Contractor spraying Hydrostop on roof

Premium Acrylic HydroStop® System

The HydroStop® roof coating system is an affordable solution to extend the life of structurally sound metal roofs.

A fully-reinforced roof coating system assembly that meets FM 4470*

components of hydropstop system

Count on the HydroStop® System for recover, reroof, and new roof applications.

This easy-to-apply roof system offers excellent adhesion to a variety of substrates, including metal, structural concrete, TPO, PVC, Hypalon®, EPDM, polyiso, gypsum roof board, and asphaltic roofs, for a combination of reinforcement and toughness.
*Refer to FM RoofNav for Actual assemblies

Products in the HydroStop® System

Premium Acrylic Hydrostop Top Coat

GAF Premium Acrylic HydroStop® Top Coat

A professional grade, water-based, acrylic elastomeric coating that is part of the GAF Premium Acrylic HydroStop® Coating System. Get documents
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Premium Acrylic Hydrostop Base Coat

GAF Premium Acrylic HydroStop® Base Coat

A water-based acrylic base coat. Used in conjunction with the Premium Acrylic HydroStop® Top Coat and the Premium Fabric, it creates the GAF Premium Acrylic HydroStop® System. Get documents
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Learn about warranty and guarantee coverage

Warranty info

HydroStop® System Case Studies

5 simple steps to metal roof restoration

with the HydroStop® System

1. Qualify and prep the roof

  • Ensure the roof is clean, dry, and tight
  • Conduct adhesion test to ensure proper coating adhesion
  • Make any necessary repairs to the sheet metal and secure or replace all loose or missing fasteners
  • Power wash roof using GAF Cleaning Concentrate
  • Install sheet metal crickets behind rooftop units, if needed

2. Prime rusty areas

Roofing contractor treating seams

3. Treat seams and fasteners

  • Seal horizontal seams, ridges and rake edges using a roof brush with GAF Premium Brush-Grade Acrylic Flashing and 12” GAF Premium Fabric (Three-course at a rate of 30 linear feet per gallon)
  • Vertical seams: Seal with GAF Premium Brush-Grade Acrylic Flashing
  • Fasteners: Encapsulate all fasteners using GAF Premium Brush-Grade Flashing
Roof contractor detailing penetrations

4. Detail penetrations

Apply GAF Acrylic Base Coat to help improve adhesion of the GAF Acrylic Top Coat and mitigate any asphaltic bleed-through- Apply Acrylic Base Coat per the specifications for a 10/15 year warranty, can be brushed, rolled, or spray-applied
Roofing contractor coating roof with HydroStop

5. Coat the roof

Download the complete installation steps


Additional Resources

Use these links to connect with the products and people you need to get the job done.

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Coatings support

Call us at 1-855-478-5041 or email us below
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