Sikalastic®-624 WP
Sikalastic®-624 WP waterproofing systems combine a cold-applied, aliphatic, one-component, alkali-resistant, moisture-triggered polyurethane resin with glass fibre mat or polyester fleece reinforcement to create a seamless membrane and flashing system. Typical applications include a separate wearing course (overlayment or overburden), but Sikalastic®-624 WP is UV-resistant without protection board and is therefore suitable for direct exposure waterproofing applications as well. System components are:
- Sika® or Sikalastic® Primer - Select primer per substrate material in accordance with Priming Guide.
- Sikalastic®-624 WP - Resin used for all systems with both Reemat™ fiberglass and polyester fleece reinforcement.
- Sikalastic® Reemat™ Premium - Chopped strand glass fibre mat.
- Sika® Fleece 120, 140, 170 - Non-woven, needle-punched polyester fleece in various weights.
- Proven technology with over 25 year track record.
- Single component - no mixing and ready to use.
- Fully reinforced with highly conformable Sika® Reemat™ or Sika® Fleece.
- Integrated flashings utilizing same resin and reinforcements.
- Ideal for complex details and geometry or when accessibility is limited.
- Moisture-triggered chemistry that is rapidly weatherproof after application.
- Highly elastic and crack bridging.
- Seamless and fully-adhered.
- Vapor permeable.
- UV-resistant and non-yellowing.
- Abrasion and chemical resistant.
- Alkali-resistant formulation.
Usage
- Sikalastic® waterproofing systems, including Sikalastic® Plaza Deck/PMA and Vegetated systems for both new construction and refurbishment.
- Split-slab waterproofing.
- Vegetated deck waterproofing.
- Plaza decks with concrete pavers, and asphalt or concrete paving stones in a sand bed.
- Waterproofing under tile in a mortar bed.
- Applications involving cementitious and asphalt pavement overlays.
- Waterproofing around/beneath mechanical equipment.
Advantages
- Proven technology with over 25 year track record.
- Single component - no mixing and ready to use.
- Fully reinforced with highly conformable Sika® Reemat™ or Sika® Fleece.
- Integrated flashings utilizing same resin and reinforcements.
- Ideal for complex details and geometry or when accessibility is limited.
- Moisture-triggered chemistry that is rapidly weatherproof after application.
- Highly elastic and crack bridging.
- Seamless and fully-adhered.
- Vapor permeable.
- UV-resistant and non-yellowing.
- Abrasion and chemical resistant.
- Alkali-resistant formulation.
Packaging
18.9 L (5 US gal.) pail
Colour
White (RAL 9016), Pearl Gray
Product Details
APPROVALS / CERTIFICATES
Meets ASTM C836 Standard Specification for High Solids Content, Cold Liquid-Applied Elastomeric Waterproofing Membrane for Use with Separate Wearing Course.
Composition / Manufacturing
Single component, moisture-triggered, aliphatic polyurethane
Shelf Life
9 months in original, unopened and undamaged sealed containers.
Storage Conditions
Store dry at temperatures between 2 - 25 °C (35 - 77 °F). Condition material at temperatures between 10 - 25 °C (50 - 77 °F) before using and for ease of application.
Density
| 1.3 kg/L (10.8 lb/US gal.) | (all values at +23 °C) |
Solid content by weight
78.9 %
Solid content by volume
70.9 %
Volatile organic compound (VOC) content
209 g/L
Tensile Strength
| Ref. reinforced system data | (ASTM D-751) |
Resistance to Static Puncture
| Ref. reinforced system data | (ASTM D-5602) |
Chemical Resistance
Strong resistance to a wide range of reagents, including paraffin, petrol, fuel oil, white spirit, acid rain, detergents and moderate solutions of acids and alkalis. Some low molecular weight alcohols can soften the material. Contact Technical Service for specific recomendations. Salt spray to ASTM B117 (1000 hours continuous exposure) and prohesion testing to ASTM G85-94: Annex A5 (1000 hours cyclic exposure)
Service Temperature
-30 to 80 °C (-22 to 176 °F) intermittent
Application
Ambient Air Temperature
5 °C (41 °F) min. / 35 °C (95 °F) max.
Relative Air Humidity
80 % R.H. max.
Dew Point
Beware of condensation.
The substrate and uncured coating must be ≥ 3 °C (5 °F) above dew point.
Substrate Temperature
5 °C (41 °F) min. / 60°C (140°F) max.
Substrate Moisture Content
≤ 4 % moisture content Test method: Sika®-Tramex meter
No rising moisture according to ASTM (Polyethylene-sheet)
Pot Life
Sikalastic®-624 WP is designed for fast curing. High temperatures combined with high air humidity will increase the curing process. Thus, material inopened containers should be applied immediately. In opened containers, the material will form a film after 1 hour approx. ( at 24 °C (75 °F) and 50 % R.H.)
