Acrylic Reinforced Coating System Concrete

Acrylic Reinforced Coating System Concrete is a Metacrylics assembly for concrete roof decks and surfaces. The drawing is sheet A-08, titled Concrete Fully Reinforced Acrylic Restoration System, dated 09-25-17. The finish chemistry is acrylic.

The drawing's detail note names expansion joints and horizontal and vertical transitions among the items sealed and reinforced.

From the existing concrete roof upward, the drawing shows a primer, an acrylic base coat, polyester fabric, a second acrylic base coat and Metacrylics topcoats.

Note 1 states that the primer is not needed when Acrylic Clear Base is the acrylic base for the polyester fabric. Note 2 states that all rooftop penetrations, drains, scuppers, flashings, skylights, expansion joints, horizontal and vertical transitions and perimeter edge metal are sealed and reinforced by 3-coursing with Metacrylics Acrylic Gel and polyester fabric.

Roof & Tile Primer is the primer data sheet for this system. It is a clear, water-based acrylic primer, white as a liquid and clear when dry. Concrete and stone are among its listed substrates. New concrete must be fully cured for 30 to 60 days before application.

It is applied at 0.25 to 1 gallon per 100 sq. ft. by spray or roller and dries in 1 to 4 hours. Properties: solids 16 to 20, pH 7 to 8, viscosity 1500 to 6000 cps, density 1.03 g/cm3, anionic dispersion, film elongation at break 700 percent, glass transition temperature 17 degrees C and water absorption 5 percent. It contains no zinc oxide.

Peel adhesion for Acrylic Gray Base, Acrylic Gel and Acrylic Clear Base is reported on concrete: 6.3 average pounds per linear inch by ASTM C836. Acrylic Gray Base and Acrylic Gel report 0.016 perms at 81 mils dry film thickness (ASTM D1653), and Acrylic Clear Base reports 0.016 perms at 63 mils.

Wind uplift for each is 105 PSF under Section 6 of ANSI A58.1, and fire resistance is Class A under ASTM E-108 and UL Standard 790 at 1,400 degrees F flame and 1,050 ft per minute wind velocity.

The Acrylic Gray Base surface preparation text states that surfaces are clean, dry and free of dust, dirt and oily residues, and that new concrete must be fully cured.

Acrylic Gray Base is a gray, water-based acrylic elastomeric coating. Spray rates are 2 to 3 gallons per 100 sq. ft. under the embedded fabric and 2 gallons per 100 sq. ft. over it. It weighs 12.1 pounds per gallon and has 67.9 percent solids by weight.

Acrylic Clear Base dries clear and can be used as a self-priming basecoat. Its tensile elongation is 434 percent and its Shore A hardness is 41.

Extreme Performance Plus Acrylic White is the topcoat data sheet. Elongation at break by ASTM D412 (Die C) is 521.12 percent. Solar reflectance is 0.90 and thermal emittance 0.88 by CRRC C-1371. Weight is 11.3 pounds per gallon and VOC is 27.5 grams per liter.

Acrylic Gel is the mastic for details. Its VOC is 0.14 grams per liter, its weight 11.5 pounds per gallon, and its CRRC solar reflectance 0.87 with thermal emittance 0.90. Stitchbond Polyester Fabric T272 has a tensile of 57.1 lbs, elongation of 61.65 percent and Mullen burst of 176.8 lbs. T272 rolls are 40 inches wide by 324 feet long.

The manufacturer's applications page lists one surface entry as Tile or concrete surface. Its tile system layers are a prepared tile surface, Roof & Tile Primer and Roof & Tile Sealer, and the sealer comes in clear plus more than 30 colors. The spec book gives tile systems of 5 to 10 years on pages 41 to 43. Each begins with a pressure wash, and the primer and sealer are not applied to damp surfaces or when moisture is expected within 24 hours, because the sealer turns cloudy and white until it dries.

• Roof & Tile Primer: 0.5 gallons per square, cured 1 to 4 hours
• Clear Roof & Tile Sealer, 5-year: 1.25 gallons per square in two coats of 0.625 gallon
• Color Roof & Tile Sealer, 5-year: 1.5 gallons per square in two coats of 0.75 gallon
• Color Roof & Tile Sealer, 10-year: 2 gallons per square in two coats of 1 gallon

Acrylic Clear Base is white as a liquid and dries clear and tacky. It must be protected from sunlight with a Metacrylics acrylic topcoat. It is used as a self-priming basecoat or as a primer for adhesion to existing surfaces, and for exterior and below-grade waterproofing. Tensile strength is 276 psi at 81 mils including 10 mil fabric, elongation is 434 percent average, hardness is Shore A 41 and there is no flash at 200 degrees F. Chemical resistance shows no effect from 1 percent sodium hydroxide, with some softening and spotting from gasoline and some spotting from lubricating oil.

Acrylic Gel had a 2,000 hour weatherometer result of no cracking, crazing or erosion, with slight chalking. Its low temperature flexibility passes at 1 inch and minus 40 degrees F by ASTM C836, and its flash point is above 200 degrees F. LEED points are available for heat island effect, and the colors are white, gray and clear.

T272 has the highest Mullen burst of the soft grades at 176.8 lbs, while W201 has the highest tensile at 75 lbs. T326 elongates 25.8 percent, the lowest of the four, and W201 elongates 42.9 percent. Trapezoid tear is 16.1 lbs for T272, 13.2 lbs for T325, 14.2 lbs for T326 and 13.4 lbs for W201.

The spec book detail sequences that apply around concrete roof edges and openings are as follows. Edge flashings, nosings and gravel stops are primed and given a 3-course of 6 to 9 inch fabric and gel, 3 inches onto horizontal flashing and 3 inches onto the vertical outside wall. Wood blocks are lifted, the area is coated with gel or acrylic base and white, and the block is replaced when dry. Gutters are pressure washed, primed and 3-coursed with gel and fabric over all joints, and Peel & Coat is not used on any gutter.

The build of primer, reinforced base coats and reflective topcoat is the same arrangement used for low-slope roof waterproofing coatings in the Metacrylics range.