Sikalastic®-624 WP

Meets ASTM C836 Standard Specification for High Solids Content, Cold Liquid-Applied Elastomeric Waterproofing Membrane for Use with Separate Wearing Course.

Single component, moisture-triggered, aliphatic polyurethane

9 months in original, unopened and undamaged sealed containers.

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.

78.9 %

70.9 %

209 g/L

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)

-30 to 80 °C (-22 to 176 °F) intermittent

5 °C (41 °F) min. / 35 °C (95 °F) max.

80 % R.H. max.

Beware of condensation.
The substrate and uncured coating must be ≥ 3 °C (5 °F) above dew point.

5 °C (41 °F) min. / 60°C (140°F) max.

≤ 4 % moisture content Test method: Sika®-Tramex meter
No rising moisture according to ASTM (Polyethylene-sheet)

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.)

 *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.

Note: Times are approximate and will be affected by changing ambient conditions particularly temperature and relative humidity.

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

No mixing necessary

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.

(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 all tools and application equipment with appropriate solvent immediately after use. Hardened and/or cured material can only be removed mechanically.