Econo Roofing Blog
Roofing glossary. 80+ terms explained in plain English.
Last updated April 1, 2026
Your contractor shouldn't speak a language you don't understand. This glossary covers every roofing term you're likely to encounter, from estimates to checks to warranty documents. Bookmark it and refer back as needed.
Roofing has its own vocabulary. When your contractor says "the drip edge needs replacing" or "the flashing around the cricket is failing," you shouldn't have to guess what that means. This A-Z glossary defines 80+ roofing terms in plain English so you can understand estimates, inspection reports, and warranty documents with confidence.
A
Architectural shingles
Multi-layered shingles bonded together to create a thicker, textured appearance that resembles wood shake or slate. Also called dimensional or laminated shingles. They are heavier and more wind-resistant than three-tab shingles and usually last 30 to 50 years. Most roof replacements today use architectural shingles as the standard choice.
Asphalt shingles
The most common residential roofing material in the United States. Made from a fiberglass mat coated with asphalt and topped with ceramic granules for UV cover. Available in three-tab and architectural styles. Affordable, widely available, and compatible with most roof slopes. See our roofing materials guide for a full comparison.
Attic ventilation
The system of intake and exhaust vents that allows air to circulate through your attic space. Proper ventilation prevents heat buildup in summer and water accumulation in winter. In the Central Valley, inadequate attic ventilation is one of the most common causes of premature shingle failure. Most maker warranties require specific ventilation levels to remain valid. Related: insulation services.
Algae staining
Dark streaks or discoloration on roof shingles caused by the blue-green algae Gloeocapsa magma. Algae feed on the limestone filler in shingles and thrive in warm, humid conditions. Algae staining is cosmetic and does not damage the roof structurally, but it reduces curb appeal. Algae-resistant shingles contain copper granules that inhibit growth. Existing staining can be removed with expert roof cleaning.
B
Blistering
Raised bubbles or bumps on the surface of shingles or flat roofing membranes. Caused by trapped water or gases expanding under heat. Minor blistering is cosmetic, but severe blistering can expose the underlying mat and accelerate wear. Common in hot climates like the Central Valley. If you notice blistering, schedule a roof repair assessment.
Boot (pipe boot)
A flexible rubber or metal sleeve that fits around plumbing vent pipes where they penetrate the roof surface. Boots create a watertight seal at the pipe opening. They are one of the first components to fail on an aging roof because the rubber degrades under UV exposure. A cracked pipe boot is a common source of roof leaks.
Built-up roofing (BUR)
A flat roofing system made from many alternating layers of bitumen (asphalt or tar) and reinforcing fabric. Sometimes called "tar and gravel" roofing. BUR systems have been used on commercial buildings for over a century. They provide excellent waterproofing and can last 20 to 30 years. See our flat roofing services for more.
Blow-off
Shingles or other roofing materials that have been torn or lifted from the roof by strong winds. Blow-offs usually occur when shingles are improperly nailed, the adhesive strip fails to seal, or wind speeds go over the material's rated resistance. After any big windstorm, a roof inspection can identify blow-offs before they lead to water damage. Related: storm damage services.
C
Cap sheet
The top layer of a built-up or modified bitumen roofing system. Cap sheets are usually granulated on the surface for UV cover and weather resistance. They serve the same function as shingles on a steep-slope roof: protecting the layers beneath from the elements.
Chalk line
A reference line snapped onto the roof deck or existing surface using a chalk-coated string. Roofers use chalk lines to ensure shingles are installed in straight, evenly spaced rows. Proper alignment prevents water from tracking behind shingle edges and reaching the deck below.
Cool roof
A roofing system designed to reflect more sunlight and absorb less heat than a conventional roof. Cool roofs use reflective materials, lighter colors, or specialized coatings to reduce surface heat. In California, Title 24 energy code needs cool roof materials for most re-roofing projects. See also: roof coating.
Counter flashing
A piece of metal flashing installed into a wall or chimney that overlaps the base flashing below. Counter flashing covers the top edge of step flashing to prevent water from getting behind it. It is usually embedded into a mortar joint or secured with sealant. Proper counter flashing is key at chimney and wall intersections.
