When Does a Roof Coating Make More Sense than a Roof Replacement?

Building owners have a lot to think about when selecting a roof for their commercial property. When it comes to commercial roofs, we have some information to help you understand what factors play a role in the roofing system's success, and its ability to protect the building, people and contents within it.1. ProductsThere are several different types of commercial roofing systems, and each has different benefits. A roofing professional can help building owners decide between the following roofing system types depending on the unique needs of the building:Single-ply: Single-ply membrane systems are the most popular commercial roofing material because single-ply is strong, durable, and provides robust protection against UV damage.Liquid-applied: Liquid-applied roofing systems are also strong and durable, and they're ideal for challenging roofs with a lot of equipment and penetrations. Ensuring flashing integrity and regular membrane cleaning can help extend the life of a liquid-applied roofing system.Modified-bitumen: A typical modified bitumen roofing system consists of two plies of roofing membrane. The membranes contain synthetic rubber which provides greater elongation than some other asphaltic systems. Modified-bitumen systems have a wide range of application methods, and can be hot-mopped, cold-applied, heat-welded or self-adhered.Built-up roofing: Built-up roofs are the oldest of the current roofing technology, and consist of melting bricks of hot asphalt in a large metal kettle and using mops to apply that asphalt in-between a multi-ply BUR system.It is recommended that all components of a roofing system are purchased from the same manufacturer. This helps ensure that the components are designed to work together. It also may make the system eligible for enhanced warranty or guarantee coverage from the manufacturer.2. EnergyThe rise of more stringent energy codes has increased the need for additional roof insulation and increased roof surface reflectivity. Increasing the amount of insulation in the roof and installing highly reflective roofing materials can help improve the energy efficiency of buildings.3. MaintenanceRegular roof maintenance may be required in order to keep your manufacturer's guarantee or warranty in effect.Maintenance programs can also help commercial building owners manage risk. Regular maintenance can help you address minor problems before they become expensive issues, which may ultimately help owners save money long-term.Maintenance staff should perform regularly scheduled roof inspections at all locations to ensure that the roof is still in good shape. Look for dents, tears, ponding water, or other signs of damage. Roof drains should be cleared regularly to ensure that water is allowed to drain unimpeded. Regular inspections and maintenance allow potential problems to be discovered early, before they cause other damage.Property maintenance companies and building owners can talk with manufacturers such as GAF to learn more about proper roof maintenance. Click here to get started.4. Warranty/GuaranteeA good warranty or guarantee program is one of the top reasons commercial building owners may choose a particular roofing system. Building owners want to know that they can count on the manufacturer to address any covered issues that may arise. Many roofing manufacturers offer warranties or guarantees for building owners that have no dollar limit on covered repair expenses.GAF offers several commercial roof system guarantees and warranties, ranging from 12 to 35 years of coverage, depending on the particular type of roofing system installed, how it is installed, and by whom. The Diamond Pledge NDL Roof Guarantee offers strong protection for commercial roofs—and for certain eligible systems, the coverage period can be extended by contracting with a GAF certified contractor* to provide maintenance throughout the roof's life. Additional requirements apply, see gaf.com for details.With proper maintenance, the right roofing system can provide protection for years to come.*Contractors enrolled in GAF certification programs are not employees or agents of GAF, and GAF does not control or otherwise supervise these independent businesses. Contractors may have agreed that they will use GAF roofing products, and may receive benefits, such as loyalty rewards points and discounts on marketing tools from GAF for participating in the program

Construction planning through to completion can be tricky to coordinate, especially within an urban area, which can present a range of complications. Building proximity, tall building heights, complex building structures, and densely populated areas are just a few challenges that can make it particularly difficult to consider traditionally heavy or large-sized materials when roofing or re-roofing a building.In addition to construction planning constraints, states such as California, New York, and others are adopting more stringent building codes to help alleviate the effect of urban heat islands.As property owners, architects, specifiers, and contractors are seeking new solutions to overcome these issues, the roofing materials industry is seeing increasing adoption of coatings and liquid membrane products that are easy to deliver and apply to the roof, while generating potential labor and installation savings during construction plus lower material costs for long-term maintenance.Benefits of Coatings for Urban ProjectsCoatings offer a distinct advantage in urban construction environments due in part to their mobility, ease of application, and potentially low environmental impact. At an average weight of 60 lbs. (27.2 kg) per 5-gallon (18.9 L) pail that can be carried by a handle, coatings solutions can ease transportation in ways that traditional roofing materials may not. Thanks to service elevators, coatings' advantages are often seen in busy metropolitan areas where using a crane or