Plain English definitions of roofing terms — written for South Florida homeowners by Oscar Gonzalez, Miami Roofing Consultant.
The value of your roof after depreciation is subtracted. If your roof is 15 years old and has a 20-year lifespan, ACV pays only a fraction of replacement cost. Most older Miami roofs get ACV settlements unless you have RCV coverage.
A flat piece of metal installed where a vertical surface meets a sloped roof — such as where a wall meets the roof. Common on Miami homes with dormers or chimneys.
The most affordable roofing material. Made of fiberglass mat coated with asphalt and mineral granules. Popular for investment properties in South Florida due to lower upfront cost.
The system of intake and exhaust vents that allows air to flow through your attic. Critical in Miami's heat — poor ventilation shortens roof life significantly.
Metal or rubberized material installed at the base of roof penetrations like chimneys and vents to prevent water intrusion. A common source of leaks when it fails.
A flat roofing system made of multiple layers of asphalt and reinforcing fabric. Common on older commercial buildings in Miami. Being replaced by TPO and modified bitumen systems.
When wind lifts and removes roofing material from the structure. A major concern in South Florida during hurricane season. Proper installation and HVHZ-rated materials reduce blow-off risk.
When shingles or roofing material span an area without full contact with the decking underneath. Creates weak points that can fail under wind pressure.
The top layer of a modified bitumen flat roof system. Provides weather protection and UV resistance. Common on South Florida flat roofs.
Flexible sealant applied around roof penetrations, flashings and joints to prevent water infiltration. Requires regular inspection in Miami's heat and UV environment.
Metal pieces installed around a chimney where it meets the roof to prevent leaks. One of the most common leak points on Miami homes with chimneys.
The highest fire resistance rating for roofing materials. Required by most South Florida building codes. Tile, metal and most asphalt shingles qualify.
A roof valley where shingles from both sides overlap and cover the valley metal. Provides a clean look but requires precise installation.
Meeting the minimum standards set by the Florida Building Code. All permitted roofing work in Miami-Dade must comply with local amendments to the FBC.
Metal flashing embedded into a wall or chimney that overlaps base flashing. Part of a two-piece flashing system that allows for expansion and contraction.
A small peaked structure built behind a chimney or other obstruction to redirect water away. Required on wider chimneys in South Florida to prevent ponding.
The permanent weight a roof structure must support — including the roofing material itself. Tile roofs have much higher dead loads than shingle or metal, requiring proper structural support.
The structural surface, usually plywood or OSB, that roofing materials are attached to. In Miami, deck condition is carefully inspected — damaged decking must be replaced before re-roofing.
The reduction in value of your roof based on age and condition. Insurance companies use depreciation to calculate ACV payments. Understanding this is critical when filing a roof claim in Florida.
A roofed structure that projects from a sloping roof, usually containing a window. Creates complex flashing requirements that are common sources of leaks.
The vertical pipe that carries water from gutters down to the ground. Proper downspout placement is important in Miami to direct water away from the foundation.
An L-shaped metal strip installed at the roof edges to direct water away from the fascia and into the gutters. Required by Florida Building Code on all new roofs.
The lower edge of a roof that overhangs the wall. In South Florida, eave design affects how well a roof handles wind-driven rain during storms.
Ethylene Propylene Diene Monomer — a durable rubber roofing membrane used on flat roofs. Less common in Miami than TPO due to heat absorption issues.
The portion of a shingle visible after installation. Proper exposure is critical for water shedding and wind resistance in South Florida.
The board running along the lower edge of the roof that gutters attach to. In South Florida's humidity, wood fascia is often replaced with aluminum or composite during re-roofing.
The statewide building code governing all construction in Florida including roofing. Miami-Dade County has additional amendments due to its High Velocity Hurricane Zone designation.
A layer of asphalt-saturated felt installed between the decking and roofing material. Provides a secondary water barrier. In Miami, heavier 30-pound felt or synthetic underlayment is preferred.
