National Coatings Blog

Asphalt Roof Coating Systems Can Prevent a Roof Tear-off & Save Money

Posted by Nicole Gale on Tue, Aug 05, 2014 @ 12:00 PM

Asphalt roof coatings are excellent for restoring aged or failing asphalt, BUR (Built-up Roofing) or Mod Bit (modified bitumen) roofing substrates. These coatings provide two valuable qualities – avoid a roof replacement and gain an energy efficient roofing system. 

asphalt-before-coatingLet’s discuss the first benefit – an asphalt roof coating system allows you to avoid a roof tear-off or roof replacement indefinitely. These asphalt coating systems fully restore your existing roof membrane to a new roof without the cost and time a traditional roof replacement or roof tear-off would take. There are no landfill fees, no additional waste removal stages, and no business closures. The asphalt roof coating system is spray applied directly over your existing roof membrane creating a monolithic, seamless roofing substrate.  With the use of the AcryShield A400 acrylic, elastomeric roof coating, your asphalt roof will benefit from advanced bleed-blocking properties and prevention of early roof degradation. The AcryShield base coats provide excellent waterproofing, superior adhesion, and resistance to ponded water. These systems are renewable allowing you to restore your roof every 10-15 years, avoiding a roof tear-off forever.

asphalt-coatedSecondly, they save you money by cutting down on your energy usage. The AcryShield topcoats provide industry leading UV protection, longevity and brightness to your roof. Your existing roof is transformed into a brand-new roof membrane that prevents a majority of the heat from the sun from being absorbed into the building. The white roof coating reflects the heat away from the roof lowering the surface temperature of the roof and the inside temperature of the building. This provides a substantial temperature difference from the original black asphaltic surface. After the National Coatings' Cool Roof was installed we definitely noticed a difference in building temperature. It's not a marginal difference, either. It is between 15-20 degrees cooler inside the warehouse and store." - Jerry Moore, Facilities Director at Harbor Freight Tools

These asphalt coating systems can be applied as a roof maintenance system for localized reinforcement and added UV protection to lower energy consumption, or as a newly constructed roof to give your dark asphalt roof a white roof coating for energy savings and also as a roof restoration system to fully restore your aged building providing you with extra insulation and/or structural enhancements with added energy efficiency. To learn more, download our FREE Asphalt Roof Coating System brochure for additional information.

Asphalt Roof Coatings

Tags: Asphalt Roof Membrane, Asphalt Coatings, Asphalt roof coating, coating asphalt

Roof Coatings - Different Classes of Coatings

Posted by Nicole Gale on Thu, Jul 24, 2014 @ 11:34 AM

roof coatingsClasses of Coatings
Roof coatings can be classified into three types:  solvent, water-based, and 100 percent solids.  Solvent systems are those containing an organic solvent as carrier for the coating.  In this case, solvent evaporation causes the coating to form the membrane on the roof.  Water-based coatings employ water as this carrier.  The third class, albeit less common, is the solvent-free coating where two liquid components are premixed in a specially designed airless spray unit; a chemical reaction causes some of these two-part coatings to dry almost immediately.  Each of these three coating classes has specific advantages and disadvantages relating to the type and presence or absence of solvent.

Solvent Coatings
Coatings which employ organic solvents can be applied over a wide range of temperatures, including cold or marginal weather conditions.  Moreover, they will dry quickly under conditions of high humidity since the rate of solvent evaporation is not related to relative humidity.  These advantages are offset to some degree, however, because they contain large percentages of usually flammable, and sometimes highly toxic, organic solvents.

Additionally, many of these coatings are required to carry the D.O.T. classified "red label" associated with low flammability flash point.  This means the applicator must exercise care and prudent handling procedures when transporting, storing, and applying such coatings.  Also, since these systems contain organic solvents which may soften certain asphalt and other conventional roofing materials, they may cause "bleed through" problems or, even worse, permanent damage to the old roofing substrate.  Rooftop air intakes must be masked to prevent vapors from entering the HVAC and ventilation systems.