Cricket
A small, peaked structure built behind a chimney or other vertical projection on a roof. A cricket diverts water around the obstruction rather than allowing it to pool behind it. Without a cricket, water and debris accumulate behind the chimney, leading to leaks and sped up wear. Building codes require crickets for chimneys wider than 30 inches.
Curbing
A raised frame built on a flat roof to support equipment such as HVAC units, skylights, or vents. The curb elevates the equipment above the roof surface so water can drain around it. Proper flashing around the curb is key to prevent leaks at the equipment-to-roof junction.
Collar (roof collar)
A pre-formed metal or rubber flange that fits around a vent pipe or other circular leak to create a watertight seal. Similar to a pipe boot but sometimes refers mainly to the metal base plate. Collars wear out over time and should be inspected during routine roof maintenance.
Condensation
Water that forms when warm, humid air meets a cooler surface. In roofing, condensation occurs in the attic when warm interior air rises and contacts the cold underside of the roof deck. Over time, condensation leads to mold, mildew, and wood rot. Proper ventilation and vapor barriers prevent condensation damage.
D
Deck / Decking
The structural surface, usually plywood or oriented strand board (OSB), that is nailed to the roof trusses or rafters. The deck is the foundation of the entire roofing system. Everything else (underlayment, shingles, flashing) is installed on top of it. Damaged or rotting decking must be replaced during a roof replacement before new materials go on.
Downspout
A vertical pipe that carries rainwater from the gutter down to the ground or a drainage system. Downspouts should discharge water at least 4 to 6 feet away from the foundation to prevent water pooling and basement leaks. Clogged or disconnected downspouts are a common cause of foundation water damage. Related: gutter installation.
Dormer
A small structure that projects from a sloped roof, usually containing a window. Dormers add light, ventilation, and usable space to attic areas. They also create more roof lines and intersections that require careful flashing to prevent leaks.
Drip edge
An L-shaped metal strip installed along the edges of the roof to direct water away from the fascia and into the gutters. Drip edge prevents water from wicking back under the roofing material by capillary action. Building codes require drip edge on most new roofing installs. It is one of the least expensive but most key components of a properly installed roof.
Dry rot
Wood decay caused by certain fungi that break down the cellulose in timber, leaving it soft, crumbly, and structurally damaged. Despite the name, dry rot needs some water to begin. On a roof, dry rot usually affects the decking, fascia, and rafter tails. Damaged wood must be cut out and replaced before new roofing materials are installed. See our dry rot repair guide.
E
Eave
The lower edge of a roof that overhangs the exterior wall. Eaves direct rainwater away from the walls and foundation. The underside of the eave is enclosed by the soffit,, the vertical face is covered by the fascia. Eave length affects both water cover and the looks proportions of a building.
EPDM
Ethylene Propylene Diene Monomer. A synthetic rubber membrane used mostly on flat and low-slope commercial roofs. EPDM comes in large sheets (up to 50 feet wide) that are either glued down, mechanically fastened, or ballasted with gravel. Known for UV resistance, flexibility, and a typical lifespan of 25 to 30 years. See our flat roofing page.
Elastomeric coating
A flexible, rubber-like roof coating that stretches and contracts with heat changes without cracking. Elastomeric coatings are applied as a liquid and cure into a seamless, reflective membrane. They are commonly used to extend the life of flat and low-slope roofs by 10 to 15 years. See our elastomeric coating guide.
Exposure
The portion of a shingle, tile, or shake that is visible and exposed to weather after install. For standard architectural shingles, exposure is usually about 5 to 5-5/8 inches. Correct exposure is key because too much exposes the nail line, and too little wastes material and adds unnecessary weight.
F
Fascia
The vertical board that runs along the lower edge of the roof, directly behind the gutter. The fascia caps the ends of the roof rafters and provides a mounting surface for the gutter system. It is usually made from wood, aluminum, or composite material. Damaged fascia allows water behind the gutter and into the soffit area. Related: gutter installation.
Felt (underlayment)
A traditional roofing underlayment made from organic or fiberglass mat saturated with asphalt. Also called tar paper. Felt comes in two weights: 15-pound and 30-pound. It is installed over the roof deck and under the shingles as a secondary water barrier. Many new installs have replaced felt with synthetic underlayment, which is lighter and more tear-resistant.
