TPO RubberThane

TPO RubberThane is a Kool Coats coating system for restoring serviceable thermoplastic polyolefin (TPO) roofs in the USA market. It places a TS-400 KwikShot Rubber base under a U-701 Aliphatic Urethane Topcoat.

The base layer accommodates movement at the roof surface, and the urethane finish is an abrasion-resistant protective topcoat. The system is used on TPO roofs with complex details or maintenance activity, and it is one of the liquid coatings for flat roofs in the Kool Coats range.

TPO stands for thermoplastic polyolefin. The membrane is cleaned and repaired, adhesion is tested, and the specified KwikShot rubber base is installed. The aliphatic urethane finish goes on after the required cure. The topcoat is identified by its full product name and approved schedule, since a product-code reference alone is ambiguous.

TS-400 KwikShot Rubber is a sprayable seam prep. It is sprayed on seams, laps, fasteners, flashings and transitions, which creates a flexible waterproof layer without fabric reinforcement. One roofer can prep 3,500 linear ft of seams in a single morning.

Surfaces must be sound and free of frost, dirt, grease, oil, loose nails and screws, and sharp protrusions. Loose dust and dirt are cleaned off by brushing or wiping with a clean, dry cloth, brush or broom. The product is not thinned, and it bonds to properly prepared roof surfaces.

Where the rubber is used on exterior vertical walls it must be top coated with a Kool Coats acrylic or urethane coating. It is not applied in high heat areas of 180 degrees F or more.

U-701 is a single-component, water-based, aliphatic polyurethane. It is supplied for protective use over compatible waterproofing membranes and is listed for exposed surfaces.

• Operating span for mechanical properties: -22 to 176 degrees F
• Frost resistance: -40 to 194 degrees F
• Water resistance: no leakage at a 3.3 ft water head over 24 hours
• Water vapor permeability: about 0.68 perms
• Shock temperature: 356 degrees F
• Tensile strength: over 1,450 psi

The finish is hydrophobic, has no chalking effect, and gives an easy-to-clean surface. Its volatile organic content is below 100 g/l.

The U-701 surface is clean, dry and sound, with moisture content no higher than 8%. Surface irregularities are smoothed, and loose pieces and grinding dust are removed. The surface carries a minimum 2% slope.

The topcoat is applied by roller, brush or airless spray in one or two layers. A layer cures 3 to 6 hours, and not more than 8 hours, before the next goes on. Rain resistance is reached in 4 hours, light pedestrian traffic is allowed after 18 to 24 hours, and the final cure takes 10 days.

Low temperatures retard cure, and high temperature speeds it up. High humidity, fog and dew also retard cure.

U-701 coverage is approximately 4.1 to 8.2 lb per 100 sq ft, in one or two coats. TS-400 coverage is 1 gallon per 100 sq ft at 30 mils wet film thickness. The rubber is supplied in tote, drum, 5 gallon and 1 gallon containers, and the urethane in 5, 3 and 1 gallon containers.

Kool Coats offers a 10-20 year Material Warranty on TS-400, with a 10-20 year Labor and Material Warranty available for a fee. TS-400 is cleaned from tools and spills with water. Maintenance guidance is an inspection at least twice a year and after severe weather.

The RubberThane system for TPO is a spray-applied KwikShot rubber base under a high-tensile aliphatic urethane topcoat. The rubber is listed at 1200% elongation. The system is spray-applied and rated for UV and chemical exposure.

The TS-400 rubber is water-based and low in VOCs. It is rated at 30 mils dry film thickness and 1200% elongation, with membrane strength of up to 1,540 psi. The manufacturer makes caulking and trowel grades. Gaps wider than 1/8 in are filled with the caulking grade before the rubber is sprayed over the seams and details.

U-701 is a water-based, low-VOC, single-component aliphatic polyurethane topcoat. It is white only and comes in a 5 gallon container. It protects exposed waterproofing membranes in light pedestrian traffic and service access areas over urethane systems.