Roofing Glossary

The most common roofing material in North America, made from fiberglass or organic mat coated with asphalt and surfaced with mineral granules. Available in 3-tab and architectural styles, with typical lifespans of 15-30 years.

A system of intake and exhaust vents that allows air to circulate through the attic space. Proper ventilation extends roof life, prevents ice dams, reduces cooling costs, and prevents moisture damage.

A rubber or metal flashing component that seals around pipes and vents where they penetrate the roof. Also called a pipe boot or plumbing vent boot. Boots deteriorate over time and are common leak sources.

A flat roof system consisting of multiple layers of reinforcing fabric and asphalt, topped with gravel or a cap sheet. Traditional commercial roofing method with 15-30 year lifespan.

The highest impact resistance rating for roofing materials under UL 2218 testing standard. Class 4 shingles withstand 2-inch steel ball impacts and qualify for insurance discounts of 10-30% in Colorado.

Metal flashing installed into masonry or siding that overlaps step flashing to direct water away from walls. Essential where roofs meet vertical surfaces like chimneys and walls.

A peaked saddle constructed behind a chimney or other roof projection to divert water around it. Also called a saddle. Prevents water pooling and leaks behind chimneys.

The structural surface (typically plywood or OSB) to which roofing materials are attached. The deck must be in good condition to support the roofing system. Standard thickness is 7/16" to 5/8".

A structure projecting from a sloped roof, usually containing a window. Dormers add complexity to roofing and require careful flashing to prevent leaks.

Metal flashing installed along the edges of the roof to direct water into gutters and prevent it from getting under roofing materials. Required by building codes in most jurisdictions.

The horizontal edge of a roof that overhangs the exterior wall. Eaves protect walls from water and provide shade. Ice dams commonly form at eaves in cold climates.

Ethylene Propylene Diene Monomer—a synthetic rubber membrane used on flat and low-slope roofs. Durable, UV-resistant, and cost-effective with 20-30 year lifespan. Available in black or white.

The vertical board along the roof edge where gutters are typically mounted. Fascia protects the roof edge and provides a finished appearance. Often damaged by ice dams or gutter problems.

Traditional asphalt-saturated underlayment installed under shingles. Being replaced by synthetic underlayments in many applications. Standard weights are 15-lb and 30-lb per 100 square feet.

Metal pieces installed to prevent water intrusion at joints, transitions, and penetrations in the roof system. Critical at valleys, chimneys, vents, walls, and skylights. Common materials include aluminum, galvanized steel, and copper.

The triangular portion of a wall between the edges of intersecting roof pitches. Gable roofs are the most common residential roof style in America.

Crusite rock particles embedded in asphalt shingles that provide UV protection, fire resistance, and color. Granule loss is a sign of shingle aging or hail damage.

A channel installed along roof eaves to collect and direct rainwater away from the foundation. Seamless gutters are custom-fabricated on-site for leak-free performance.

Roof damage caused by hailstone impacts, including dented shingles, granule loss, cracked shingles, and damaged flashing. Colorado averages 7-12 significant hail events annually.

The external angle formed where two sloping roof planes meet. Hip roofs have hips instead of gables at the ends. Hip shingles are specialty shingles designed for this application.

A ridge of ice that forms at the roof edge when melted snow refreezes, causing water to back up under shingles. Prevented by proper attic ventilation and insulation.

Self-adhering waterproof membrane installed in vulnerable areas like eaves, valleys, and around penetrations. Required by code in ice dam-prone areas. Provides backup leak protection.

A roof with a pitch between 1:12 and 4:12, requiring special materials and installation methods. Common on commercial buildings and some residential additions.

Roofing systems made from steel, aluminum, copper, or zinc panels. Standing seam and exposed fastener are the main styles. Offers 40-70 year lifespan with excellent hail and fire resistance.

A flat roofing material made from asphalt modified with rubber or plastic polymers. Applied in layers by torch, hot mop, or self-adhesive. Common on commercial and low-slope residential roofs.

Engineered wood panel made from compressed wood strands, commonly used for roof sheathing. Typically 7/16" or 1/2" thick. More affordable than plywood but more susceptible to moisture damage.

The angle of a roof expressed as a ratio of rise to run (e.g., 6:12 means 6 inches of rise per 12 inches of horizontal run). Affects drainage, material choices, and installation methods.

A layer of roofing material in a multi-layer system. Built-up roofs typically have 3-5 plies. The term also refers to the layers in composition shingles.

The inclined edge of a sloped roof over a gable. Rake edges require proper drip edge and may need special treatment to prevent wind-driven rain intrusion.

The horizontal line where two roof planes meet at the highest point. Ridge vents installed along this line provide excellent attic exhaust ventilation.

A continuous ventilation system installed along the roof ridge that allows hot air to escape from the attic. Works with soffit vents to create natural convection airflow.

A measure of thermal resistance in insulation. Higher R-values indicate better insulation. Colorado building codes typically require R-49 attic insulation for new construction.

The boards or panels attached to roof rafters that provide a nailing surface for roofing materials. Typically plywood or OSB. Must be in good condition for proper roof installation.

The underside of the roof overhang. Vented soffits provide crucial intake ventilation for the attic. Damaged soffits can allow pests and moisture into the attic.

A unit of roof measurement equal to 100 square feet. Roofing materials are typically sold by the square. Average residential roofs are 15-25 squares.

A metal roofing system where panels are joined by raised, interlocking seams. No exposed fasteners means better weather resistance. Premium option with 40-70 year lifespan.

L-shaped metal pieces woven into shingles where the roof meets a vertical wall. Each piece overlaps the one below, directing water away from the wall junction.

The first course of shingles installed along the eave, designed to seal under the first full course of shingles. Provides wind resistance and prevents water intrusion at the edge.

A single-ply flat roofing membrane that is heat-welded at seams. Energy-efficient white surface, 15-25 year lifespan. Popular for commercial and low-slope residential roofs.

A water-resistant layer installed directly on the roof deck before shingles. Provides secondary weather protection. Synthetic underlayments have largely replaced traditional felt.

The V-shaped intersection where two sloping roof planes meet. Valleys channel large amounts of water and require special flashing and underlayment to prevent leaks.

The system of intake and exhaust openings that allow air to flow through the attic space. Balanced ventilation requires equal intake (soffit) and exhaust (ridge) area.

Manufacturer warranties cover material defects (typically 25-50 years). Workmanship warranties from contractors cover installation (varies widely). Best Roof And Gutter provides lifetime workmanship warranty.

Roof damage from high winds including lifted, creased, or missing shingles, damaged flashing, and exposed deck. Colorado's Chinook winds can exceed 100 mph near the foothills.