Coating and Restoration Glossary

A water-based roof coating that provides UV protection and reflectivity. Cost-effective but degrades in ponding water. Typical lifespan: 7-12 years.

A pattern of deep interconnected cracks in asphalt-based roofing that resembles alligator skin. Indicates the asphalt binder has oxidized and lost flexibility.

Atactic Polypropylene modified asphalt membrane. APP gives the membrane plastic-like properties and is typically torch-applied. Common in warm climates including the Gulf Coast.

The first layer of a multi-coat roof coating system. In two-part systems, the base coat (often polyurethane) provides adhesion and impact resistance, while the top coat provides UV and weather protection.

Raised bubble-like formations in a roofing membrane or coating caused by trapped moisture, gases, or poor adhesion. Small isolated blisters are repairable; widespread blistering indicates systemic problems.

A multi-ply roofing system made of alternating layers of bitumen and reinforcing fabric, often topped with gravel. Common on older Gulf Coast commercial buildings.

The measurement of a coating's thickness in mils (1 mil = 1/1000 of an inch). Wet mils are measured during application; dry mils are the final cured thickness. A credit card is approximately 30 mils thick.

A roofing system that reflects more sunlight and absorbs less heat than a standard roof. Reflective coatings can transform an existing roof into a cool roof, reducing cooling costs by 10-30%.

The amount of roof area that can be covered by one gallon of coating at the specified thickness. Varies by product and application method. Typically 50-100 sqft per gallon depending on chemistry and thickness.

The thickness of a coating after it has fully cured. Calculated as: wet mils x solids percentage. This is the measurement that determines coating performance and warranty compliance.

A property meaning 'rubber-like' or 'stretchy.' Describes coatings that can stretch and return to shape. Not a specific chemistry — elastomeric coatings can be silicone-based, acrylic-based, or polyurethane-based. Always ask which base chemistry.

Ethylene Propylene Diene Monomer — a synthetic rubber roofing membrane. Black in color, known for durability and flexibility. Requires EPDM-specific primer before coating; standard primers will not adhere.

A polyester or fiberglass mesh embedded in coating at seams, penetrations, and detail areas to bridge gaps, strengthen transitions, and prevent cracking at stress points.

An open gap at a roofing seam where the membrane edge has lifted and curled, resembling a fish's mouth. Indicates seam adhesion failure and allows water entry.

A non-destructive survey using an infrared camera to detect moisture trapped beneath a roof membrane. Wet insulation retains heat differently than dry, creating visible temperature differences. Critical step before any coating project.

The waterproof layer of a roofing system. Can be a single sheet (TPO, EPDM) or multiple layers (modified bitumen, BUR). The membrane is what keeps water out of the building.

A roofing membrane made of asphalt modified with polymers (SBS or APP) for improved flexibility and durability. Often granule-surfaced. Common on Gulf Coast commercial buildings.

A survey method using a nuclear gauge to detect moisture in roofing insulation. More precise than infrared in some conditions but requires specialized equipment and licensing.

A two-component coating system offering excellent abrasion and impact resistance but poor UV resistance. Typically used as a base coat under a UV-resistant top coat like silicone or acrylic.

Standing water that remains on a roof surface 48+ hours after the last rainfall. The 48-hour standard is used by most coating manufacturers and building codes. Only silicone coatings tolerate ponding water.

High-pressure water cleaning of a roof surface before coating. Removes dirt, biological growth, and degraded material. Essential for coating adhesion — coating applied to a dirty surface bonds to the dirt, not the membrane.

A bonding layer applied between the existing roof substrate and the new coating. Creates adhesion between incompatible surfaces. Substrate-specific — using the wrong primer is a leading cause of coating failure, especially on EPDM.

Polyvinylidene fluoride — a high-performance paint finish used on metal roofing panels. Known for exceptional color retention and weather resistance. Kynar and Hylar are brand names for PVDF finishes.

Applying a new coating layer over an existing coating that has reached the end of its service life. Part of the normal maintenance cycle for coated roofs. Typically costs 50-65% of the original coating.

A treatment that restores flexibility to aging asphalt shingles by reintroducing oils that evaporate over time. Extends shingle life by approximately 3-5 years per application. Not a coating and not a replacement.

The process of extending a roof's life through coating or other treatments rather than full replacement. Includes inspection, preparation, repair, and coating application.

A liquid-applied membrane that adds waterproofing and UV protection to an existing roof substrate. Available in multiple chemistries (silicone, acrylic, polyurethane) with different performance characteristics.

A branded shingle rejuvenation treatment using soy-based bio-oil to restore flexibility to aging asphalt shingles. Claims up to 15 years of extended life; independent assessment suggests 3-5 years per application.

Styrene-Butadiene-Styrene modified asphalt membrane. The SBS polymer gives the membrane rubber-like flexibility. More common than APP in colder climates but used throughout the Gulf Coast.

The process of reinforcing existing roof seams with sealant and fabric reinforcement before coating. Most roof leaks occur at seams, not in the field — seam treatment is a critical preparation step.

A moisture-cure coating that is unaffected by ponding water. Excellent UV resistance. The only coating chemistry suitable for roofs with standing water. Typical lifespan: 10-15 years.

Silicone-Modified Polyester — a paint finish commonly used on pre-finished metal roofing. Less durable than PVDF but more cost-effective. Typical color retention: 15-25 years.

A measure of a roof's ability to reject solar heat, combining reflectance and thermal emittance. Scale of 0 (standard black surface) to 100+ (ideal reflective surface). White silicone coating typically scores 104 SRI.

A monolithic roofing system sprayed as a liquid that expands into rigid foam, providing both waterproofing and insulation (R-6.5 per inch). Requires a protective coating to prevent UV degradation.

The existing roof surface that receives a coating. Common substrates include TPO, EPDM, modified bitumen, BUR, metal, and SPF. Each substrate requires specific preparation and primer compatibility.

A measure of how efficiently a surface radiates absorbed heat. High emittance (0.8-0.9) means the surface releases heat quickly rather than transferring it into the building. Important for cool roof performance.

The final layer of a coating system that provides UV protection, weather resistance, and the visible surface. In multi-coat systems, applied over the base coat after proper cure time.

Thermoplastic Polyolefin — a single-ply roofing membrane, typically white, with heat-welded seams. Common on Gulf Coast commercial buildings. Coatable when membrane is structurally sound.

The thickness of a coating as it is being applied, before it cures and loses solvents/water. Measured with a wet mil gauge during application. Dry mil thickness = wet mils x solids percentage.