SikaScreed®-40 Bond Coat

6 months from date of production when stored in original, sealed package

Store in undamaged, unopened, original sealed packaging in dry conditions at temperatures between 5 °C (41 °F) and 35 °C (95 °F). Protect from direct sunlight, heat and moisture.

Between 30 and 45 minutes

10 to 15 minutes

JOB SITE CONDITIONS

Maintain environmental conditions and protect work during and after installation. Comply with trade and industry standards and manufacturer's printed recommendations.

For interior jobs in cold conditions, turn off all forced ventilation and radiant heating systems and protect the work against drafts during installation and for at least 72 hours after completion. When necessary, use indirect auxiliary heaters to maintain an adequate temperature level in the working area (ambient and surface temperatures). Exhaust temporary heaters to the exterior to prevent damage to the work or personal injury from carbon monoxide emissions. Maintain work area at a temperature no lower than 13 °C (55 °F) for at least 24 hours before and after the installation.

For interior jobs in hot conditions (with temperatures exceeding 35 °C (95 °F), which can be defined as any combination of high air temperature, low relative humidity and wind velocity that can affect the performance of surface preparation consider adjusting the time of the application to a cooler or at least shaded time of the day. Protect from adverse weather conditions (such as but not limited to rain) for at least 24 hours.

For exterior applications, to achieve performance consistent with Technical Data, curing is required and must be provided as per ACI 308 recommendations for cement concrete. Use recognized curing methods, such as a white polyethylene film over the SikaScreed®-40 mortar. Curing must begin immediately after placing and finishing and remain in place for at least 24 hours.

SUBSTRATE QUALITY (regarding concrete substrates)

Surface treatments or any friable areas of the substrate must be mechanically eliminated. Aggressive mechanical preparation (such as but not limited to using a scarifier or a chipping hammer may invite micro bruising of the substrate) Contact Sika’s Technical Services for additional information.

Expansion joints should comply with detail 301MJ Movement joint guidelines per TTMAC.

Warning: Refer to the Regulations Made Under the Canada Labour Code for additional information regarding requirements for handling surface containing or suspected of containing lead-based paints or any flooring, substrate or substances that may contain asbestos.

All supporting surfaces should be structurally sound, solid, stable. Surfaces should be clean and free of dust, oil, grease, paint, tar, wax, curing agent, primer, sealer, form release agent and any deleterious substance or conditions that may prevent, reduce or inhibit adhesion or performance. Before work commences, examine the areas to be covered and report any improper condition(s) in writing to the general contractor, architect or engineer. User shall not proceed with the work until surfaces and conditions comply with the requirements indicated in this document; applicable industry standards; federal, provincial and local regulations, as well as good trade practices. By starting work, the Applicator/User acknowledges that the conditions are acceptable.

Concrete (and cementitious substrates)

Concrete must be cured for a minimum of 28 days. Surface should have a minimum surface profile of CSP 2 (ICRI - International Concrete Repair Institute). Alternatively, mechanical preparation should consist of an abrasive screen with a floor polisher (or light diamond cup grinding) towards scuffing up the surface. On grade or below grade concrete slabs must be installed over an effective vapour barrier. On a clean and dust-free substrate, place a single drop of portable water (quarter size) on the substrate using a pipette. The concrete should turn dark. If the drop is absorbed within 60 seconds, the substrate can be considered porous (or absorptive) and acceptable for using SikaScreed®-40 Bond Coat. Otherwise, a bond test should be performed to confirm an adequate bond. If an adequate bond cannot be achieved, the concrete surface should be abraded, and additional bond tests should be conducted. If an adequate bond cannot be achieved or in doubt, contact Sika’s Technical Services.

Note: Concrete surfaces finished with a wood float, magnesium float or with a steel trowel with a broom will positively impact bond perforrmances

In a clean container, add approximately 4.70 L (1.24 US gal.) of clean potable water. Then add 1⁄2 bag of SikaScreed®-40 Bond Coat and mix at slow speed until a wet slurry is obtained. Add 1⁄4 bag and mix between 200-300 rpm until powder comes to a loose paste consistency. Add final 1⁄4 bag and mix thoroughly to a smooth and homogeneous consistency. Mortar consistency shall be such that when applied with the recommended notched trowel to the substrate, the ridges formed in the mortar do not flow or slump.

NOTE: No Slake Technology - No wait, just mix and trowel 

On rough concrete

Apply 3 to 4 mm (120 mils to 160 mils) of SikaScreed®-40 Bond Coat and using a stiff nylon brush, scrub it onto the concrete surface.

Over concrete (and cementitious substrates) that has a scuffed up surface

With pressure, apply a coat of SikaScreed®-40 Bond Coat by using the smooth edge of a 6 mm x 6 mm x 6 mm (1/4 in x 1/4 in x 1/4 in) squared notched trowel in order to key the mortar into the substrate. With the notched side of the trowel, apply additional mortar by combing it in a single direction.  Follow promptly use the smooth edge of the trowel by applying a small amount of pressure in order to flatten the bonding agent ridges and achieve a continuous film of 3 to 4 mm (3/32 to 1/8 in). 

Note: If the scrubcoat dries or skins over before SikaScreed®-40 mixture can be applied. Scrape it off the surface of the concrete and discard it. Recoat before applying SikaScreed®-40. 

While the SikaScreed®-40 Bond Coat is still wet, spread a small amount of the SikaScreed®-40 mixture onto the bond coat. Then work the SikaScreed®-40 with a wood or magnesium float into the SikaScreed®-40 Bond Coat. Do not attempt to apply the SikaScreed®-40 at a great thickness of mortar directly to the scrub coat of SikaScreed®-40 Bond Coat as this will affect the bond performance between SikaScreed®-40 Bond Coat and the SikaScreed®-40.

Follow immediately with more SikaScreed®-40 to the desired height (up to 15 cm [6 in]), compacting and closing up the surface. Proceed likewise until the entire floor surfacing is completed. Let the SikaScreed®-40 cure for at least 5 hours based at 23 °C (73 °F) before allowing light traffic and/or before the next planified step.

Clean all tools and equipment after use with water. Once hardened, the product can only be removed manually or mechanically.