289 White Roof Sealant

Henry 289 White Roof Sealant, printed on its data sheet as HE289 White Roofing Sealant, is a white, elastomeric acrylic patching compound for repairing and preventing roof leaks before an acrylic reflective coating goes on. The data sheet's last revision date is 09/14/2011. The sealant is a water-based paste or mastic with a soft, easily troweled consistency, and it is brush grade. It belongs to the Henry roof coatings and sealants range, and it is a flat roof waterproofing accessory used under acrylic coatings.

The sealant is white only. It coats with white or tinted acrylic coatings, and it is applied by brush or trowel. It carries Florida approval and Miami-Dade approval marks.

• Consistency at 77 F: paste or mastic; soft, easily troweled.
• Base: water-based acrylic resins and mineral fibers.
• Color: white.
• Solids by weight: 55%.
• Specific gravity at 77 F (25 C): 1.39.
• Weight per gallon: 11.4 to 11.8 lbs.
• Maximum VOC: 50 g/l (0.42 lbs/gal).
• Flash point: above 212 F.
• Application temperature: 50 F and rising.
• Freezability: do not freeze.

The sealant meets or exceeds ASTM Specification C-920, Class 25. It does not bleed through reflective coatings, and it will not crack, craze or lose adhesion when applied as directed to a smooth, clean, sound roof surface. It skins over quickly and is cleaned up with soap and water.

The usage list for this sealant is as follows.

• Standard mineral surface cap sheet.
• Smooth-surface built-up roofing.
• SBS modified roofing.
• Previously coated asphalt roofs.
• Weathered metal roofs.
• Concrete and stucco parapet walls.

It may be applied to a dry or damp surface, but not a wet one. Concrete and masonry surfaces are dampened before application. It is not used with asphalt primer.

The product is ready to use and is not thinned or stirred. The surface is clean and free of dust, rust, residues and contaminants such as chalk, grease and wax. Rust and scale are removed from metal by wire brushing. Gravel, dust and dirt are swept away, and accumulated residue in low areas is scrubbed with detergent and rinsed.

Cracks, breaks, tears and holes are repaired by applying the sealant 1/8 inch to 1/4 inch thick with a 4 inch brush, a trowel or a putty knife. It can be applied over cured old roof cement. The sealant is worked into the crack or break and spread 2 inches to 4 inches beyond, with the edges feathered. If the damaged area is over 1/4 inch wide or 2 inches long, a layer of Henry #296 Polyester Repair Fabric is embedded between two heavy coats of the sealant, each at least 1/8 inch, extending 2 inches beyond the fabric. At splits caused by structural movement, the reinforced repair extends at least 6 inches beyond each end of the split. The sealant forms a skin and sets in 2 to 24 hours, depending on depth of fill and weather, before coating. Voids are filled with more sealant, which sets before coating.

Coverage is 12 1/2 square feet per gallon applied 1/8 inch thick. Application is on a warm, sunny day with a roof surface warm to the touch. It is not applied when air temperature is below 50 F (10 C) or when fog, rain or temperatures below 50 F (10 C) are possible within 48 to 72 hours. Relative humidity above 50% slows drying considerably. The sealant is not for use over shingles of any kind, rubber or plastic sheet roofing membranes or polyurethane foam roofing. On a gravel-surfaced roof, loose gravel is scraped away and the surface cleaned, and it is not applied over gravel. It is not stored above 120 F (49 C).

Product sizes are a 10.1 oz cartridge, 10.1, 10.3 and 11 oz sizes, a gallon (11.5 lb) and a 3.5 gallon pail (35 lb). Tools are cleaned with warm soapy water before the sealant dries, and dried film can be removed with lacquer thinner. Henry's limited warranty provides replacement of product proved defective within 12 months of purchase, if applied in accordance with Henry's written directions and with proof of purchase.

• Retail item number: HE289.
• Sizes: 10.1 oz cartridge, 1 gallon and 3.5 gallons.
• Cleanup: soap and water.