Roof Maintenance Coating Systems

This guide covers proper application tips when spraying single component, moisture-cured urethane elastomeric coatings. Airless spray equipment is an effective method of application particularly on large areas and irregular or vertical surfaces. Gas powered spray equipment can also be used (consult with equipment manufacturer for recommendations). Air- atomized application is not recommended.
Personnel using these products should familiarize themselves with procedures for personal safety, workplace precautions, and equipment operation. Refer to Product Data Sheet, Material Safety Data Sheet, and General Instructions.

Climatic Conditions

1. Rain, fog, dew, frost, relative humidity above 90%, will adversely affect moisture cured urethane coatings, affectingadhesion and physical properties of the coating. Do not apply if any of these conditions exist or will exist within fivehours of application. The substrate must be dry at the time of application.
2. At temperatures below 60°F (16°C), store and maintain material temperature above 65°F (18°C) in the container.Spray application is not recommended below 50°F (10°C).
3. At temperatures above 80°F (27°C), reduce the application rate on vertical or irregular surfaces to prevent sags or runs.Do not apply at temperatures above 100°F (38°C).

Spray Equipment

Airless spray equipment generates very high fluid pressure. Spray equipment must be properly maintained and operated. Any misuse of spray equipment or accessories (such as over-pressurizing, modified parts, or worn or damaged parts) can result in serious bodily injury, fire, explosion, or property damage. Read and follow the equipment manufacturer’s instructions and recommendations.

1. Airless spray pump must have minimum 5,000 psi output pressure rating and adequate delivery volume to supportthe spray tip orifice, gallons per minute, rating. High-pressure airless sprayers with a higher maximum pressurecapability will allow spray application in cooler weather or by using spray hose lengths greater than 200 feet (60.96 m).

2. Spray Pump Recommendations:
(a.) Pump Ratio 45:1.
(b.) Hose 3⁄4” ID Hose first 100’ (30.48 m) with swivel connections and 1/2” ID hose for second 100’ (30.48m)
(c.) Pressure 5,000 psi.
(d.) Working pressure is 2,000 to 3,000 at the gun. Depending on equipment set-up, you may be able to spray the coating as low as 1,800 psi. Based on tip size, raise pressure to remove fingers in spray pattern.(e.) High-pressure fittings.
(f.) Input flow 100 psi.
(g.) Tip = .032 – .037 for an 8’’ pattern at 12’’ distance (20.32 cm pattern at 30.48 cm distance).
(h.) Recommended 12’’ extension with swivel tip.
( i.) Tip and pump sizes will change depending on temperature and pattern concerns.

Spraying Technique

1. Hold the spray gun perpendicular to the surface at a distance of 18” to 24” (46 cm to 62 cm) from the roof. Whiletriggering the spray gun, move it at a rate to produce the desired coating wet mil thickness without thin spots or“holidays”. Spray technique should include a “half lap” technique where each spray pass is overlapped 50% foruniform coverage. Check applied film thickness using a wet mil gauge. (32 wet mils per 100 sq. ft. (9.29 m2).
2. Using the 2,700-3,000 psi fluid pressure will provide a uniform spray pattern without fingering.
3. Allow a minimum of 24 hours cure time between coats for cure and solvent evaporation. Spray across roof, back-roll asneeded to ensure uniform coverage, then back-spray across the same area to complete application.

Spraying Precautions

1. Rope off the area within 150’ (46 m) of spray area.
2. Seal off ventilation intakes within the affected area.
3. Use windbreaks, where necessary, to confine spray mist and avoid damage to nearby surfaces due to overspray or drift.
4. Keep spectators and personnel away from spray area.

Clean Up

1. Clean airless spray equipment with Xylene thinner. Re-circulate thinner through pump supply, airless spray pump andspray hose to remove residual coating. Then flush with clean Xylene thinner.
2. Do not leave in airless spray system for more than one hour. Under certain conditions, it is possible for these coatingsto gel or harden inside the equipment.
3. For long-term storage, a final flush with mineral spirits is recommended.
4. For further details, consult with technical support or sales representative.

Protection Equipment

1. Use supplied air-breathing apparatus with full-face mask or hood during any spray application unless monitoringdemonstrates TDI exposure below OSHA permissible limits.
2. Fabric coveralls are recommended.
3. Impervious gloves are recommended.

Storage and Handling

1. Storage
(a.) Keep containers closed, store in a dry, cool place away from heat, sparks, open flame, and moisture.
(b.) Keep material stored above 65°F (18°C).
(c.) Open containers should be blanketed with dry nitrogen before resealing.

2. Mixing
(a.) Settling or separation may occur upon storage.
(b.) Mix material before using to assure uniform consistency. Use Jiffymixer for open head drums.
(c.) Ground container and equipment to prevent accumulation of static charge.