Flashing
Thin pieces of metal (usually aluminum, galvanized steel, or copper) installed at joints, changes, and penetrations on a roof to direct water away from vulnerable areas. Flashing is used around chimneys, vents, skylights, walls, and valleys. It is the most failure-prone component on most roofs, and improper flashing is the leading cause of roof leaks. See also: step flashing, counter flashing, kick-out flashing. Related: roof repair services.
Flat roof
A roof with a slope of less than 2:12 (less than 2 inches of rise per 12 inches of horizontal run). Flat roofs are not truly flat; they have a slight slope to allow water drainage. Common on commercial buildings and some new residential designs. Flat roofs use membrane systems (TPO, EPDM, PVC, or modified bitumen) rather than shingles. See our flat roofing services.
G
Gable
The triangular section of a wall between the edges of intersecting roof slopes. A gable roof is one of the most common roof shapes: two sloping sides that meet at a central ridge. Gable ends are vulnerable to wind uplift and require proper bracing in high-wind areas.
Granules
Small, crushed rock particles embedded in the surface of asphalt shingles. Granules protect the asphalt layer from UV radiation, add fire resistance, and provide the shingle's color. Finding excessive granules in your gutters is a sign of aging shingles. Some granule loss is normal on new roofs, but speeding up loss indicates the shingles are nearing end of life.
Gutter
A channel attached along the eave of the roof that collects rainwater and directs it to downspouts and away from the foundation. Gutters prevent water damage to siding, landscaping, and the foundation. Clogged or damaged gutters can cause water to back up under the roof edge and into the soffit. See our gutter installation services.
GAF
One of the largest roofing material makers in North America. GAF produces shingles (Timberline series), underlayment, ventilation, and commercial roofing products. Their contractor certification program includes three tiers: Certified, Master Elite, and independent. Master Elite contractors represent about 3% of all roofers and can offer GAF's top Golden Pledge warranty. Econo Roofing holds GAF Master Elite status. See our certifications.
Gutter guard
A cover, screen, or filter installed over gutters to prevent leaves and debris from clogging the channel. Gutter guards reduce maintenance frequency but do not remove it entirely. They come in many styles including mesh screens, foam inserts, and reverse-curve designs. Proper gutter guards help keep steady water flow during heavy rains.
H
Hip
The external angle formed where two sloping roof planes meet at an outward corner. A hip is the opposite of a valley (which forms an inward corner). Hip lines require hip cap shingles or special ridge cap material to cover the joint and keep a watertight seal.
Hip roof
A roof where all four sides slope downward from the ridge to the eaves. Hip roofs have no vertical gable ends, making them more aerodynamic and resistant to wind uplift than gable roofs. They cost more to build due to the more ridge and hip lines but offer superior performance in windy conditions.
I
Ice dam
A ridge of ice that forms at the eave when snow on the upper roof melts, runs down, and refreezes at the colder eave edge. Ice dams force water to back up under shingles, causing leaks and interior damage. While uncommon in the Central Valley, homes in foothill communities and higher elevations (Sonora, Copperopolis) can know-how them. Proper insulation and ventilation prevent ice dams.
Impact resistance
A measure of how well a roofing material withstands damage from hail, falling branches, and debris. Impact resistance is rated on a scale from Class 1 (least resistant) to Class 4 (most resistant) under the UL 2218 testing standard. Class 4 shingles may qualify for insurance premium discounts in areas prone to hail or storm damage. Related: storm damage services.
J
Joist
A horizontal structural member that supports a ceiling or floor. In roofing context, ceiling joists run between walls and support the ceiling below the attic space. They also resist the outward thrust of the rafters. Joists differ from rafters, which follow the slope of the roof, and trusses, which are prefabricated triangular frames.
K
Kick-out flashing
A small, angled piece of flashing installed where a roof edge meets a sidewall. Kick-out flashing directs water away from the wall and into the gutter instead of allowing it to run down the siding. Missing kick-out flashing is a common cause of hidden water damage behind exterior walls. It is a code requirement in many jurisdictions.
L
Laminated shingles
Another name for architectural shingles. The "laminated" refers to the manufacturing process of bonding two or more layers together. This creates the thicker, dimensional profile that distinguishes them from flat, single-layer three-tab shingles. Laminated shingles are the industry standard for residential roofing.
