Roofing FAQ – (Roofing Definitions)
Q. How can a homeowner recognize when a roof system has problems?
A. All too often, roof system problems are discovered after leaking or other serious damage occurs. Periodic inspections (twice a year) often can uncover cracked, warped or missing shingles, loose seams and deteriorated flashings, excessive surface granules accumulating in the gutters or downspouts, and other visible signs of roof system problems. Indoors, look for cracked paint, discolored plasterboard and peeling wallpaper as signs of damaged roof areas.
Q. What are my options if I decide to re-roof?
A. You have two basic options: you can choose a complete replacement of the roof system, involving a tear-off of your existing roof system, or re-cover the existing roof system, involving only the installation of a new roof system. If you’ve already had one re-cover installed on your original roof system, check with a professional roofing contractor. In many instances, building code requirements allow no more than one roof system re-cover before a complete replacement in required.
Q. My roof leaks. Do I need to have it replaced completely?
A. Not necessarily. Leaks can result from flashings that have come loose or a section of the roof system being damaged. A complete roof system failure, however, generally is irreversible and a result of improper installation or choice of materials, or the roof system installation is inappropriate for the home or bulding.
Q. Can I do the work myself?
A. Most work should not be done by yourself. Professional roofing contractors are trained to safely and efficiently repair or replace roof systems. You can damage your roof system by using improper roofing techniques and severely injure yourself by falling off or through the roof.
Maintenance performed by home and building owners should be confined to inspecting roof systems during fall and spring to check for cracked or curling shingles and cleaning gutters filled with dead leaves and other debris.
Q. Only the underlayment has been installed on my roof and it rained last night. Now, the underlayment is wrinkled. Does it have to be replaced?
A. If the wrinkling isn’t severe enough to affect the shingle installation (i.e., the wrinkling won’t telegraph through the shingles and they won’t appear buckled or wavy once installed), the underlayment probably can remain in place. The effects of wrinkling also will be minimized by using heavier weight shingles.
Q. What is the best asphalt shingle to use on my roof?
A. Asphalt shingle material performance depends on the quality, quantity and compatibility of asphalt fillers, reinforcements and surface granules. There are two kinds of asphalt shingles (based on the type of reinforcement mat used); fiberglass and organic. Fiberglass shingles are more fire- and moisture-resistant than organic shingles. Organic shingles have good wind resistance, high tear strength and can be installed in colder temperatures.
Asphalt shingles should be in compliance with American Society for Testing and Materials (ASTM) standards and applicable building codes. Fiberglass shingles should meet ASTM D 3462, “Standard Specification for Asphalt Shingles Made from Glass Felt and Surfaced with Mineral Granules,” and organic shingles should meet ASTM D 225, “Standard Specification for Asphalt Shingles (Organic Felt) and Surfaced with Mineral Granules.”
Consumers also should keep in mind a roofing warranty’s length should not be the primary criterion in the selection of a roofing product or roof system because the warranty does not necessarily provide assurance of satisfactory roof system performance.
Q. Are two layers of 15# underlayment the same as one layer of 30# underlayment?
A. No. Two layers of underlayment are referred to as a “double-layer of underlayment” and there is a 19-inch overlap between layers. One layer of underlayment is called a “single-layer of underlayment” and there is 2 inches of overlap between layers. NRCA recommends a double-layer of underlayment for roof decks having slopes of 3:12 (14 degrees) up to 4:12 (18 degrees).
Q. One of the bids I have received uses staples instead of nails to install my asphalt shingles. Is that okay?
A. NRCA recommends galvanized steel or the equivalent corrosion-resistant roofing nails for asphalt shingle installation.
Q. I already have two single static vents on my roof and my quote suggests installing a ridge vent. Do I really need a ridge vent?
A. NRCA suggests the amount of attic ventilation be balanced between the eaves and ridge. The intent of a balanced ventilation system is to provide nearly equivalent amounts of ventilation area at the eave/soffit and at or near the ridge. For a balanced ventilation system to function properly, approximately one-half of the ventilation area must be at or near the ridge.
Q. My house has a roof with a 2.5:12 (11 degrees) slope. The manufacturer says it’s okay to use asphalt shingles, but my contractor says it isn’t. Who’s right?
A. There are some manufacturers (and even model building codes) that will allow the application of asphalt shingle roof having that slope; however, NRCA does not recommend shingles on slopes less than 4:12 (18 degrees). Asphalt shingle roof systems are watershedding and rely gravity and roof slope to effectively drain water off the roof.
Q. How long can I expect my roof system to last?
A. Most new roof systems are designed to provide useful service for about 20 years. Some roof system types, such as slate, clay tile and certain metal systems, can last longer.
Actual roof system life span is determined by a number of factors, including local climatic and environmental conditions, proper building and roof system design, material quality and suitability, proper application and adequate roof maintenance.
Roofing product manufacturers offer a variety of warranties on their products. Take a close look at those warranties to see what responsibilities and financial obligations manufacturers will assume if their products fail to reach their expected lives.
Q. What will a new roof system cost?
A. To get a good idea of price for your roof system, get three or four proposals from reputable contractors. Keep in mind that price is only one factor, and it must be balanced with the quality of the materials and workmanship.
For each roofing material there are different grades and corresponding prices. There are also a variety of styles and shapes. You need to look at the full product range and make a choice based on your budget and needs.
Within the roofing profession there are different levels of expertise and craftsmanship. Insist on a contractor who is committed to quality work.