DDAA-1P-6xE — New-construction reinforced roof system

DDAA-1P-6xE is a one-ply all-acrylic Western Colloid roof system. It is headed New Construction or Re-Roof, Insulation/DensDeck Prime, Concrete, and the line 1 Ply Polyester Reinforced - Acrylic Surface. It is a cold process, water based membrane for new construction or re-roofing over approved combustible or non-combustible decks. The system can go directly on concrete, over concrete and wood decks using insulation and DensDeck Prime, or over existing membranes. It has very low odor. This DDAA assembly lists Factory Mutual Standard 4470 Class 1, U.L. Class A, LEED (USGBC), Energy Star and California Title 24. Wind uplift is 1-510 (FM) for DensDeck and 1-990 (FM) for concrete.

Four layers form the membrane. Approximate dry weights per 100 sq. ft. do not include the weight of DensDeck.

• 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

Total system dry weight is 44.5 lb and approximate total dry thickness is 65 mils.

The concrete deck is cured, smooth and uniform, with no ridges or voids, and clean of dust and debris. A wood deck needs secured nails, joint gaps of 1/4 inch or less and repair of deteriorated areas. Where insulation is installed, curbs, flashings and vents are raised to meet local or state code requirements. Boards go in following building code, insurance requirements and the board manufacturers' instructions. Insulation uses rigid polyisocyanurate to ASTM C-1289, and DensDeck Prime is a gypsum board with a primed fiberglass mat facer to ASTM C-1177. Attachment is with INSTA STIK adhesive in ribbons or full applications, and layered joints are staggered at least 12 inches.

DensDeck Prime joints, including terminations at penetrations, curbs and walls, are caulked and filled with #800 Elastic Cement or approved caulking. Where a gap reaches 1/4 inch, it is three coursed with #800 and 4 inch polyester fabric. The #800 three course method puts down 1/8 inch per 100 sq. ft. for the first coat, 20 sq. ft. per gallon, and then a thinner second coat for a finished thickness of about 1/8 inch.

A single coat of ElastaHyde at 3 gallons per 100 sq. ft. takes a full-width polyester ply starting at the low edge. The ply ends 2 inches above the cant after light brooming to saturation. Pipe flashings and exposed metal joints are then treated with #800 and fabric. Areas around drains, scuppers, valleys and waterways that pond for more than 48 hours take an extra ply of polyester in ElastaHyde, extending 12 inches past the ponding area. The reflective finish is two coats of 1 1/2 gallons per 100 sq. ft., cross-hatched, with 24 hours of drying after the first. Together these steps make a polyester-reinforced liquid-applied roof.

ElastaHyde 720 ARC has tensile strength above 250 psi and elongation above 250 percent when new and above 175 percent after weathering (ASTM D2370). Solids are 53 percent by volume and 66 percent by weight. It is applied at a minimum of 50 degrees F and a maximum of 100 degrees F ambient. The coating is cleaned from equipment with soap and warm water, and for optimum energy savings it is cleaned yearly.

Application starts at 55 degrees F and rising. Wet weather, rain, snow and freeze rule out application. So do ice or frost on the roof surface or deck, and rain, inclement weather or temperatures below 40 degrees F expected within 48 hours afterward.

• 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

• 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)
• Application temperature: minimum 50 degrees F, maximum 100 degrees F ambient
• Drying time: 1 hour at 100 sq. ft. per gallon, 70 degrees F and 50 percent relative humidity
• Dry film thickness: minimum 20 mils, 24 or more recommended

The white coating is standard, and California Tan (a light tan) and Platinum Gray (a light gray) are also offered, with custom colors available. It is listed by the Cool Roof Rating Council. White, California Tan and Platinum Gray meet California Title 24 and are the colors named for ENERGY STAR. A Quick Set (QS) formulation is made for jobs where damp, wet or rainy weather is expected before the coating fully dries. The coating comes in 5-gallon pails, 55-gallon drums, totes and bulk tankers.

Recommended uses are conventional and modified built-up roofs, existing spray polyurethane foam roofs, and the topcoat of Western Colloid fluid applied reinforced roofing (FARR) and metal roof systems. The coating is not recommended over wood shingles or untreated wood, and it is not recommended on surfaces that pond water for more than 72 hours without reinforcement.

• White (#800W) or black (#800B); the black dries faster in cold weather
• Packaging: 5-gallon pails
• Total solids: 65 to 70 percent by weight
• Elongation: greater than 500 percent; remains flexible below freezing
• Application temperature: minimum 50 degrees F
• Cure through dehydration: 1 to 2 days; tack free in 1 hour; can be coated in 1 to 2 hours
• Maximum single application: less than 3/16 inch thick, with multiple coats where more is required