The main area of a roof, excluding edges, ridges and valleys. Most roofing material quantities are calculated based on field area.
Thin metal pieces installed at roof transitions and penetrations to prevent water intrusion. One of the most critical components of any South Florida roof — failing flashing is a leading cause of leaks.
A roof with minimal pitch, typically less than 2:12. Common on commercial buildings and modern homes in Miami. Requires specific waterproofing systems like TPO, modified bitumen or EPDM.
State certification that a roofing product meets Florida Building Code requirements. Required for all roofing materials used in Florida. Check the approval number before any roof installation.
The triangular wall section at the end of a pitched roof. Gable ends are vulnerable to wind uplift in hurricanes — Miami-Dade requires special bracing for gable roofs in the HVHZ.
The mineral particles embedded in the surface of asphalt shingles. Granule loss is a sign of aging shingles and a common trigger for insurance inspections in Florida.
Channels installed at the eaves to collect and direct rainwater. Important in South Florida where heavy rain events can dump several inches in minutes.
A roof where all sides slope downward from a central ridge. Hip roofs perform better in high winds than gable roofs, making them common in South Florida new construction.
A designation covering Miami-Dade and Broward Counties requiring stricter building standards due to hurricane risk. All roofing materials and installation methods must meet HVHZ requirements — products must have a Miami-Dade NOA.
Metal connectors that tie roof rafters to wall framing. Required by code in South Florida to prevent roof uplift during hurricanes. Inspectors check these during re-roofing permits.
A self-adhering waterproof membrane installed in vulnerable areas of the roof. While designed for ice dams in northern states, it's used in Miami at valleys, eaves and around penetrations for extra waterproofing.
A formal request to your homeowner's insurance for payment to repair or replace a damaged roof. In Florida, claims must be filed within 3 years of damage. Documentation and proper inspection are critical.
The overlap of one roofing material over another. Proper lap measurements are critical for wind resistance and waterproofing in South Florida.
A waterproof membrane installed at vulnerable areas to provide additional protection against water infiltration. Required in certain locations under Florida Building Code.
A roof with a pitch between 2:12 and 4:12. Requires different materials than steep-slope roofs. Common on additions and older Miami homes.
Roofing made from steel, aluminum or copper panels. The best long-term option for South Florida's climate — resistant to hurricanes, mold, and UV. Lifespan of 40-70 years. Higher upfront cost but lower lifetime cost.
Notice of Acceptance issued by Miami-Dade County's product control division. The most rigorous product certification in the US — if a product has a Miami-Dade NOA it's approved for use in the HVHZ.
A flat roofing system made from asphalt modified with rubber or plastic polymers. Common on South Florida flat roofs — more durable than traditional built-up roofing.
Any material that prevents water vapor from penetrating the roof assembly. Critical in South Florida's humid climate to prevent mold and rot in the roof structure.
See Miami-Dade NOA. The product approval number required for all roofing materials installed in Miami-Dade and Broward Counties.
The specified pattern and frequency of nails used to secure roofing material. In the HVHZ, enhanced nailing patterns are required to resist hurricane-force winds.
A roof valley where metal flashing is exposed between the roofing materials on each side. Allows for better water flow and easier maintenance than closed valleys.
Engineered wood panels commonly used as roof decking. Less moisture-resistant than plywood — a concern in South Florida. Many contractors prefer plywood for Miami re-roofing projects.
The portion of the roof that extends beyond the exterior wall. Wider overhangs provide better protection from South Florida's sun and rain but require proper engineering for wind resistance.
An official approval required before replacing or significantly repairing a roof in Miami-Dade and Broward Counties. Permits ensure work meets code, protect homeowners legally, and affect insurance premiums. Never let a contractor skip permits.
The steepness of a roof measured as rise over run (e.g. 4:12 means 4 inches of rise for every 12 inches of horizontal run). Affects material choice, cost and wind performance.
The preferred decking material for South Florida re-roofing. More moisture-resistant than OSB and better suited for the humidity and rain Miami experiences.