Leak barrier
A self-adhering waterproof membrane installed at vulnerable areas of the roof deck before shingles are applied. Also called ice and water shield. Leak barriers are applied along eaves, in valleys, around penetrations, and at other key change points. They bond directly to the deck and seal around nail shanks, providing an extra layer of cover where water is most likely to collect or be driven by wind.
M
Mansard roof
A four-sided roof with two slopes on each side. The lower slope is much steeper (nearly vertical) than the upper slope. Mansard roofs boost usable attic space and were historically popular in French architecture. They require careful flashing and drainage management due to the change between steep and shallow slopes.
Metal roofing
A roofing system made from metal panels or shingles, usually steel, aluminum, copper, or zinc. Metal roofs last 40 to 70 years, reflect solar heat, resist fire and wind, and are fully recyclable. Available in standing seam, corrugated, and metal shingle styles. See our metal roofing services for details on options available in the Central Valley.
Modified bitumen
A flat roofing material made from asphalt that has been modified with rubber or plastic polymers for added flexibility and durability. Applied in sheets that are torched, mopped, or self-adhered to the roof deck. Modified bitumen is one of the most common commercial and low-slope roofing systems. It usually lasts 15 to 25 years with proper maintenance.
Moss
A small, non-vascular plant that can grow on roof surfaces, especially in shaded, damp areas. Moss holds water against the roof surface, which speeds up shingle wear and can lift shingle edges, allowing water underneath. Regular roof cleaning removes moss before it causes damage. See our guide on removing moss from your roof.
Membrane
A steady, flexible sheet of waterproof material used as the primary weather barrier on flat and low-slope roofs. Common membrane types include TPO, PVC, EPDM, and modified bitumen. Unlike shingle systems that rely on overlapping layers, membranes provide a single unbroken surface. Seams are either heat-welded or adhered depending on the material.
N
Nail pop
A roofing nail that has worked its way back up through the shingle surface. Nail pops are caused by the natural expansion and contraction of the roof deck due to heat changes. A popped nail creates a small raised bump on the shingle and, more importantly, a potential leak point. Nail pops should be repaired promptly by driving the nail back in and sealing it, or replacing it.
O
Overhang
The portion of the roof that extends beyond the exterior wall of the building. Overhangs protect walls, windows, and the foundation from rain. The length of the overhang affects how much weather cover the walls receive. Overhangs also shade windows, reducing cooling costs in hot climates.
Owens Corning
One of the largest roofing material makers in the United States. Owens Corning produces shingles (Duration, TruDefinition), underlayment, and ventilation products. Their contractor certification program has three tiers: Preferred, Platinum Preferred, and independent. Econo Roofing is the only Owens Corning Platinum Preferred contractor in Stanislaus and Merced County, qualifying homeowners for the highest warranty tier available.
OSB (Oriented Strand Board)
An engineered wood panel made from compressed layers of wood strands bonded with adhesive. OSB is one of the two standard materials used for roof decking (the other being plywood). It is less expensive than plywood and performs similarly in most applications. OSB is more susceptible to water damage at cut edges, so proper underlayment and ventilation are key when OSB decking is used.
P
Parapet
A low wall or barrier along the edge of a flat or low-slope roof. Parapets are common on commercial buildings and provide fall cover, wind resistance, and a finished architectural appearance. The junction between the parapet, the roof surface needs careful flashing and coping (the cap on top of the parapet) to prevent leaks.
Pitch
The steepness of a roof, expressed as the ratio of vertical rise to horizontal run. A 6/12 pitch means the roof rises 6 inches for every 12 inches of horizontal distance. Pitch determines which roofing materials can be used, how water sheds, the amount of material needed,, the overall cost. Most residential roofs in the Central Valley have pitches between 4/12 and 8/12. See our roof pitch guide.
Plywood
A structural panel made from thin layers of wood veneer glued together. Plywood is one of the two standard materials used for roof decking (the other being OSB). CDX plywood is the most common grade used in roofing. It provides a solid, flat surface for underlayment and shingles to attach to.
Ponding
Standing water that remains on a flat roof for 48 hours or more after rain stops. Ponding indicates a drainage problem: either the slope is insufficient, drains are clogged, or the deck has sagged. Steady ponding speeds up membrane wear, adds structural weight, and in time causes leaks. See our ponding water solutions guide.