halting traffic may be expensive or otherwise challenging.Coatings also adhere to many existing roof materials, which can be helpful when restoring a structurally sound, low-slope roof that may have multiple surfaces, such as an asphaltic roof, a metal drip edge, and polyvinyl chloride (PVC) vent pipes.Coatings are manufactured to be "built on site," whether as just a coating with no reinforcement or through a layered approach, where fabric is embedded in the coating to create a reinforced liquid-applied membrane.The versatile application methods of liquid products and fabric rolls are a key benefit to urban construction projects. Many times, these products can be quickly and easily applied using brushes, rollers, or squeegees. These tools are relatively lightweight and easy to transport, and they don't require power or specialized equipment that may not travel well or can be disruptive to residents and neighbors — making them ideal for city construction in tight, crowded spaces.Additionally, with the build-on-site capability of liquid membranes and a lightweight fabric, it's possible to optimize a roof system to match any space. Liquid-applied products can seamlessly adhere to angles, making them an ideal solution for a roof with many details that need to be flashed or angles where a custom fit is needed, conforming to any detail to provide waterproofing protection.Coatings are also useful in maintaining and repairing roofs, which makes them a viable option for building owners and facility managers looking for a roof that can be easily maintained with similar materials to ensure proper adhesion and extend performance.Liquid-applied products can also meet the requirements of a more sustainable and environmentally conscious roofing solution. They may have the ability to restore a structurally sound roof without the need to tear off the existing roof. Additionally, many coatings are manufactured to comply with regulatory requirements, such as low volatile organic compounds (VOC) content, low or no biocides, or being zinc free (always make sure to check local building codes for applicable requirements).Types of Coatings for Urban ProjectsThere are many different technologies when it comes to roof coatings, and each has a unique advantage and offers a unique solution, depending on the needs of a project.Items to consider when selecting a coatings technology often include regulatory requirements and local VOC restrictions, weather conditions affecting the roof, the amount of foot traffic on the roof, and a range of other factors that may be unique to the roof.As with any project, it is important to ensure that each product meets or exceeds testing and certification requirements when selecting any coatings solutions, including the following:• Acrylic coatings are water-borne, typically have low VOCs and low odor, and can easily be applied or recoated in the future. Most acrylics are one-part products, meaning they are ready to use, and there is no need for mixing multiple components. Typically applied via brush, roller, or sprayer, acrylic coatings also offer easy cleanup.• Fluoropolymer (polyvinylidene difluoride, or PVDF) technology is a water-borne technology manufactured using Kynar Aquatec resin, which is based on Kynar 500 technology. The technology provides color stability, a strong solar reflectivity of lighter color coatings, and architectural or aesthetic value. This product is typically used only as a topcoat (over an acrylic basecoat) and on roofs where aesthetics are a primary concern.• Silicone coatings are moisture cured, have low odor, and can be applied easily. Offering a wide range of solutions to many roofs, silicone coatings are generally chosen for their high solids content. In particular, customers choose high-solids silicone coatings because they are suitable for roofs that pond water.• Urethane coatings, both single-component (1K) and two-component (2K), are solvent-borne, high-solids technologies that provide an excellent balance of tensile strength, elongation, and hardness. The 2K urethane products are specifically chosen when durability, dirt and mildew resistance, chemical resistance, weatherproofing, and high abrasion and impact resistance are needed.Combating Urban Heat IslandsThe urban heat island effect can best be described as what happens to urban areas as populations move into a central area — more pavement, fewer trees, more infrastructure, and more hardscape. There are many studies on the effects of urban heat islands, and while hard surfaces such as pavement play a large role, so do roof surfaces. This dynamic leads to higher temperatures in these areas, whereas their surrounding rural landscapes, which often have less pavement, more trees, and less infrastructure, typically see lower temperatures.To help mitigate this effect, coating roofs (and pavement) with lighter, more reflective colors will help lower roof temperatures.By coating an asphaltic roof with a white acrylic coating, one can greatly reduce the surface temperature. According to a 2010 article entitled, "Potential Benefits of Cool Roofs on Commercial Buildings," that reduction may be as much as 55 °F (30.6 °C) and may also result in significant savings in cooling energy. Cooling of the roof not only benefits the building owner but can also reduce the heat island effect in the area.ConclusionsWhether your need is easy delivery to an urban roof project, a creative roof design that will protect the building and provide a seamless detail, or a reflective roof solution to mitigate urban heat island effects, coatings and liquid membranes are a viable solution for you. With many different coatings technologies and manufacturers on the market, the decision can be challenging. To assist with your decision, ensure that you partner with a manufacturer who offers many solutions so you can find the one that is best suited for your project.To explore liquid-applied coatings solutions offered by GAF, click here.