Water that remains on a flat or low-slope roof more than 48 hours after rain. A serious problem that accelerates roofing material deterioration and can cause structural damage.
The Florida state approval number confirming a roofing product meets FBC requirements. Ask your contractor for the product approval numbers of all materials being installed on your roof.
The structural wood members that support the roof deck and covering. In South Florida, rafters must be properly connected to wall framing with hurricane straps.
Insurance coverage that pays the full cost to replace your roof with a similar one regardless of age. Far better than ACV coverage for Florida homeowners — always choose RCV if available.
Installing new roofing over existing material or after tear-off. In Miami-Dade, re-roofing requires a permit and inspections. A second layer of shingles is generally not permitted.
The highest horizontal line of a roof where two slopes meet. Ridge caps are installed here to seal the joint and are critical for wind resistance.
A ventilation strip installed along the roof ridge to allow hot air to escape from the attic. Important for energy efficiency and roof longevity in Miami's heat.
See Decking. The structural surface that roofing materials are attached to.
A unit of measurement equal to 100 square feet of roof area. Roofing materials are priced and ordered by the square. A typical Miami home has 20-30 squares of roof area.
A peel-and-stick waterproofing layer applied to the roof deck. Provides superior water resistance compared to felt underlayment. Required in certain areas of South Florida roofs under the FBC.
See Decking. The structural panels (plywood or OSB) that form the base of the roof system.
See Pitch. The angle of the roof surface.
The underside of the roof overhang. In South Florida, vented soffits allow air to enter the attic. Damaged soffits are a common entry point for water and pests.
A metal roofing system with raised interlocking seams running vertically up the roof. Excellent wind resistance and no exposed fasteners — one of the best options for South Florida.
Individual pieces of metal flashing used where a roof meets a vertical wall. Installed in steps alongside each course of shingles. Critical at roof-to-wall transitions.
Roof damage caused by wind, hail, rain or falling debris during a storm. In South Florida, storm damage is the most common reason for insurance claims and roof replacement.
The surface to which roofing materials are applied — typically the roof deck or underlayment.
A modern alternative to felt underlayment made from polypropylene or polyethylene. More durable, lighter and more moisture-resistant than felt — increasingly required in South Florida.
The removal of existing roofing material down to the deck before installing new roofing. Required in most Miami-Dade re-roofing projects. Adds cost but ensures proper inspection of the deck.
Roofing made from concrete or clay tiles. The most popular roofing type in South Florida due to durability, aesthetics and performance in the Florida climate. Lifespan of 30-50 years.
A single-ply white roofing membrane widely used on flat roofs in South Florida. Reflects heat, is energy efficient and resistant to UV, ozone and chemical exposure. The most popular flat roofing system in Miami.
Pre-engineered triangular structural framework that supports the roof. Most newer South Florida homes use trusses rather than traditional rafter framing.
A secondary water-resistant barrier installed between the roof deck and the roofing material. Required on all roofs in Florida — type and thickness requirements vary by roof pitch and location.
A roof's ability to withstand wind forces trying to lift it from the structure. Critical in South Florida — HVHZ requires specific uplift resistance ratings for all roofing assemblies.
The internal angle formed where two roof slopes meet. Valleys channel large amounts of water and are a common source of leaks if not properly flashed.
A material that resists the passage of water vapor. Important in South Florida's humid climate to prevent condensation within the roof assembly.
The system allowing air to flow through the attic space. Proper ventilation extends roof life, reduces energy costs and prevents moisture buildup in Miami's heat and humidity.
A formal inspection documenting a home's wind resistance features including roof shape, decking attachment, roof covering and opening protection. Can significantly reduce homeowner's insurance premiums in Florida.
The force exerted by wind trying to lift roofing material or the entire roof structure. HVHZ requires roofing systems to meet strict wind uplift resistance ratings — critical in Miami's hurricane environment.
Oscar Gonzalez explains everything in plain English — free inspection, no pressure.