Frequently Asked Questions

Good weather is important to a successful coating installation. Specific installation temperatures vary by product, but our popular acrylic coatings require temperatures of 50⁰ F and rising. All substrates must be dry, so morning dew must have dried and the weather forecast must include no rain for 24 hours to help assure the newly installed coating dries properly.

No. GAF does not recommend coating asphaltic roof shingles.

Generally speaking, water-based acrylic coatings can be recoated with other water-based acrylic coatings, such as GAF’s Roofshield, Roof Mate or Hydrostop® products. Acrylic coatings can NOT be sprayed over silicone coatings. Additionally, asphaltic membranes coated with fibered aluminum coatings are not acceptable

substrates and the fibered aluminum coating must be removed prior to installing any GAF liquid-applied roofing product.

Roof substrates must be clean, completely dry, and free from any foreign matter. Examine the substrate to receive new roofing and conduct test patches to verify adhesion of coating prior to start of work. Check for any damaged roof membranes, including all flashings and penetrations, and repair before coating application commences. Priming of the substrate may be required.

Kynar®-finished metal panels and coping require special preparation prior to recoating.

That depends, remember surfaces must be clean and dry. Any rust, or residual sealants (including plastic roofing cement) should be removed and/or encapsulated to assure proper adhesion. Small areas of rust may be pretreated and encapsulated prior to application of coatings. See the attached Cut Specification for compatible product options.

The Cut specification contains application instructions (in the chart below) which gives you both a "wet mil" application rate and a "Gallons per sq." (100 sq. feet) measurement.

It’s possible (easy) to install too much material (and run out) and too little material (and risk not obtaining the desired roof protection). Below are two best practice tips:

Use a different color base coat and top Installing white on white makes it hard to tell if you have adequate coverage and an even application.
Using a wet mil gauge to measure the amount of coating as you are

Both are acceptable application methods. Because rollers may absorb coating, be sure to plan for extra material needs.

Primers

• On smooth surfaces 3/8" nap
• On rough surfaces ½" to ¾" nap

Coatings

• 1"- 1 ¼" for all coating products

That depends on the substrate and the condition of the seams. All flashing requirements for seams and penetrations are included in the attached Cut Specification.

Yes, for best performance and to be eligible for coverage under GAF’s limited warranty only use coatings during the applicable shelf life set forth on the product label or container (usually between 12-18 months from the date of manufacture, provided the materials have been properly stored). Remember, improper storage can shorten product shelf life

Always dispose of roof coatings (contents/container) in accordance with local/regional/national/international regulations. For more information on GAF’s coating products, see the Safety Data Sheets available on GAF.com.