Curing Time
| Ambient conditions | Minimum waiting time overcoating |
| +4 °C (+40 °F) / 50 % r.h. | 14 hours |
| +10 °C (+50 °F) / 50 % r.h. | 6 hours |
| +21 °C (+70 °F) / 50 % r.h. | 5 hours |
*After 7 days the surface must be cleaned and primed with Sika® Reactivation Primer before continuing.
Note: Times are approximate and will be affected by changing ambient conditions particularly temperature and relative humidity.
Applied Product Ready for Use
| Ambient conditions | Rain resistant | Touch dry | Full cure |
| +4 °C (+40 °F) / 50 % r.h. | 10 min. | 12 hours | 24 hours |
| +10 °C (+50 °F) / 50 % r.h.. | 10 min. | 6 hours | 18–24 hours |
| +21 °C (+70 °F) / 50 % r.h. | 10 min. | 4 hours | 12–18 hours |
Note: Times are approximate and will be affected by changing ambient conditions particularly temperature and relative humidity.
Consumption
| Sika Reemat | Sika Fleece |
| 1.3 m2/L (53 sf/gal) - 0.76 mm (30 mils) w.f.t.* | 0.37 m2/L (15 sf/gal) - 2.67 mm (105 mils) w.f.t.* |
| 0.98 m2/L (40 sf/gal) - 1.02 mm (40 mils) w.f.t.* | 0.47 m2/L (19 sf/gal) - 0.48 mm (85 mils) w.f.t.* |
| 0.86 m2/L (35 sf/gal) - 0.89 mm (45 mils) w.f.t.* | 0.56 m2/L (23 sf/gal) - 1.78 mm (70 mils) w.f.t.* |
NOTE: Coverage rates are optimal - coverage rates will vary depending on temperature, surface roughness and porosity, and application technique.
*w.f.t.: wet film thickness
MIXING
No mixing necessary
APPLICATION
Substrate Evaluation
Concrete and cementitious substrates
New concrete shall be allowed to cure a minimum of 28 days. Concrete shall have a minimum compresive strength of 20.7 MPa (3000 psi) and exhibit a minimum tensile bond strength of 1.4 MPa (200 psi).
Moist or sheet curing methods should be used, as opposed to the use of curing compounds, which may interfere with the bond of the membrane. Inspect the concrete, including upstands, and all areas should be hammer tested. Concrete must be suitably finished, preferably by wood float or steel pan.
A power float finish is acceptable where the surface is prepared to avoid laitance (a tamped finish is not acceptable). The surface finish must be uniform and free from defects such as laitance, voids or honeycombing.
Gypsum and Cement based sheathing
Sheathing boards shall be clean, dry and dust-free, and shall be properly secured to the structure. Loose, damaged, or contaminated boards shall be removed and replaced.
Brick and stone
Mortar joints must be sound and preferably flush pointed.
Asphalt
Asphalt contains volatiles which can cause bleeding and slight non-detrimental staining. The asphalt must be carefully assessed for moisture and/or air entrapment, grade and surface finish.
Bituminous felt
Ensure that bituminous felt is firmly adhered or mechanically-fixed to the substrate. Bituminous felt shall not contain badly degraded areas.
Bituminous coatings
Bituminous coatings shall not have sticky or mobile surfaces, volatile mastic coatings, or old coal tar coatings.
Metals
Metals must be in sound condition.
Wooden substrates
Plywood and timber-based decks must be in good condition, firmly adhered and mechanically-fixed. All plywood should be identified as conforming to PS 1 for construction and industrial plywood by grade, APA (American Plywood Association) trademark, or equivalent. For maximum smoothness, EXT Type APA, Grade A-C should be used, and the “A” sides should be positioned to receive the Sikalastic® resin. Plywood decks to receive resin directly shall be at least 12.7 mm (1/2 in) thick and attached and supported according to APA guidelines, using only non-rusting screw, spiral or coated nail type fasteners. A good practice would be to recess or counter sink fasteners 3.2 to 6.4 mm (1/8 to 1/4 in) and fill with an appropriate Sikaflex® sealant. Suitable edge support to prevent differential deflection between panels shall be provided. Panel edges shall be tongue and groove or supported on solid blocking. Space panels 3.2 to 4.8 mm (1/8 to 3/16 in) at panel ends.
Paints and coatings
Ensure the existing material is sound and firmly adhered.
Existing Sikalastic system
The existing Sikalastic® system shall be soundly adhered to the substrate.