Finally, when using these materials, additional solvent is required to clean the application equipment after use.

Water-Based Coatings
In contrast, water-based coatings eliminate the flammability and potential toxicity hazards associated with solvent systems since they use water-rather than solvent-as the carrier.  Additionally, the equipment used can be easily cleaned with soap and water, and their potential for "bleed through" is significantly lower because they do not contain solvents.  Since water is an inexpensive solvent, cost is usually lower than solvent-based coatings.

The chief limitation of water-based coatings is the range of atmospheric conditions conducive to application.  First, they should not be applied at temperatures too close to freezing because the rate of water evaporation becomes so slow they may not dry properly.  Normal low cut-off point for application of these coatings is 50 degrees F.  Second, they should not be applied when rain or inclement weather is imminent.

Considerable progress in narrowing this application conditions gap between solvent- and water-based coatings has been made with a recent introduction to the marketplace of systems with "quick set" properties.  National Coatings AcryShield A600 and A640 have this property and can adequately withstand heavy dew or light rain shortly after application.

100 Percent Solids Coatings
The third, less common type of roof coating consists of 100 percent solids.  Since these coatings contain virtually no solvents, they do not possess the limitations of the water- or solvent-based coatings.  However, they do require special application equipment and are extremely sensitive to changes in application temperature as their ability to form a durable, long-lasting membrane is dependent on proper mixing ratios of the two components and reaction temperature.  If incorrect, the coating may not adequately cure or may, possibly, gel prematurely, thus preventing the protective membrane from forming properly.

Acrylic Coatings
Acrylic roof coatings take advantage of the inherent durability of acrylics, and can be designed to be very elastic and flexible over a wide temperature range for a relatively modest cost.  In addition, they are supplied as either water- or solvent-based products, although specialized acrylic coatings are available for roofs experiencing ponded water conditions.

For more information on roof coatings – download our FREE Brochure!
Looking for specific information on restoring a roofing substrate? Download one of our specific brochures:

Commercial Roofing Contractors

Cool Roof


Tags: Roof Coating Membranes, Roof Coating Systems, Roof Coating, Single-Ply Roof Coatings, SPF Roof Coatings, Asphalt Coatings, Hypalon Roof Coating, Roof Coatings for EPDM, TPO Roof Coating

Do you have an aged or failing Asphalt roof that you want to restore?

Posted by Nicole Gale on Thu, May 22, 2014 @ 01:00 PM

Keep your business open as usual, avoid a costly and timely tear-off
using the AcryShield A400 for asphaltic roof surfaces


AcryShield A400

A400 top coat has unique asphalt bleed-blocking properties making it particularly suited for a top coat over asphalt. The AcryShield A400 was developed specifically for areas in warm to moderate climates where temperatures do not drop below 0°F.

A400 contains ZERO VOC's and provides longevity and brightness with superior dirt pick-up resistance and protection against biological attack such as algae and mold. AcryShield A400 has excellent tensile strength, elongation, wet adhesion and weatherability, it exceeds all of the ASTM D6083 requirements except for low temperature flexibility. 

Asphalt Roof Coatings

  • Seamless Waterproofing
  • Fully-Adhered Installation
  • Asphalt Bleed Blocking
  • Acrylic Durability
  • Energy Savings
  • Prolonged Roof Life
  • Reduced Life Cycle Costs
  • Renewable
  • ZERO VOC's
  • As an ENERGY STAR® Partner - Product in white and sand, meets the ENERGY STAR® guidelines for energy efficiency.
  • UL 790 Class A Rating
  • ICC-ES ESR-2140
  • California State Fire Marshall
  • CRRC Rated
    • Prod ID 0626-0001 (white)
    • Prod ID 0626-0007 (sand)
  • California Title 24 Compliant
  • Florida Power and Light Approved

Tags: Roof Coating Membranes, Roof Coating Systems, Roof Coating, Asphalt Roof Membrane, Asphalt Coatings