PVC (Polyvinyl Chloride)
A single-ply roofing membrane used on flat and low-slope commercial roofs. PVC membranes are heat-welded at the seams, creating a steady waterproof surface. Known for chemical resistance, fire resistance, and high reflectivity. PVC is a strong choice for restaurants, industrial buildings, and any structure where rooftop grease or chemical exposure is a concern.
R
Rafter
A sloped structural member that extends from the ridge to the eave and supports the roof deck. Rafters are the traditional framing method for sloped roofs, cut and assembled on-site (as opposed to prefabricated trusses). The size and spacing of rafters determine how much weight the roof can support, including snow loads, roofing materials, and equipment.
Rake
The sloped edge of a roof that runs from the eave to the ridge at the gable end. The rake is the inclined edge of the roof (as opposed to the eave, which is the horizontal edge). Rake edges need drip edge and proper flashing to prevent wind-driven rain from getting under the roofing material.
Ridge
The horizontal line at the top of the roof where two opposing slopes meet. The ridge is the highest point on a sloped roof. It is capped with ridge cap shingles or ridge tiles and usually contains a ridge vent for attic ventilation.
Ridge cap
Specially shaped shingles or tiles designed to cover the ridge line of a roof. Ridge caps are thicker than regular shingles and bend over the peak to cover the joint where two slopes meet. Proper ridge cap install prevents water and wind from penetrating the most exposed line on the roof.
Ridge vent
A ventilation opening that runs along the ridge of the roof, covered by ridge cap shingles. Ridge vents allow hot, moist air to escape from the attic. They work in conjunction with soffit vents (intake) to create steady airflow through the attic space. Ridge vents are the preferred exhaust ventilation method for most residential roofing systems.
R-value
A measure of heat resistance. The higher the R-value, the better the material insulates. In roofing, R-value applies mostly to attic insulation and some rigid foam insulation boards installed in roof assemblies. California energy code specifies minimum R-values for attic insulation based on climate zone. The Central Valley usually falls in Climate Zone 12. Related: insulation services.
Roof coating
A liquid-applied membrane that is rolled, sprayed, or brushed onto an existing roof surface. Coatings can extend the life of a flat or low-slope roof by 10 to 15 years, improve reflectivity, and seal small cracks. Common types include acrylic, silicone, and elastomeric coatings. See our roof coating services.
S
Saturated felt
Roofing felt that has been saturated (soaked) with asphalt to make it water-resistant. Used as an underlayment layer between the roof deck and the outer roofing material. Saturated felt has been a standard underlayment for decades, though synthetic alternatives are more often common.
Sheathing
Another term for roof decking. Sheathing refers to the layer of plywood or OSB panels that are nailed to the roof structure (rafters or trusses) to create a solid surface for the roofing system. Sheathing must be structurally sound and free of rot before any roofing material is installed.
Shingle
An person unit of roofing material designed to be installed in overlapping rows. Shingles can be made from asphalt, wood (shakes), slate, tile, or composite materials. The overlapping pattern ensures water runs down and off the roof without reaching the deck beneath. Asphalt shingles are by far the most common type in residential roofing.
Skylight
A window installed in the roof to provide natural light to the interior. Skylights can be fixed or operable (openable for ventilation). They require precise flashing and proper install to prevent leaks. Old or poorly installed skylights are one of the most common sources of roof leaks. See our skylight services and skylight repair guide.
Slope
The angle or incline of a roof surface. Slope and pitch are often used interchangeably, though technically slope is expressed as a ratio (e.g., 4:12) while pitch is the ratio of rise to the full span. Slope determines which roofing materials are appropriate and how effectively water drains from the surface.
Soffit
The horizontal underside panel that connects the bottom of the fascia to the exterior wall, enclosing the underside of the eave. Soffits protect the roof structure from weather and pests. Vented soffits contain small perforations or slots that allow outside air to enter the attic, providing the intake half of the attic ventilation system.
Solar reflectance index (SRI)
A value that measures a roofing material's ability to reflect solar heat and release absorbed heat. SRI combines reflectance and heat emittance into a single number from 0 (absorbs all heat) to 100+ (reflects all heat). Higher SRI values indicate a cooler roof. California's Title 24 specifies minimum SRI rules for roofing materials in unique climate zones.
