Gravel BUR RubberThane

Gravel BUR RubberThane is a Kool Coats coating system for restoring sound gravel-surfaced built-up roofs (BUR) in the USA market. A TS-400 KwikShot Rubber base is covered with a U-701 Aliphatic Urethane Topcoat.

The rubber base follows the uneven surface of the roof, and the urethane finish serves as the protective topcoat for exposed service areas and maintenance activity. The system belongs to the Gravel BUR family and is one of the coatings for low-slope built-up roofs in the Kool Coats range.

Loose gravel is vacuumed off, the roof is repaired, and the specified KwikShot rubber base is installed across the prepared surface. The selected aliphatic urethane coating is the finish. The urethane topcoat is identified from the written assembly schedule, since the product code is also close to that of a silicone mastic.

The base is KwikShot rubber with 1200% elongation, topped with an aliphatic urethane. The system is listed for Class 4 hail protection and chemical resistance, and for movement, foot traffic and standing water. It is intended for environments with traffic and UV exposure.

Loose gravel is vacuumed off the BUR surface before the base goes on. The U-701 topcoat is applied on a surface with a minimum slope of 2%. Where the slope is lower, cementitious mortar, resin mortar or similar material is used to form it before the waterproofing coating goes on.

U-701 is a single-component, water-based, aliphatic polyurethane. It cures to a UV- and color-stable surface with no chalking effect.

• Solar reflectance index (SRI): 113
• Rain resistance time: 4 hours
• Light pedestrian traffic: 18 to 24 hours after application
• Final cure time: 10 days
• Pull-off adhesion: over 65 psi
• Shore A hardness: over 80
• Elongation at break: 250%

The finish is slippery when wet. Suitable aggregates sprinkled onto the still-wet coating produce an anti-slip surface.

The surface is clean, dry and sound, with moisture content not above 8%. Old, loose coatings, dirt, fats, oils, organic substances and dust are removed by grinding machine. The surface irregularities are smoothed. New concrete dries for at least 28 days.

U-701 is stirred well and applied by roller, brush or airless spray in one or two layers. The coating is not applied below 40 degrees F or when dew, rain or frost is imminent in the next 48 hours. Between 40 and 95 degrees F is the range for application and cure. Cleanup is with soap and water.

TS-400 is a water-based, non-silicone liquid rubber. It bonds to properly prepared roof surfaces and ties into Kool Coats acrylic and urethane systems. At 30 mils dry film thickness it is rated 100% waterproofing with elongation up to 1200%, and 1 gallon covers 100 sq ft at 30 mils wet film thickness.

• Containers: tote, drum, 5 gallon and 1 gallon
• Application temperature: 50 to 90 degrees F
• Application equipment: nylon or polyester brush, 3/8 to 1/2 in nap roller, or airless sprayer
• Not applied over wet substrates

U-701 comes in 5, 3 and 1 gallon containers, stored 12 months at 41 to 86 degrees F in original unopened containers. The roof is inspected at least twice a year, and straight away after severe weather. The Kool Coats 10-20 year Material Warranty on TS-400 and a fee-based 10-20 year Labor and Material Warranty apply to original purchasers only.