National Coatings Blog

Maintaining your PVC Roof with Elastomeric Roof Coatings

Posted by Nicole Gale on Tue, Jul 28, 2015 @ 11:00 AM

UC_Davis_DormsPVC roofs are an excellent roofing option as they provide superior waterproofing and fire retardant properties. Unfortunately, these roofing membranes experience degradation and loss of plasticizers due to their chemical makeup. These single-ply membranes need to be maintained in order for long standing success. Using an elastomeric roof coating on top of the PVC to protect the membrane from early degradation is an excellent solution.

PVC roofing membranes are made of two sheets of thermoplastic film with a reinforced woven scrim between the two layers. These layers are held together using a single polymer. This polymer when exposed to sunlight and solar radiation (as all roofs are exposed to) begins to deteriorate and break down causing chalking, loss of adhesion within the membrane, loss of waterproofing capabilities and an overall premature aging of the membrane. These membranes become brittle and shrink, causing flexibility issues for the PVC membrane when the roof system expands and contracts due to normal temperature fluxuation. This is especially an issue in low temperatures climates. The shrinkage adds additional stress to the seams and fasteners holding the single ply membrane together, eventually causing roof failures.

Learn More About Coating Over  Aged  Single-PliesThe good news is elastomeric roof coatings are excellent at extending the life of an aged and failing PVC roof membrane. (Check out our case histories for proven success.) Installing a roof coating system for maintaining a PVC roof protects the PVC from the harmful sunlight and solar radiation. The elastomeric roof coatings are able to shield the PVC membrane from premature deterioration and chalking while correcting the already damaged areas. The roof coatings fill the voids and cracks created from deterioration with their superior adhesion capabilities.  The newly coated and restored PVC membrane now has the ability to provide the needed flexibility it originally possessed in order to move with the building during normal and extreme temperature changes.

Once the PVC roof is fully coated with the elastomeric roof coating system, the restored roof not only is watertight once again but also has renewed reflectivity, to lower energy consumption costs on cooling the interior of the building. The roofing membrane is no longer held together by seams and fasteners, instead, it is 100% seamless and monolithic, covering, sealing and protecting every inch of the roof top including areas around pipes, walls, rooftop equipment, and more. The elastomeric roof coatings are spray applied allowing every area to be filled, sealed, and watertight, even those hard to reach areas. 

The AcryShield Roof Management System (ARM) uses the highest quality elastomeric roof coatings available. This system has the capability of preserving and enhancing failing PVC roof membranes quickly, safely and cost effectively. You can avoid a costly roof tear-off and keep your business open as usual during installation. Contact us today for more information on our ARM System and Single-Ply Roofing options.

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Tags: Single-Ply Roof Coatings, Singleply Roof Coating Systems, pvc roofing, restoring PVC

Case Study: Direct Adhesion to Failing TPO Roof without Primers or Etching Rinse

Posted by Nicole Gale on Thu, Jun 11, 2015 @ 11:00 AM

Case Study Using AcryShield A502
Westinghouse Drive

Size: approximately 85,400 SF
Location: Fremont, CA
Contractor: Just Leaks, Inc.
System: National Coatings AcryShield® Roof Management System

Challenge: Failing TPO Roof

  • To extend the life of the existing TPO membrane.
  • Install a coating system that does not require a costly tear-off.
  • Stop existing leaks.

Solution: AcryShield® Roof Management System

  • Opportunity to reinforce trouble spots like drains, penetrations and waterways with polyester reinforcing fabric.
  • The system added many more years of service life to the existing roof membrane.

Learn More About Coating Over  Aged  Single-Plies "One of our best jobs for the year was on Westinghouse Drive in Fremont, CA where we restored an old TPO roof system. The building owner was convinced he needed to tear off the old TPO system and install a new one. National Coatings was able to provide us with case studies demonstrating that a restored TPO roof would result in a more robust and less expensive roof system. The AcryShield A502 had perfect adhesion to the failing TPO. We also avoided the exposure of a torn off roof on a 93,000 square foot building. Thanks so much to Tom Absher (NCC Sales Rep) and Missy DeLaTorre (NCC Customer Service and Business Development Manager)!" - Scott Siemer, President of Just Leaks, Inc.




Preserve Existing Single-Ply without Primers Click Here to Learn More!

Tags: Single-Ply Roof Coatings, Coating directly over TPO, TPO Roof Coating, Singleply Roof Coating Systems

Direct Adhesion for Hard to Coat Single-Ply Roofing Membranes

Posted by Nicole Gale on Tue, Jun 09, 2015 @ 11:00 AM

National Coatings has the unique ability to address the difficulties and failures that aged single-ply roofing experiences. Most roof coatings require caustic primers, acid etching agents, or high VOC solvents that need to be rinsed off and sometimes collected for disposal, adding additional cost to a roof life extension project. NCC's products have the unique ability to coat to single-ply roofing membranes without the need to use any of these harmful products. Our state of the art single-ply coating systems adhere directly to single-ply substrates providing a monolithic membrane without any of the seams that can be prone to failure. Coating restorations do no count as a new roof under most building codes, eliminating the need for periodic and costly tear-off's. This process allows for a truly sustainable roofing system by performing coating maintenance every 10 years.

AcryPly_Acrylic_Diagram_-_A502_eliminatedWhat's our secret? The AcryShield® A502 base coat! This single-ply base coat is the industry leader, ultra low VOC, high performance base coat for hard to coat surfaces such as Hypalon®, TPO, EPDM, and PVC roofing. A502 base coat eliminates the need for costly roof replacement and provides unique AcryLock technology to tenaciously adhere directly to EPDM, TPO and Hypalon without the need for additional primers or an etching rinse. A502 also provides an additional layer of waterproofing, superior adhesion, and resistance to ponded water.

FREE GUIDE: Single-Ply Roof Coating Systems

  • Lower project cost and higher job efficiencies
  • Special work place safety requirements are reduced or eliminated
  • Safer work conditions
  • Elimination of need to capture caustic contaminated water as required by some municipalities
  • Prolonged Roof Life
  • Reduced Life Cycle Costs
  • Sustainable Roofing
  • Seamless Waterproofing
  • Fully-Adhered Installation
  • Acrylic Durability

UL 790 Class A Rating   

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Factory Mutual Standard 4470 for Class 1 Fire, Windstorm, & Hail Classification

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 ICC-ES ESR-2140

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California State Fire Marshall

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ASTM D6083 Technical Data




Typical Result




Theoretical Coverage


66 sq. ft/gal

Wet Adhesion - Hypalon (pli)

2 Minimum


Wet Adhesion – TPO (pli)

2 Minimum


Wet Adhesion – EPDM (pli)

2 Minimum


Volume Solids (%)

> 50

54 ± 2

Weight Solids (%)

> 60

67.7 ± 2

Weight per gallon


11.88 lbs

Viscosity (KU)


110 ± 10

Drying Time (hrs)


4-8 hours*

*Drying time is dependent on temperature & humidity

ACRYSHIELD A502 is for industrial/commercial applications only.  These suggestions and data are based on information we believe to be reliable.  They are offered in good faith, but without guarantee, as conditions and methods of use are beyond our control. Click here to view our full Product Data Sheet on AcryShiled A502 

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Tags: Single-Ply Roof Coatings, Coating directly over TPO, Coating directly over EPDM, Coating Directly over Hypalon, TPO Roof Coating, TPO Roofing System, Singleply Roof Coating Systems