Surface Preparation
Concrete and cementitious substrates
Cementitious or mineral based substrates must be prepared mechanically using abrasive blast cleaning or scarifying equipment to remove cement laitance and to achieve an open textured surface (ICRI/CSP 3 - 5). Loose friable material and weak concrete must be completely removed and surface defects such as blowholes and voids must be fully exposed. The amount of embedment coat required may increase over rough or highly porous surfaces.
Gypsum and Cement based sheathing
Sheathing boards shall be clean, dry and dust-free. Secure loose boards if in sound condition. Damaged or contaminated boards shall be removed and replaced.
Brick and stone
Power wash and use biodegradeable non-sudsing detergent with clean water rinse as required.
Asphalt
Power wash and use biodegradeable non-sudsing detergent with clean water rinse as required. All major cracks should be sealed to allow continuity of the Sikalastic® system.
Bituminous felt
Power wash and use biodegradeable non-sudsing detergent with clean water rinse as required. Treat blisters by star cutting and removing any underlying water. Allow to dry and re-adhere using suitable adhesive.
Bituminous coatings
Remove any loose or degraded coatings.
Metals
Ferrous metals should be thoroughly cleaned by grinding or blast cleaning prior to priming (SSPC-SP3 to nearwhite metal.)
Non-ferrous metals are prepared by removing any deposits of dust and oxidation and abrading to bright metal. Wire brushing can be used for soft metal such as lead. The surface must be clean and free from grease which, if present, must be removed with a solvent wipe or wash with detergent, rinse and dry.
Wooden substrates
Timber and timber based decks require additional reinforcement such as the installation of plywood, approved insulation or cover board. Small timber protrusions and suitable decks may be treated directly, provided that the timber is of exterior quality, e.g., exterior grade plywood, etc. Fill joints flush with an appropriate Sikaflex® sealant.
Paints/Coatings
Remove any loose or degraded coatings. Ensure the surface is clean and free from grease.
Sikaplan®/Sarnafil® membranes
Clean membranes with Sarna Cleaner (PVC membranes) and Sarnafil® T Clean (FPO membranes) prior to application of primer.
Existing Sikalastic Systems
Clean the membrane using a water jet at approximately 140 bar (2000 psi) and biodegradeable non-sudsing detergent with clean water rinse. Allow to dry.
Application
Refer to Priming Guide to select primer for properly evaluated and prepared substrate. Refer to separate primer Product Data Sheet for for application methods, coverage rates, cure times and recoat windows. Always allow primer to cure thoroughly before applying detail or base resin layer.
| Substrate | Remark | Concrete Primer | DTE Epoxy Primer | Bonding Primer |
| CONCRETE | (1) | X | X | X |
| LIGHTWEIGHT CONCRETE | (1) | X | ||
| BRICK, STONE | (3) | X | ||
| BITUMINOUS SUBSTRATE | ||||
| - Asphalt, bitumininous felts, bituminous coatings, granulated or smooth SBS & APP cap sheets | (2,3) | |||
| ROOF TILES (UNGLAZED) | (3,4) | X | ||
| METALS | ||||
| - Aluminum, galvanized, cast iron, copper, lead, brass, stainless steel, steel, zinc | (3) | |||
| PRE-COATED METAL | (3) | |||
| PAINTS | (3) | |||
| - Paints & coatings | (3) | |||
| - Aluminized solar reflective coatings | (3) | |||
| WOOD- TIMBER & PLYWOOD | (3) | X |
| Substrate | Remark | EP Primer/Sealer | Contact Sika |
| CONCRETE | (1) | X | |
| LIGHTWEIGHT CONCRETE | (1) | X | |
| BRICK, STONE | (3) | X | |
| BITUMINOUS SUBSTRATE | |||
| - Asphalt, bitumininous felts, bituminous coatings, granulated or smooth SBS & APP cap sheets | (2,3) | X | |
| ROOF TILES (UNGLAZED) | (3,4) | X | |
| METALS | |||
| - Aluminum, galvanized, cast iron, copper, lead, brass, stainless steel, steel, zinc | (3) | X | |
| PRE-COATED METAL | (3) | X | |
| PAINTS | (3) | ||
| - Paints & coatings | (3) | X | |
| - Aluminized solar reflective coatings | (3) | X | |
| WOOD- TIMBER & PLYWOOD | (3) | X | X |
(1) New cementitious substrates must be Portland base and be cured min. 28 days.
(2) The presence of volatiles may cause discoloration of Sikalastic if not properly primed.
(3) Surface evaluation and filed adhesion testing
(4) Glazed tile consult Sika
(5) Pressure treated lumber consult Sika
TOOLING AND FINISHING
See above.
REMOVAL
Remove liquid resin immediately with dry cloth. Once cured, resin can be removed by mechanical means.
OVER PAINTING
See above.
CLEAN UP
Clean all tools and application equipment with appropriate solvent immediately after use. Hardened and/or cured material can only be removed mechanically.