Standing seam
A type of metal roofing where long panels are joined by raised, interlocking seams that stand vertically above the flat panel surface. The seams are usually 1 to 2 inches tall. Standing seam systems are highly weather-resistant because the fasteners are concealed beneath the seam, removing exposed screw holes. They are available in steel, aluminum, copper, and zinc.
Step flashing
Small, L-shaped pieces of metal flashing installed at each shingle course where a roof meets a vertical wall (such as a dormer or chimney sidewall). Each piece overlaps the one below and is woven between shingle courses. Step flashing is the correct method for waterproofing roof-to-wall changes. Steady flashing (a single long piece) is an inferior alternative that often fails.
Storm damage
Roof damage caused by severe weather events including high winds, hail, falling trees, or heavy rain. Storm damage may be covered by homeowner's insurance (unlike normal wear). After a storm, a expert inspection can document damage for insurance claims. See our storm damage and insurance page and insurance claim guide.
Substrate
The surface or material beneath the roofing system. On a typical residential roof, the substrate is the plywood or OSB decking. On a commercial re-roof, the substrate may be the existing roof membrane. The condition of the substrate determines whether a new roofing system can be installed directly over it or whether removal and replacement are needed.
T
Tar
A thick, dark, viscous liquid derived from coal or petroleum, historically used as a waterproofing agent in built-up roofing systems. In new roofing, "tar" is used colloquially to refer to asphalt-based adhesives and coatings used in flat roof applications. True coal tar is more often rare and is being replaced by polymer-modified asphaltic products.
Three-tab shingle
A flat, single-layer asphalt shingle with three uniform tabs (cutouts) along the lower edge. Three-tab shingles are thinner, lighter, and less expensive than architectural shingles. They usually last 15 to 25 years, compared to 30 to 50 years for architectural shingles. While still available, three-tab shingles have been largely replaced by architectural shingles in new residential construction.
Tile roofing
A roofing system made from person tiles, usually clay or concrete. Tile roofs are extremely durable (50 to 100+ years), fire-resistant, and energy-good. They are common in Mediterranean, Spanish, and Southwestern architectural styles. Tile roofs are heavier than asphalt and require a structural assessment before install. See our tile roofing services.
Title 24
California's Building Energy Savings Standards, part of the California Code of Regulations. Title 24 sets rules for energy-good building design, including cool roof rules for re-roofing projects. In the Central Valley's climate zone, Title 24 needs minimum reflectance and emittance values for roofing materials. See our guide on Title 24 cool roof requirements.
TPO (Thermoplastic Polyolefin)
A single-ply roofing membrane used on flat and low-slope commercial roofs. TPO is heat-welded at the seams and known for its energy savings, reflectivity, and resistance to UV radiation. It is one of the fastest-growing commercial roofing materials. TPO usually lasts 20 to 30 years. See our complete TPO guide.
Truss
A prefabricated, triangular structural framework that supports the roof. Trusses are engineered to specific load rules and span the width of the building. They are manufactured off-site and craned into position during construction. Unlike stick-built rafter systems, trusses should not be cut or modified without engineering approval.
U
Underlayment
A water-resistant layer installed directly on the roof deck, beneath the outer roofing material (shingles, tiles, or metal). Underlayment serves as a secondary barrier against water if the outer material is damaged. Types include asphalt-saturated felt, synthetic sheets, and self-adhering membranes. Most maker warranties specify which underlayment products must be used to keep coverage.
V
Valley
The internal angle formed where two sloping roof planes meet. Valleys channel large volumes of water and are one of the most leak-prone areas on any roof. They can be lined with metal flashing (open valley) or covered with overlapping shingles (closed valley). Proper valley install is key to roof performance.
Vapor barrier
A material that resists the movement of water vapor through walls, ceilings, and floors. In roofing, vapor barriers are sometimes installed on the warm side of insulation to prevent water from the living space from reaching the cold roof deck. Here it could condense and cause rot. Not all roof assemblies require a vapor barrier; climate and building design determine whether one is needed.
