Roofers - Avoid Problems By Speaking Their Language

We don’t really think about the roofs on our homes until they have a problem. When they do, we call a roofer. Then comes the problem of actually speaking with the roofer. Why? Well, they have a language all their own. Here are some common roofing terms.

Blister: A pocket of air trapped between layers of felt or membrane. Blisters are usually caused by water or other foreign substances.

Valley: The intersection of two sloping roofs joining at an angle to provide water runoff.

Cleat: A continuous metal strip used to secure two or more metal roof components together. Commonly used along with coping or gravel stop on tall buildings.

Pitch: The degree of roof inclined expressed as the ratio of the rise, in feet, to the span, in feet.

Closed Cut Valley: A method of valley treatment in which shingles from one side of the valley extend across the valley while shingles from the other side are trimmed two inches from the valley centerline. The valley flashing is not exposed.

Dormer: A framed window unit projecting through the sloping side of the roof.

Boot: A piece of material preformed to protect roof penetrations from dirt, moisture and other foreign and/or damaging substances.

Bundle: A package of shingles. There are three, four or five bundles per square.

Composition Shingle: A type of shingle used in steep-slope roofing and generally comprised of weathering-grade asphalt, a fiber glass reinforcing mat, an adhesive strip, and mineral granules.

Eave Details: The part of a roof which projects out from the side wall, projecting the edge of the roof.

Nesting: A method of re-roofing with new asphalt shingles over old shingles in which the top edge of the new shingle is butted against the bottom edge of the existing shingle tab.

Built-Up Roof Membrane: A roof membrane consisting of layers of bitumen, which serves as the waterproofing component, with plies of reinforcement fabric installed between each layer.

Flat Seam: Is a term used to describe when two metal panels are joined in a shingle fashion. The two panels can either be overlapped and fastened or folded and interlocked.

Drip Edge: A narrow strip of non-corrosive, non-staining, finishing material installed along the eaves and rakes to allow water run-off to drip clear of underlying construction. On eaves where gutters are present, this material is commonly called gutter apron.

Bitumen: Any of various flammable mixtures of hydrocarbons and other substances, occurring naturally or obtained by distillation from coal or petroleum, that are a component of asphalt and tar and are used for surfacing roads and for waterproofing.

Elongation: The ability of a membrane to be stretched and lengthened by force to accommodate movement. Roofing membranes have forces exerted on them from the building movement and the membrane must be able to accommodate these movements.

Steep Slope: Roof that pitches more than 45 degrees.

Low Temperature Flexibility: The ability of a membrane to remain flexible and resist cracking after it has been exposed to low temperatures.

Ice dam: Condition formed at the lower roof edge by the thawing and re-freezing of melted snow on the overhang. Can force water up and under shingles, causing leaks.

Step Flashing: A corrosion-resistant sheet metal used to waterproof the angle between a chimney, skylight, dormer, etc. and a sloping roof.

Talking with a roofer can be like visiting a foreign country. The conversation tends to involve a lot of loud, slow pronunciations and pointing. Understanding the basic terms used with a roof should help you avoid problems.