When it comes to commercial roofing, the options are plentiful—but not every option is suited for every building. Each building has unique needs that factor into which types of roofing may be suitable for a given project. Here is an overview of what goes into a commercial roof as well as the material options available.1. The Roof DeckCommercial roof systems are installed over a roof deck. There are different types of roof decks, including:MetalWoodLightweight insulating concreteStandard concretePoured gypsumTectum decksThe roof deck serves as the substrate for a commercial low-slope roof. The additional layers of materials that are installed on top of the roof deck make up the roofing system.2. The Insulation and Cover BoardInsulation or cover board is often installed over the roof deck. Cover boards have insulating properties, can help provide protection against damage from impact or punctures, and can be used in a system that requires an ANSI/UL 790 Class A fire rating. (Check the UL directory for approved systems). They are also a common choice when roofing over the top of an existing roof.Insulation board comes in a variety of options. Based on the thickness of the board and the number of layers installed, the end result will deliver different R-values for the roof system and the building. The higher the R-value, the better the system works to keep heat from entering or exiting the building.3. The Finishing TouchesThe roof membrane or coating is typically installed over the insulation or cover board. There are several different types of roof membranes or coatings to choose from, depending upon the specific needs of the project and the owner's preferences.Single-Ply MembranesSingle-ply membranes are available in three different options:EPDM: Also known in the roofing industry as rubber roofing, EPDM has been in use since the 1960s. It's fairly easy to install and can be mechanically attached, adhered, or ballasted.TPO: TPO is a thermoplastic membrane that made its roofing debut in the 1980s. It has quickly grown to make up about 50% of the single-ply market. Available in an array of light colors with reflective properties, TPO is attractive to building owners interested in energy efficiency.PVC: PVC is a thermoplastic membrane introduced in the 1970s. It provides strong puncture resistance and can withstand exposure to many chemicals and greases. Weldable seams with bleed-out make it easy to tell when a weld was successful.AsphalticAsphalt roofing systems are among the oldest and most trusted kinds of roofing system. Two of the most popular include modified bitumen and built-up roofing (BUR).Modified bitumen: This type of roofing generally consists of a base sheet and a cap sheet and can have one or more ply sheets installed between. Depending on the style of the sheet, installation options vary from torching to hot mop applied to adhesive applied to self-adhered.BUR: As one of the oldest asphaltic roofing systems, BUR consists of layers or plies of asphaltic sheets that are installed using hot asphalt. Additional sheets or layers are added until it reaches the desired number of plies.Liquid AppliedLiquid Applied Coatings are becoming more popular as building owners look for solutions that can extend the life of a structurally sound roofing system and help increase time between tear-offs. Often referred to as coatings, there are multiple systems available featuring the following technologies:Acrylic coatings: These are exceptionally durable and ideal for coating over a variety of substrates. They offer reflectivity and excellent waterproofing protection.Silicone coatings: These coatings can protect against biological growth associated with ponding water, while also providing high reflectivity.Urethane coatings: These coatings are highly durable and provide strong resistance to physical impact and foot traffic.Fluoropolymer Resin coatings: PVDF coatings provide excellent flexibility with a tough finish that offers exceptional color stability. These coatings are often used for design work on roofs such as company logos.SEBS coatings: These thermoplastic coatings cure to form a monolithic rubber membrane. Their high flexibility can help withstand the expansion and contraction that may result from extreme temperature changes.GAF has solutions to meet the needs of any commercial roofing project. Visit the GAF commercial roofing resources page to learn more about the solutions available or contact your local GAF territory manager to get started with your next commercial roofing project.