Sikalastic 702 – 701 SF Fluid-Applied Protected or Exposed Membrane Roofing-Waterproofing

Sikalastic-702 is a two-component, cold applied, self-smoothing, elastic polyurea hybrid liquid membrane from Sika Corporation, with an elastomeric PU/PUA hybrid chemical base. Paired with the Sikalastic-701 SF top coat it forms the protected or exposed membrane roofing and waterproofing system in CSI section 07 55 56. The system is a cold-fluid-applied polyurea hybrid system for structural concrete, plywood sheathing, metal and other approved substrates.

Sikalastic-702 is designed for flat or protected roofing and waterproofing in new construction and refurbishment. It suits roofs with many details such as penetrations, drains, roof lights and complex geometry. It also serves balcony and terrace decks under a protective layer such as ballast, paving slabs or tiles, and small projects where spray machinery is not practical. It needs no heat or flame and is hand applied by notched rubber or metal squeegee. Only experienced professionals use it.

• Packaging: Part A 1 gal, Part B 4 gal, kit 5 gal.
• Color: medium gray.
• Shelf life: 12 months for both components, stored at 41 to 86°F (5 to 30°C).
• Mixing ratio: Part A to Part B 1 to 1.72 by weight. Mixed density 1.180 g/L (ASTM D1475).
• Solids: about 100% by mass and volume. VOC content: 2.94 g/L.
• Tensile strength: about 10.0 N/mm2 (DIN EN ISO 527-3). Elongation at break: about 900%.
• Tensile adhesion strength: about 2.5 N/mm2 (DIN EN ISO 4624), measured with Sika Concrete Primer LO.
• Tear strength: about 13.8 N/mm2 (ISO 6383-2).
• Crack bridging ability: pass (ASTM C1305). Retention of properties after heat aging: pass (ASTM C1522).
• Water vapor transmission: 0.10 perms (ASTM E96 Method B).
• External fire performance: B roof T1 and B roof T4. Combustibility: Euroclass E (EN 13501-1).
• Resistance to root penetration: root resistant (DIN CEN/TS 14416).

Approvals and standards for Sikalastic-702 are as follows.

• Root resistance to DIN CEN/TS 14416, kiwa test report 0078.0.1-2019e.
• CE marking and Declaration of Performance to ETAG 005-1-6:2004, liquid-applied roof waterproofing using kits based on polyurethane.
• Fire testing to EN 13501-5 (Warringtonfire reports 19895B and 19895C) and EN 13501-1 (report 19896B), on Sikalastic-701.
• ASTM C836-18.
• ANSI A118.10, load-bearing thin-set ceramic tile and stone, and ANSI A118.12, crack isolation for thin-set ceramic tile and stone.

In the guide specification the membrane is not intended to sit in contact with a constant temperature below -22°F (-30°C) or above 196°F (90°C). It resists gasoline, paraffin, fuel oil, mineral spirits, moderate solutions of acids and alkalis, acid rain and detergents.

The membrane is built in several defined layer stacks, each over a primer matched to the substrate.

• Exposed system for chemical containment or cooling tower areas: Sikalastic-702 base layer at 80 wet mils (about 20 sf per gal), then a Sikalastic-701 SF top layer at 10 to 12 wet mils (about 160 to 130 sf per gal). Warranty length 20 years.
• Exposed unreinforced system: the same 80 wet mil base and 701 SF top layer. Minimum dry film thickness is 88 mils for the 702/701 SF build and 80 mils for the 702-only build.
• Unreinforced protected membrane: two layers of Sikalastic-702 at 40 wet mils each (about 40 sf per gal).
• Reinforced system, local or full: 702 base layer at 40 wet mils, PAREX Synergy Reinforcing Mesh 355, a second 702 layer at 40 wet mils, and an optional 701 SF UV protection layer at 10 to 12 wet mils.

System warranty lengths are 10 and 20 years under a manufacturer's standard limited labor and materials warranty, with a materials warranty of at least one year from Substantial Completion. The performance table in the guide specification has an overall thickness of about 2.3 mm (90 mils dry), a 702 base coat at 80 wet mils at 80 ft2 per gallon, and a 701 SF top coat at 8 to 10 wet mils.

PAREX Synergy Reinforcing Mesh 355 is a 4.5 oz fiberglass mesh in rolls 38 in. wide by 150 ft long, alkali resistant, for full or local reinforcement of Sikalastic-702 or 702 THX. Sika Joint Tape SA is applied to primed surfaces at structural cracks, expansion joints and transitions of dissimilar materials, or the mesh is set in the wet base coat, centered over laps, seams, cracks and joints.

Sikalastic-702 THX is the two-component, thixotropic, hand-applied version for detail work. It is required on all sloped and vertical surfaces. Sikalastic-702 and 702 THX are overcoated with 701 SF within 48 hours. Exposed finish sealant is Sikaflex Hyflex 150 LM, a one-part low-modulus hybrid sealant, or Sikasil WS-295, a one-part silicone sealant for terminations at saw cuts and UV-exposed sealant ends. Sika Reactivation Primer, a single-component polyurethane primer, restores the surface when the open window between coats is exceeded.

Pot life is about 25 minutes at 68°F (20°C) and shortens as temperature rises. Product temperature is 50 to 77°F (10 to 25°C). Ambient air and substrate are 35.6 to 104°F (2 to 40°C), with relative humidity 35 to 80% and the surface at least 5°F above the dew point. Substrate moisture is 4% or less.

• At 50°F and 50% R.H.: rain resistant in about 3 hours, foot traffic or overcoating in about 10 hours, full cure in about 28 hours.
• At 68°F and 50% R.H.: about 2 hours, about 6 hours and about 24 hours.
• At 86°F and 50% R.H.: about 1 hour, about 4 hours and about 20 hours.

Sikalastic-701 SF is a white, two-component, 100% solids, low odor polyaspartic coat with a polyaspartic resin base, used here as the UV resistant layer over 702. It is rolled or squeegeed at 10 to 12 mils wet in one coat and carries a CRRC listing. Its mix ratio is 2.1 to 1 by weight, with Part A in a 0.7 gal container and Part B in a 0.49 gal container. Initial solar reflectance is 0.86 and thermal emittance is 0.91. Final drying takes 180 minutes at 68°F. Where a walkway or slip resistance is needed, 16/30 or 20/40 oven-dried silica sand is broadcast to refusal into the wet second top coat. For a cementitious overlay, 30/60 silica sand is broadcast into an added coat of 702 as an adhesion key.

Approved substrates are concrete slabs, concrete, cementitious surfaces and metals. Asphaltic built-up roofs, bituminous felts and coatings, brickwork and asbestos cement are also suitable substrates. Primers are Sika Concrete Primer Lo-VOC, Sikalastic Primer EP or EP Rapid for concrete, Sikalastic GDC Primer for green and damp concrete and plywood, and Sikalastic EP Primer/Sealer or EP Primer Rapid for metal.

New concrete cures at least 28 days with a compressive strength of 3000 psi (20.7 MPa) and a tensile bond strength of 200 psi (1.4 MPa). Moist or sheet curing is used rather than curing compounds. Surfaces are prepared to ICRI CSP 2 to 4, and ferrous metals are ground or blast cleaned (SSPC-SP3 to SP11). A protection layer separates the membrane from overburden. Exposed to direct sunlight the 702 layer discolors, so the UV layer goes on within 7 days. The system is not placed on grade concrete decks or over ceramic tile. It matches the liquid-applied roofing membranes used on terraces and complex roofs.