Modified Bitumen Acrylic

Modified Bitumen Acrylic is a Kool Coats coating system for modified bitumen roofs that pairs a sprayable rubber seam treatment with an acrylic topcoat. It sits in the Modified Bitumen family and is listed for the USA market. Where the silicone system for this substrate starts with an asphalt primer, this system starts with seam and detail preparation and finishes with a water-based acrylic.

The two products are KwikShot TS-400 sprayable rubber seam prep and TopShot EDGE TS-505 advanced acrylic topcoat. The assembly is one of the flat roof waterproofing coating systems in the Kool Coats line.

The cap sheet is prepared and repaired first. KwikShot rubber is then applied at laps, penetrations and transitions, and the selected TopShot acrylic completes the assembly. The detail build and the field build are kept separate in the application schedule.

The KwikShot base is a spray-applied rubber with 1200% elongation that seals seams, penetrations and transitions without fabric. The acrylic system is intended for sloped modified bitumen roofs with solid drainage.

KwikShot is a water-based, non-silicone liquid rubber made for fabric-free seam preparation in commercial acrylic and urethane roof systems. It is sprayed on seams, laps, fasteners, flashings and transitions to form a flexible waterproof layer.

Listed performance is 100% waterproofing at 30 mils dry film thickness with up to 1200% elongation. One roofer is listed as prepping 3,500 linear feet of seams in a single morning.

• Coverage rate: 1 gallon per 100 sq ft at 30 mils wet film thickness
• Packaging: tote, drum, 5 gallon and 1 gallon
• Not thinned
• Cleaned up with water; unused product stored in the original container, tightly sealed

Surfaces must be sound and free of frost, dirt, grease, oil, loose nails and screws, and sharp protrusions. Loose dust and dirt are cleared with a clean, dry cloth, brush or broom. The product goes on between 50 F and 90 F, on a warm dry surface that is at least 5 F above the dew point and rising.

Application tools are a nylon or polyester brush, a 3/8 inch to 1/2 inch nap nylon or polyester roller, or airless spray equipment.

• Minimum airless sprayer: tip orifice 0.015, flow rate 0.34 GPM, maximum working pressure 3,000 psi, 1/4 inch hose
• Maximum airless sprayer: tip orifice 0.065, maximum flow rate 4.0 GPM, maximum working pressure 4,000 psi, 3/8 inch hose reduced to 1/4 inch
• Not applied if the temperature is expected to fall below 32 F within 24 hours, or over wet substrates
• Not applied in high heat areas of 180 F or more
• Test patch for adhesion before proceeding
• Topcoated with a Kool Coats acrylic or urethane coating for all exterior vertical wall exposures

TopShot EDGE is an elastomeric acrylic coating made with high solids content and enhanced elongation. It is described for 15-plus year systems and for commercial restorations needing a high-build, one-pass coating. The formulation has reduced filler content.

• Solids by volume: 52%; solids by weight: 62%
• Weight per gallon: 10.8 lbs
• Tensile strength: 300 psi
• Elongation: 360% nominal
• Tear resistance: 105 lbs/in
• Hardness: 65 Shore A
• Cure time: 24 to 48 hours at 77 F and 50% humidity
• VOC: less than 50 g/L
• Application temperature: 50 F to 100 F
• Service temperature of the cured film: 15 F to 180 F
• Packaging: tote, drum, 5 gallon and 1 gallon

Surfaces to be coated are clean and dry. Chemical cleaners, power washing or priming may be needed for adhesion on some substrates. Damaged membranes, flashings and penetration points are repaired and sealed first, and low areas that hold water are repaired.

The coating is mixed well to a uniform consistency and color, with a power mixer for quantities over one gallon. It is not thinned, because thinners or additives alter the intended performance and void all warranties. It goes on with standard airless equipment capable of 2000 to 3000 psi, or a medium nap roller, and a brush is used for small touch-up work.

It is not applied below 40 F or when rain is expected within four hours, and lower temperatures can affect cure. The coating can dry in 1 to 4 hours depending on temperature and humidity, and a subsequent coat goes on as soon as the previous one can be walked on.

TopShot equipment and overspray are cleaned with water. Tools can be cleaned with lukewarm water and soap, followed by an isopropanol, acetone or Simple Green rinse recirculated through lines and gun. Mineral spirits, xylene, toluene, and VMP and naphtha solvents are not used. Shelf life is 12 months from date of manufacture, unopened, between 40 F and 100 F.

Kool Coats lists a 10 to 20 year Material Warranty for both products, with a 10 to 20 year Labor and Material Warranty available for a fee. The warranty is non-transferable and is given solely to the original purchaser.