can be engineered into the new roof system to address the problem. Removing the old roof will usually result in a smoother finished roof surface. Roofing over an existing shingle roof, for example, may result in an uneven and aesthetically displeasing appearance. Keep in mind, too, that the existing roof structure may not have the capacity to support the combined weight of two roofs. This is especially true if a lightweight roofing material, such as asphalt shingles, is overlaid with a heavier material like concrete tile. Removing the existing roof will allow the roof structure to be strengthened to ensure adequate support for the increased load.
Where it is not prohibited by the California Building Code, recovering an existing roof will almost always be less expensive than tearing off the old roof before installing the new one. It is not always the best choice, however.
What kinds of warranties are available?
There are several types of warranties: contractor’s warranties that cover workmanship, manufacturer’s warranties that cover materials and extended manufacturer’s warranties that cover materials and labor. It is important that you clearly understand their respective terms and conditions.
It is absolutely essential to obtain a workmanship warranty from your contractor. This is the warranty that ensures that your roof will perform satisfactorily. It is your insurance against leaks. Contractor’s warranties on roofing and reroofing vary in length, but most are for two years or more. This assures that your roof’s performance will be proved through several weather cycles.
Manufacturers’ material warranties tend to be long, but limited. Most provide for the replacement of defective material (often on a prorated basis according to how long ago the material was purchased) and many do not cover the cost of installation. Few warrant the roof to be free of leaks. Restrictive provisions which limit the manufacturer’s liability (and your remedies) in the event of a problem are common. It is therefore unwise to judge a manufacturer’s warranty on the basis of its duration alone. Too often, the length of the warranty is based on marketing considerations and not on a realistic appraisal of how long the material will actually last.
An extended warranty that covers both materials and labor is sometimes available for purchase from the manufacturer at an additional cost. Extended warranties are more commonly offered to commercial than to residential customers. Even when they are available to homeowners, however, the cost can be prohibitive.
Make sure that you read carefully and clearly understand any and all warranties that you are offered. View unrealistically long warranties with skepticism. After all, a warranty is only as good as the contractor or the manufacturer who stands behind it.
What should I look for in a professional roofing contractor?
Whether they operate large or small businesses, professional roofing contractors all have the following traits in common: they are licensed by the State of California; they are well-established, with a permanent place of business, a telephone number, a tax identification number and, where appropriate, a business license; they are experienced and knowledgeable; they carry both workers’ compensation and liability insurance; and they are committed to worker education and safety.
Find out as much as you can about the contractors you are considering. Call a local trade association, such as the Associated Roofing Contractors of the Bay Area Counties, for background information and contractor referrals. Once you’ve contacted these contractors, ask those who bid on your job for the following:
• Evidence of a State contractor’s license and license number. A professional roofing contractor possessing a C-39 Roofing license may legally install any and all types of roof. A contractor holding a C-43 Sheet Metal or a C-51 Structural Steel license may legally install metal roofing only. Under very limited circumstances, a General Building (‘B’) contractor may also be legally permitted to install a roof. Verify that the license information given to you is valid by checking with the Contractors State License Board either via phone (1-800-321-2752) or over the internet (www.cslb.ca.gov);
• A written proposal that outlines what work is to be done, the amount that is to be charged, and the terms of any warranty or warranties to be given;
• Proof of liability insurance, which protects you against personal injury to you or others and against damage to your property or the property of others while the contractor is performing work on your home or building;
• Proof of workers’ compensation insurance, which protects the contractor’s employees while working on your job; and
• A list of customer references, which you should check to be sure that the contractor has performed as promised.
If you still have doubts, contact the Contractors State License Board or your local Better Business Bureau for further information.