A plain-language reference guide to materials, systems, warranties, and key commercial roofing terminology.

A–C

Asphalt Shingles
Common residential roofing material made from fiberglass and asphalt, known for affordability and ease of installation.

Ballast
Loose stone or gravel placed on top of a roof membrane to hold it in place, protect it from UV exposure, and provide weight against wind uplift.

Base Sheet
The first layer of a built-up or modified bitumen roofing system installed over insulation or deck to provide a smooth, stable surface for subsequent layers.

Built-Up Roofing (BUR)
A traditional commercial system made by alternating layers of bitumen (asphalt or coal tar) and reinforcing fabrics (plies), topped with gravel or a reflective coating.

Cant Strip
An angled strip used where the roof deck meets vertical walls or curbs to create a smooth transition, improving membrane adhesion and reducing stress.

D–F

Commercial Roof Coating
Protective liquid membrane applied to existing roofs to extend their lifespan and improve waterproofing.

Commercial Roof Maintenance
Ongoing inspections, repairs, and preventative care to extend the life of a commercial roof system.

Commercial Roof Repair Fixing leaks, damage, or wear on commercial roofing systems to restore functionality.

Commercial Roof Replacement Removing and installing a new commercial roof when the existing system is beyond repair or expired.

Commercial Roof Restoration
The process of repairing and recoating an existing roof system to extend its life, improve waterproofing, and enhance energy efficiency without full replacement.

Coatings (Roof Coatings)
Liquid-applied membranes used to extend roof life and improve energy efficiency. Common types include acrylic, silicone, polyurethane, elastomeric, and asphalt-based coatings.

Cool Roof
A reflective roofing system designed to reflect more sunlight and absorb less heat, lowering building cooling costs.

Cover Board
A rigid board installed between the insulation and membrane to improve durability and fire resistance.

Crickets (or Saddles)
Small peaked structures built into flat roof systems to divert water toward drains and away from HVAC curbs or skylights.

G–I

J–L

M–O

Mechanically Attached
A membrane attachment method using screws and plates to fasten the roof system to the deck.

Metal Edge
A flashing component installed at roof perimeters to protect the membrane and provide a clean finish.

Modified Bitumen
A rolled asphalt-based membrane reinforced with polyester or fiberglass, often installed using heat, adhesives, or cold-applied methods.

NDL (No Dollar Limit) Warranty
A commercial roofing warranty that covers the full cost of repair or replacement, regardless of cost, if the system fails within the coverage terms. Usually offered by manufacturers on high-end systems.

Overburden
Any material or structure (e.g., solar panels, pavers, rooftop gardens) installed on top of a roofing system.

P–R

Penetration
Any object that passes through the roof deck or membrane, such as vents, pipes, or skylights, requiring flashing to prevent leaks.

Polyurethane Coating
A durable liquid-applied roof coating known for high tensile strength, flexibility, and chemical resistance.

Roof Coating
A protective layer applied over existing roofs to restore waterproofing and reflectivity, extending service life.

Roof Repair
The process of addressing leaks, damage, or deterioration in roofing systems to maintain performance and integrity.

Roof Replacement
Complete removal and reinstallation of the roofing system when repairs are insufficient or the system has failed.

Roof Maintenance
Routine inspections and repairs designed to prolong roof life and prevent costly damage or failures.

R-Value
A measure of a material’s resistance to heat flow. The higher the R-value, the better the material insulates and reduces heat transfer, improving energy efficiency in buildings.

S–U

SPF (Spray Polyurethane Foam)
A closed-cell foam sprayed onto roofs that expands and hardens, creating a seamless, insulating waterproof layer.

Scupper
An outlet in the side of a building’s parapet wall that allows rainwater to drain from a flat roof.

Silicone Coating
A UV-stable and waterproof liquid coating used to restore and protect flat roofs, especially in ponding areas.

TPO Coating
A thermoplastic polyolefin-based coating applied to restore aged TPO membranes, improving reflectivity and waterproofing.

Urethane Coating
A tough, flexible liquid-applied coating known for excellent chemical and abrasion resistance, commonly used in commercial roof restoration.

V–Z

Vapor Barrier
A layer installed to prevent moisture from passing from the interior of a building into the roofing system.

Walk Pads
Protective mats installed on commercial roofs to provide safe access for maintenance and prevent membrane damage from foot traffic.