Sikalastic-835 I – 701 SF Fluid-Applied Protected or Exposed Membrane Roofing-Waterproofing

Sikalastic-835 I with Sikalastic-701 SF is a protected or exposed fluid-applied roofing and waterproofing membrane system from Sika Corporation, written as CSI section 07 55 56. It is a hot-fluid-applied polyurea system for structural concrete, plywood sheathing, metal and other approved substrates. A primer on the substrate is followed by the spray-applied polyurea membrane, and a UV-stable polyaspartic coat finishes exposed roofs. The system can be used in inverted or exposed conditions, and it can receive an overburden of insulation and ballast or concrete pavers.

Areas of use are complicated shaped roofs, exposed roofs, and plaza and podium deck waterproofing. The membrane is also used for roofs suitable for vehicle access and car park decks with concrete overburden.

The assembly is 80 mils dry film thickness (2.0 mm) and uses materials from one manufacturer.

• Primer: Sikalastic EP Primer/Sealer, Sika Concrete Primer Lo-VOC or Sikalastic GDC Primer.
• Sikalastic-835 I: the spray-applied polyurea waterproofing membrane.
• Sikalastic-701 SF: the liquid polyaspartic top coat that gives UV resistance on exposed roofs.

Sika Concrete Primer Lo-VOC is a single-component, rapid curing, high solids, moisture-cured primer. Sikalastic EP Primer/Sealer is a two-component, cyclo-aliphatic, amine-cured material with a high level of corrosion resistance for metal. It also blocks bleed on stable asphaltic surfaces and chemically treated wood. Sikalastic GDC Primer is a two-component, moisture mitigating epoxy primer for green, damp and dry concrete. Sikadur-Combiflex SG, a modified flexible polyolefin membrane set into a solvent-free epoxy adhesive, is the expansion joint over-banding. It comes in 1 mm and 2 mm thicknesses, in 4, 8 and 12 in. widths, and in 20 ft. and 82 ft. rolls.

• Minimum total thickness: 80 mils (1.9 mm).
• Consumption, exposed roofs: Sikalastic-835 I about 20 ft2 per gal (1.8 kg/m2); Sikalastic-701 SF about 160 to 130 ft2 per gal (0.3 kg/m2).
• Consumption, non-exposed roofs: Sikalastic-835 I about 20 ft2 per gal (2.0 kg/m2).
• Working life: up to 20 years, in moderate and severe climatic zones.
• Roof slope: low to high.
• Surface temperature range: -22°F (-30°C) lowest and +194°F (+90°C) highest.
• Reaction to fire: Euroclass E. Watertightness: passed.
• Resistance to wind uplift: 7.25 psi (50 kPa) or more for tear-resistant substrates.
• Resistance to mechanical damage by perforation: on compressible and non-compressible substrates.

The installed system withstands the design pressures calculated under the most current revision of ASCE 7. The listed reference standards include ASTM G53, DIN EN 1062-7, DIN EN 13501, EN 1504-2:2004 and DIN 53109 (Taber abrasion).

Sikalastic-835 I is a liquid hot spray-applied, two-component, elastic, 100% solids, very fast curing pure polyurea membrane. Its chemical base is a two-part aromatic polyurea. It can be installed only with special two-part hot spray equipment: proportioner and spray pump with integral heaters, heated hoses, spray gun, transfer pumps, agitator and gel filters.

• Shore D hardness: about 48 (EN ISO 868).
• Setting or gel time: 5 to 10 seconds. Solid content above 99%.
• Mixed density: about 67.42 lb/ft3 (1.08 kg/l).
• Tensile strength: about 18 N/mm2 in the specification table and about 12 MPa in the data sheet.
• Elongation at break: 250 to 300% in the data sheet, about 350% at 28 days in the specification table.
• Tear strength: about 90 kN/m (UNI EN 12310-2).
• Abrasion: about 20 mg (EN ISO 5470-1, Taber).
• Crack bridging: static Class A4, over 1250 microns at 23°C; dynamic Class B3.1 at -20°C (DIN EN 1062-7).
• VOC content: 0 g/L.
• Resistance to hot poured asphalt applied at up to +464°F (+240°C).
• Resistance to long-term contact with diesel and gasoline for at least 72 hours (ASTM D1308).
• Gas permeability: no leak for helium or methane at 1.2 bar over 40 days; radon 9 Bq/m3.

Standard colors are black (RAL 9005), medium gray (RAL 7040) and white (RAL 9010), with other colors on request. Resin comes in 55 gal. drums of about 205 kg and isocyanate in 55 gal. drums of about 225 kg, which together make a 109 gal. kit. Both components have a 12 month shelf life from production when stored sealed on pallets at 41 to 86°F (5 to 30°C).

Approvals and standards named for the membrane are CE marking to EN 1504-2, reaction to fire class E (EN 13823), accelerated weathering (ASTM G53), the B.C.R.A. slip coefficient method and ASTM C836-18. The membrane carries a LEED rating of EQ credit 4.2, Low Emitting Materials: Paints and Coatings.

Sikalastic-701 SF is a two-component, 100% solids, low odor polyaspartic top coat with a polyaspartic resin base. It is cold applied by roller or squeegee in a single coat at about 10 to 12 mils wet, which covers 160 to 133 ft2 per gallon. It is white, self-smoothing and high gloss.

• Mixing ratio: Part A to Part B by weight 2.1 to 1. Pot life is 30 minutes at 68°F.
• Shore D hardness: 53. Tensile strength: 2,378 psi. Elongation: 103%. Tear strength: 534 psi.
• Water vapor transmission: 0.28 perms (ASTM E96 Method B).
• Solar reflectance 0.86 initial and 0.73 rapid; thermal emittance 0.91 and 0.90; both for white (CRRC). External fire performance B roof (T1) and B roof (T4).
• VOC content: 1.41 g/L. Abrasion resistance class AR 0.5 special.
• At 68°F and 50% R.H.: tack free in 90 minutes, rain resistant in 60 minutes, foot traffic in 180 minutes, full cure in 1 day.

Where slip resistance or a walkway is needed, oven-dried 16/30 or 20/40 silica sand is broadcast to refusal into the wet second top coat. Opening to traffic before cure can cause loss of aggregate or permanent staining.

Concrete is sound, with a compressive strength of at least 25 MPa (3500 psi) and a pull-off strength of at least 1.5 N/mm2, and new concrete is at least 7 days old in the specification and 28 days in the data sheet. Surfaces are prepared mechanically to ICRI CSP profiles to remove laitance and curing compounds. If concrete moisture content is above 4%, Sikalastic GDC Primer is used. Absorbent substrates are primed with EP Primer/Sealer and lightly broadcast with 0.4 to 0.7 mm quartz sand before the membrane.

Substrates that are always primed are cementitious surfaces, bricks, tiles and metal. Metal is blast cleaned to Sa 2 1/2 (ISO 8501-1) or SSPC-SP 10 or 11, primed with EP Primer/Sealer, and Sika Joint Tape SA is applied along joints, cracks and fastener locations. Bituminous membranes are clean, intact and fully adhered, and cracks are repaired with like materials before pressure washing. Volatile bituminous materials can stain the coating unless the right primer is used.

Sikalastic-835 I is not applied directly on TPO or plasticized PVC. Application is possible from 5°F (-15°C) to +158°F (+70°C), and the cured membrane performs in constant dry temperatures from -22°F (-30°C) to +284°F (+140°C). Odors and vapors are kept out of the building by sealing air intakes during application and cure. The system matches the reinforced liquid-applied membranes used on podium decks, plazas and complicated roof shapes.