Sikalastic®-641 Lo-VOC

Environmental Product Declaration (EPD) - Cradle-to-Grave

• FM Approval Standard 4470 for Class 1 Roof Covers
• UL 790 Class A
• Miami-Dade
• ASTM D 6083
• Florida Building Code

Single component, moisture triggered aliphatic Polyurethane

15 months

Store dry between 35 °F and 77 °F (2–25 °C). Condition material to 50–77 °F (10–25 °C) before using for ease of application

11.9 lb./gal. (1.4 kg/cm³)

-22–176 °F (-30–80 °C) intermittent

Strong resistance to a wide range of reagents, including paraffin, gasoline, 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 recommendations.

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

85 % R.H. max.

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

41 °F (5 °C) min. / 140°F (60°C) max.

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

Sikalastic®-641 Lo-VOC 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 1–2 hours approx. ( at 75 °F (24 °C) and 50 % R.H.)

 *After 7 days the surface must be cleaned and primed with Sika® Concrete Primer Lo-VOC or 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 provided are optimal and are not guaranteed - coverage rates will vary depending on temperature, surface roughness and porosity, aggregate selection and embedment, and application technique. (Refer to Sikalastic® 641 Lo-VOC System Data Sheet)

All substrate surfaces shall be clean, dry and sound. Acceptable substrates include: sound concrete and cementitious screed, metals, wood, modified bitumen, mineralized felt, EPDM, hypalon, TPO, sprayed polyurethane foam, brick and stone, slate and tile, and existing liquid applied membranes. Reference separate System Data Sheet for specific surface preparation requirements.

Primer
Apply primer of a type suitable for the substrate. Allow primer to cure completely before applying Sikalastic®-641 Lo-VOC resin. Reference separate System Data Sheet for specific primer recommendations.

No mixing necessary

Sika Reemat - Base Resin
Apply Sikalastic®-641 Lo-VOC resin to the primed substrate surface by means of 1/2” (12.7 mm) nap phenolic resin core roller or brush at the specified application rate to achieve a uniform and consistent wet mil thickness (reference separate System Data Sheet). Material can also be squeegee or spray applied, in which case it should also be backrolled. Apply Sika Reemat into the wet embedment resin and roll the scrim to achieve full saturation and embedment. Reemat shall be torn/cut to conform to substrate transitions and flashing conditions, with a typical 2” (50.8 mm) reinforcement overlap. Resin shall saturate the Reemat from below. Apply additional Sikalastic®-641 Lo-VOC resin as required to ensure full scrim embedment. Allow to cure completely before applying subsequent resin layers.

Sika Reemat - Intermediate and Top Resin
Apply Sikalastic®-641 Lo-VOC resin to the cured Sikalastic®/Reemat base layer by means of 1/2” (12.7 mm) nap phenolic resin core roller or brush at the specified application rate to achieve a uniform and consistent wet mil thickness (reference separate System Data Sheet). Material can also be squeegee or spray applied, in which case it should also be backrolled. Allow to cure completely before applying any subsequent resin layer, if specified.

Sika Fleece
Apply Sikalastic®-641 Lo-VOC resin to the primed substrate surface by means of 1/2” (12.7 mm) nap phenolic resin core roller or brush to achieve a uniform and consistent thickness, applying approximately 2/3 of the resin required to achieve the specified application rate (reference separate System Data Sheet). Apply Sika Fleece into the wet embedment resin and roll the fleece to achieve partial saturation and full embedment. Fleece shall be cut to conform to substrate transitions and flashing conditions, with typical 3” (76.2 mm) side and 6” (152.4 mm) end reinforcement overlaps. Resin shall saturate the Fleece from below. Apply remaining 1/3 of the specified resin quantity to to ensure full fleece saturation and an even resin application.

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