GAF Diathon^® Base Coat Roof Coating is an elastomeric acrylic coating used in a basecoat/topcoat system to build film thickness prior to application of a GAF Diathon top coat over spray polyurethane foam (SPF). GAF Diathon^® Base Coat Roof Coating is designed for easy application with conventional or airless spray equipment, as well as brush or roller.

Approved Substrates: New and existing Spray Polyurethane Foam (SPF).

Packaging Sizes:
5 gallon (19 liter) pail
55 gallon (208 liter) drum
275 gallon (1041 liter) tote

Standard Colors: Light Gray and Light Tan

APPLICATION INSTRUCTIONS

Substrate Preparation: Roof must have positive drainage, and be clean and dry with no trapped moisture. Repair damaged SPF, flashings, and penetrations. 

For previously coated SPF roofs, conduct test patches to verify adhesion of coating prior to start of work.

Mixing: Mix uniformly for a minimum of 3 minutes prior to use. Do NOT attempt to thin or self-tint.

Application: Apply to new polyurethane foam surfaces within 72 hours after final application, depending on climate and manufacturer (refer to foam manufacturer for more information). Apply by brush, roller, or airless sprayer evenly at the rates specified below. Do NOT apply more than 1.5 gallons per 100 ft² (6.1 L per 10 m²) in a single coat. Apply additional coats perpendicular to the previous coat once it is dry enough to walk on.

Total coverage is dependent on the substrate. See Limited Warranty on GAF Roof Coatings for complete coverage and restrictions.

STORAGE & SHELF LIFE

Product Storage Temperature: 50°F – 90°F (10°C – 32°C) Do NOT allow coating to freeze.

Shelf Life: 18 months from date of manufacture in unopened containers, if stored properly in a clean and well-ventilated area.

SAFETY & HANDLING

For specific information regarding safe handling of this material, please refer to the Safety Data Sheet (SDS).

LIMITATIONS & PRECAUTIONS

Application Air Temperature: Min. 50°F (10°C). Do NOT heat containers.

Application Surface Temperature: 50°F (10°C) and rising. Care should be taken when coating surfaces above 120°F.

Contact GAF Design Services if you have application questions.

Do NOT apply if rain, dew, fog, heavy moisture, condensation, or freezing temperatures are in the 8-hour forecast to ensure proper cure. Cool temperatures/high humidity may slow curing.