SMAA-1P-7xE — All-acrylic reinforced roof system

SMAA-1P-7xE is a one-ply all-acrylic Western Colloid roof system. The title line is Upgrade Smooth Surface / Cap Sheet / Single Ply, followed by 1 Ply Polyester Reinforced - Acrylic Surface. The system is applied cold and water based over existing BUR, Mod Bit and PVC single ply roofing. It has very low odor and a single polyester ply set in ElastaHyde, finished with a reflective elastomeric surface. EPDM, spray polyurethane foam and TPO membranes are covered by separate specific specifications. The assembly is also named for Energy Star and California Title 24, with LEED (USGBC), Factory Mutual Standard 4470 Class 1 and U.L. Class A.

Five layers make up the system, with approximate dry weights per 100 sq. ft.

• Base coat of ElastaHyde: 3 gallons, 21 lb
• Polyester fabric: 1 ply, 2.5 lb
• Top coat of ElastaHyde: 1.5 gallons, 10.5 lb
• Reflective surface coating of ElastaHyde White Acrylic: 1.5 gallons, 10.5 lb
• Second reflective surface coating of ElastaHyde White Acrylic: 1.0 gallon, 7.0 lb

Total system dry weight is 51.5 lb and approximate total dry thickness is 74 mils.

The membrane is a single coat of ElastaHyde at 3 gallons per 100 sq. ft. with one full-width polyester ply embedded wet, starting at the low edge. The ply is lightly broomed to saturation and ends 2 inches above the cant. Pipe flashings, cones, exposed metal joints and flanges are then treated with #800 Elastic Cement and fabric in a three course method. The reflective coating is applied at 4 gallons per 100 sq. ft. in a three coat application, with each coat about a third of the total and laid at right angles to the one before.

Areas around drains and scuppers receive an extra ply of polyester set in ElastaHyde. So do valleys, waterways and any location where water ponds for more than 48 hours. The extra ply reaches 12 inches beyond the ponding area, or far enough to clear the drain sump, and is set into ElastaHyde at 3 gallons per 100 sq. ft. It goes on after the membrane and before the final coatings.

The roof membrane is sound and watertight, free of loose gravel, dirt and dust, and washed in full. Over smooth BUR, asphalt emulsion or non-granulated modified bitumen, #970 A2A primer is applied at 1/2 gallon per 100 sq. ft. Small splits get the #800 three course repair of 5 gallons then 4 gallons per 100 sq. ft. around a ply of polyester.

ElastaHyde is applied by roller, brush or spray, and high pressure airless spray gives the strongest results. A Quick Set formulation exists. Coverage runs 75 to 100 sq. ft. per gallon per coat, and totals of 2 1/2 to 6 gallons per 100 sq. ft. are used depending on specification and surface. Application temperature is 50 degrees F minimum and 100 degrees F maximum ambient. It dries in one hour at 100 sq. ft. per gallon at 70 degrees F and 50 percent relative humidity. Minimum dry thickness is 20 mils and recommended is 24 or more, and VOC is 10 actual and 20 regulatory. #800 Elastic Cement is white or black, and the black speeds drying in cold weather. This polyester reinforced liquid-applied roof is cleaned up with soap and warm water.

Work on this water based system begins only when the temperature is at least 55 degrees F and rising. Where a preparation or repair step has no water based material in it, it may be carried out ahead of bad weather.

• Polyester fabric: Western Colloid 2.75 ounce firm or 3.0 ounce soft stitchbonded polyester, supplied in various widths, used to reinforce asphalt emulsion, acrylic coating and flashing materials
• #8000 All Weather Elastic Cement: a solvent-based white sealant that sets the flange of a new or replaced pipe jack, and a stated alternative to #800 where more immediate water resistance is needed
• #850 SWS walkway coating: a water based coating of acrylic resins and binders with an aggregate that forms a textured, non-slip surface with high abrasion resistance
• #970 A2A Bonding Primer: a clear acrylic primer that improves adhesion of acrylic coatings to smooth BUR, emulsion and non-granulated modified bitumen

• Solar reflectivity, initial: 84 percent (ASTM C1549)
• Thermal emittance, initial: 89 percent (ASTM C1371)
• SRI: 106 initial and 93 aged (ASTM E1980-01)
• Flammability: non-flammable wet, Class A dry (U.L. 790 and ASTM E108)
• 1000 hour xenon arc UV exposure: Pass (ASTM D4798)

• Elongation: above 250 percent initially and above 175 percent after weathering (ASTM D2370)
• Tensile strength: above 250 psi (ASTM D2370)
• Wet adhesion over emulsion: above 10 pli, dry adhesion above 17 pli (ASTM D903)
• Tear resistance: above 100 lbf/in (ASTM D624)
• Low temperature flexibility: Pass at 15 degrees F, 1/2 inch (ASTM D522)
• Permeance: below 15 (ASTM D1653)
• Water swelling: below 20 percent (ASTM D471)
• Fungi resistance: no growth (ASTM G21)
• Dirt pick-up resistance: very good

Three colors are made: white as the standard, California Tan and Platinum Gray, plus custom colors. The Cool Roof Rating Council lists the coating. California Title 24 is met by white, California Tan and Platinum Gray, and those are the colors named for ENERGY STAR. Packaging runs from 5-gallon pails and 55-gallon drums to totes and bulk tankers.

Existing spray polyurethane foam roofs, conventional and modified built-up roofs, and the topcoats of Western Colloid FARR and metal roof systems are the uses named. QS, the Quick Set formulation, handles application when damp or rainy weather is expected before drying is complete. Wood shingles and untreated wood are surfaces it is not recommended over, and ponding for over 72 hours without reinforcement is also excluded.