This is a list of the most important GBA articles on roofs.
Roofs help keep the interior of your home dry, of course. But they often serve other functions as well: when properly designed, a roof can help keep your siding dry and can shade your windows on hot days. If a roof assembly includes insulation, the installation details need to be meticulously planned to avoid moisture problems.
If you are looking for an index that spans all categories, with a special focus on “how to” articles, check out this resource page: “How to do Everything.”
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Martin's Ten Rules of Roof Design
Lots of things can go wrong with roofs: bad flashing can cause leaks, a poorly designed valley can turn into a slow-moving glacier, and misplaced gutters can do more harm than good. Experienced roofers see a lot of stupid roofs.
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Every House Needs Roof Overhangs
Many residential designers pay too little attention to roof overhangs. Roof overhangs have several important functions: they can protect exterior doors, windows, and siding from rain; they can shade windows when solar heat gain is undesirable; and they can help keep basements and crawl spaces dry. A house with improper overhangs can overheat in the summer, can suffer from water entry problems at windows and doors, and can have premature siding rot. The most common design error is to make roof overhangs too stingy. It’s also possible (although much rarer) for roof overhangs to be too wide.
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Prevent Ice Dams With Air Sealing and Insulation
During snowy winters, many northern homes are plagued by ice dams. If your house suffers from wet ceilings during the winter, you may be ready to call up a contractor. Be careful, though: since most contractors don’t understand the causes of ice dams, they often suggest the wrong solution.
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All About Attics
Most six-year-olds can draw a house. The typical child’s depiction of a house shows a rectangular building with a door and a few windows, topped by a gable roof. This type of house is fairly common in most areas of the U.S. If the house was built 100 or more years ago, it usually had a cellar or basement underneath the first floor and an attic above the top floor.
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All About Attic Venting
Most homeowners and builders believe that attics should be vented. If you walk down to your local lumberyard and lean on the counter, the employees and nearby customers will offer a variety of opinions about why attics need to be vented. Unfortunately, it’s highly unlikely that the statements you hear will be true.
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How to Build an Insulated Cathedral Ceiling
UPDATED on May 31, 2018 with information on the cut-and-cobble method. Although the GBA website already contains many articles on the topic, we continue to receive frequent questions about the best way to insulate a cathedral ceiling. It’s therefore time to pull together as much information on the topic as possible and publish it in one place, to clarify the building science issues and code requirements governing insulated sloped roofs.
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How to Install Rigid Foam on Top of Roof Sheathing
UPDATED on December 15, 2017 with information on the U-factor alternative. A roof over a vented, unconditioned attic does not need to include any insulation. However, most cathedral ceilings and low-slope (flat) roofs are insulated roof assemblies: with this kind of roof, the insulation follows the slope of the roof. Insulated roof assemblies can be vented or unvented. There are lots of different ways to insulate this type of roof, but one of the best methods calls for the installation of rigid foam insulation above the roof sheathing.