Ventilation
The system that moves air through the attic space. Good roof ventilation uses intake vents (usually in the soffits) and exhaust vents (ridge vents, turbines, or powered fans) to create steady airflow. Proper ventilation reduces summer heat buildup, prevents winter water problems, and is needed by most roofing material warranties. Related: insulation and ventilation.
W
Warranty
A written guarantee from a maker or contractor covering the performance of roofing materials or workmanship for a specified period. Roof warranties have two parts: the maker's material warranty and the contractor's workmanship warranty. Coverage duration, exclusions, and transferability vary significantly. See our complete roof warranty guide and certifications page.
Waterproofing
The process of making a surface or structure impervious to water. In roofing, waterproofing refers to the complete system of membranes, flashings, sealants, and drainage components that prevent water from penetrating the building envelope. Good waterproofing addresses not just the roof surface but all penetrations, changes, and edge conditions.
Wind uplift
The upward force exerted on a roof by wind flowing over and around a building. During high winds, negative pressure on the roof surface can lift shingles, tear membranes, and in extreme cases, separate the entire roof structure from the building. Wind uplift resistance is rated by testing standards (UL 580, FM 4470) and is a key factor in roofing material selection for exposed locations.
Z
Zinc strip
A narrow strip of zinc metal installed along the roof ridge or below the ridge cap. When rain washes over the zinc, it releases zinc carbonate, which inhibits the growth of moss, algae, and lichen on the roof surface below. Zinc strips are a low-maintenance, long-lasting preventive measure. They are most good on north-facing slopes and shaded areas where moss growth is most common.
Our team is happy to explain anything on your estimate or inspection report. Call us or request a free inspection and we'll walk you through every detail in plain English.
Get a Free Estimate →Frequently asked questions.
What is the most common roofing term homeowners should know?
The most important term is "flashing." Flashing is the metal pieces installed at joints and changes on your roof: around chimneys, vents, walls, and valleys. Most roof leaks happen at flashing points, not in the middle of shingle fields. Understanding flashing helps you communicate with your contractor and spot potential problems early.
What does roof pitch mean?
Roof pitch is the steepness of your roof, expressed as a ratio of vertical rise to horizontal run. A 6/12 pitch means the roof rises 6 inches for every 12 inches of horizontal distance. Pitch affects which roofing materials can be used, how water drains, and the overall cost of your project. See our roof pitch guide for more.
What is the difference between a soffit and a fascia?
The fascia is the vertical board that runs along the lower edge of your roof, directly behind the gutter. The soffit is the horizontal underside panel that connects the fascia to the exterior wall. Together they enclose the eave area. Soffits usually contain ventilation openings that allow air into the attic, while the fascia provides the mounting surface for gutters.
What are architectural shingles vs. three-tab shingles?
Three-tab shingles are flat, single-layer shingles with uniform cutouts. Architectural shingles have multiple layers bonded together, creating a thicker, textured appearance. Architectural shingles are heavier, more wind-resistant, and last longer: usually 30 to 50 years vs. 15 to 25 years for three-tab. Most roof replacements today use architectural shingles.
What is roofing underlayment and why does it matter?
Underlayment is a water-resistant barrier installed directly on the roof deck before shingles go on top. It serves as a secondary defense against water if the outer material is damaged. There are two main types: felt (tar paper) and synthetic. Most maker warranties require specific underlayment products to remain valid.
What is a cool roof?
A cool roof reflects more sunlight and absorbs less heat than a standard roof. Cool roofs use reflective materials, coatings, or lighter colors to reduce surface heat. In California, Title 24 energy code requires cool roof materials on most re-roofing projects. Cool roofs lower cooling costs and extend the life of roofing materials.
What does EPDM stand for in roofing?
EPDM stands for Ethylene Propylene Diene Monomer. It is a synthetic rubber membrane used mostly on flat and low-slope commercial roofs. EPDM is known for its durability, flexibility, and UV resistance. It usually comes in large sheets that are glued or mechanically fastened, and can last 25 to 30 years.
How many roofing terms should I know before hiring a contractor?
Understanding 15 to 20 key terms (flashing, underlayment, decking, pitch, soffit, fascia, drip edge, ridge vent, warranty types) gives you enough vocabulary to follow your contractor's explanation and ask informed questions. A good contractor will explain terms as they go. See our contractor hiring guide for more.
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