National Coatings Blog

A Metal Roof Case Study - Hundley Hardware Co.

Posted by Nicole Gale on Thu, Nov 05, 2015 @ 11:00 AM

Metal Roof Case Study
Hundley Hardware Co. 


Size: 10,300 Square Feet
Location: San Francisco, California
Applicator: D.C. Taylor Company
Consultant: Independent Roofing Consultants (IRC)

Challenge - Aging, Leaking Metal Roof
  • Aged metal roof with several leaks
  • Rusted sections
  • Occupied business
  • Custom colors needed
  • Multiple roof levels
Solution - AcryShield® Restoration System  
  • Superior waterproofing and reinforced seams
  • RustShield A120 primers used after rust was removed for protection against future rust growth
  • No business disruptions or closures during application
  • Custom tinted coating color matched to existing building scheme
  • Watertight, leak-free hundley_hardware32-resized-219

E.M. Hundley Hardware Company's building was an aging metal roof system, over twenty years old, that was revealing inconsistent nuisance leaks to the interior sales floor. IRC specified a National Coatings' AcryShield Roof Restoration System consisting of a localized, reinforced, two-coat, 100% acrylic elastomeric custom color coating system with polyester fabric reinforcement at all metal panel end joints.

"National Coatings makes this approach feasible not only with excellent coating products but also with the wide range of accessory products from rust-inhibitive primers to individual butyl caps to encapsulate the existing panel fasterners."

- Project Manager, Mr. Rob Worthing

FREE GUIDE: Metal Roof Coating Systems



Tags: Metal Roof, sealer for metal

Looking for a Metal Roof Sealer to Achieve Excellent Waterproofing?

Posted by Nicole Gale on Thu, Aug 06, 2015 @ 11:30 AM
metal_before metal_after
Whether you are installing a brand new metal roof or restoring an aged one, you will need to establish adequate protection against water penetration.
Metal roofs are installed by attaching individual panels to one another. These panels are snapped together and fastened to the roof deck with rubber grommets. For a newly constructed metal roof, a metal roof sealer is required. Typically butyl seam tape is positioned over the joints and seams between the metal panels and butyl caps are placed over all nails and fasteners to ensure proper sealant.

FREE GUIDE: Metal Roof Coating SystemsIn the case of a metal roof restoration job, the seams, joints, fasteners and nails are the areas that are most prone to degradation allowing for water penetration. These areas need to be thoroughly re-sealed with a new metal roof sealer – butyl tape, butyl caps, and AcryFlex for detail areas that are unable to be sealed with either the butyl tape or caps. Once the metal roof sealers have been installed and all rust has been either removed or primed with a rust-inhibitive primer, such as RustShield, a base coat is applied with the option to embed custom reinforced polyester fabric in areas needing extra strength and durability. Lastly, a topcoat is applied over the metal roof surface leaving you with a fully restored, UV protected, watertight roof membrane.

What is Butyl Tape?

Butyl tape is a 4-inch wide, high tensile strength, polyester-reinforced, butyl rubber sealant tape for sealing edges and seams on metal roof panels.

What are Butyl Caps?

Butyl caps are round disks consisting of a tenaciously adhering butyl rubber sealant topped with a reinforcing polyester surface.

Benefits of Butyl Tape and Caps:

  • Extremely easy to apply
  • Instant waterproofing
  • Superior adhesion to metal roofing
  • Long-term durability
  • Excellent flexibility over a wide temperature range

What is AcryFlex?

AcryFlex is a premium quality, water-based, elastomeric, acrylic sealant engineered for long-term flexibility, adhesion and weather resistance. AcryFlex is excellent for application on metal roofing and sealing around joints and flashings.

Benefits of AcryFlex Sealant:

  • Superior adhesion to metal roofing
  • Long-term durability
  • Excellent flexibility over a wide temperature range
  • Non-flammable
  • Safe
  • Easy to Use

For more information on restoring aged metal roofing, download our FREE guide to Metal Roof Restoration or our Full Line Brochure. Below are links to our other individual substrate brochures:


Download our FREE Roof Coating Systems Benefits Brochure

Tags: Metal Roof, sealer for metal, metal sealant