Roofing Terms: Glossary
In addition to the type of shingles used as roofing material on your home, there are many other components that make up a roof. The following glossary will help you sort through the terminology associated with roofing.
- Shingles
- 80% of homes in the U.S. have asphalt shingle roofs. These are constructed of 12 x 36 inch sections that look like individual shingles when installed.
- Surface
- A roof's surface is the area on which all the roofing material sits. Roofing surfaces can be made of a variety of materials. The most common material in the U.S. is plywood with a covering of sheathing, felt and roofing shingles.
- Flashing
- Flashing is the metal or vinyl edging that is placed along roof intersections, dormers, chimneys, vent pipes and edges of the roof. It helps guide water away from roof joints and toward gutters.
- Most flashing is made of galvanized steel or aluminum. Galvanized steel is inexpensive but needs occasional painting to prevent rusting. Aluminum is moderately priced and naturally resistant to decay. Copper flashing is often used on slate or tile roofs. The most expensive, it lasts the longest.
- Deck
- A roof's deck consists of sheathing and underlayment, called roofing felt. The material used to finish the roof determines deck types. Most roofs require solid plywood or oriented strand board sheathing, while wood shingle and tile roofs need spaced board sheathing.
- Roofing Felt
- The protective layer that sits between the roof sheathing and the shingles.
- Gutters
- Metal channels that are attached to the roof edges, used to draw water down and away from the house and its foundation. Most gutters consist of gutter sections, drop outlets and downspouts. Gutters can be constructed of aluminum, galvanized steel, vinyl, wood or copper.
- After your roof sheds any water from the house, the gutters and downspouts act as a drainage system for your roof.
- Roof pitch and slope
- Roof pitch can dramatically affect installation and repair. In fact, the slope or pitch of a roof can determine the kind of roofing material you use.
- Slope and pitch are two terms often used interchangeably, but they actually mean different things. Slope is described in inches of vertical rise per foot of horizontal run. For example a gently sloped roof that rises 4 inches for every 12 inches of house covering is said to have a 4 in 12 slope. Pitch is expressed as a fraction - the ration of rise to the total span of the entire roof. The same gentle 4 in 12 slope translates into a 1:6 pitch. Completely confused? Don't sweat. We don't expect you to calculate the exact pitch or slope of your roof.
- So go outside and take a look at your roof, and then come back. A close, approximate guess is fine.
- Storey
- Height considerations: A storey is a floor that's above ground. Most homes are either one or two storeys. If your house has more than one storey, your roofing job may require more specialized equipment.
- Roofing problems
- Dormers create additional openings in your roof, which will affect your roof installation. One notable area is at the joints, which will need to be sealed with metal flashing. The style of dormer can also affect your roofing material. A shed dormer will decrease the slope of your roof over the opening. You will need to choose a roofing material that can shed water on a decreased slope. A gabled dormer often has higher pitches which will shed water more easily.
- Water Diverter
- Similar to gutters, a water diverter is a piece of metal that helps to control the flow of water as it drains from the roof.
- Heat Tape
- Heat tape is an electrical feature that heats gutters during the winter and keeps water flowing.
- Ridge Vent
- A ridge vent is a special vent that sits along the top ridge of your roof. Like other vents, it allows your attic to breathe, but it sits underneath the roofing material, making it less visible than standard vents. Ridge vents help to prevent ice dams and improper snow melt off.
by Kathy Maynard, reprinted courtesy of HomeAdvisor.com