Sikagard®-381
Sikagard®-381 is a self-levelling, two-component, solvent-free, epoxy Novolac binder and high build, smooth coating available in unlimited colours. Sikagard®-381 is typically installed as an impermeable, seamless surface that provides extremely high chemical and mechanical resistance.
- Excellent protection for new or old concrete and properly prepared steel surfaces.
- Available in unlimited colour range with no minimum quantities required.
- Outstanding chemical resistance.
- High mechanical resistance.
- Excellent abrasion resistance.
- Durable, impermeable and seamless surface.
- High compressive strength within 24 hours.
- Achieves high performance ratings according to ASTM G21 resistance to fungi (rated 1 (traces of growth)) and ASTM D3273 resistance to mold growth (special order grade) (rated 10 (highest resistance)).

Usage
- As a binder for high-performance, self-levelling epoxy mortars.
- As a coating for concrete inbound areas and catch basins for chemically aggressive liquids.
- As a protective coating for concrete in solvent rooms, battery rooms and storage rooms.
- For specific chemical resistance refer to Sika’s chemical resistance chart.
Advantages
- Excellent protection for new or old concrete and properly prepared steel surfaces.
- Available in unlimited colour range with no minimum quantities required.
- Outstanding chemical resistance.
- High mechanical resistance.
- Excellent abrasion resistance.
- Durable, impermeable and seamless surface.
- High compressive strength within 24 hours.
- Achieves high performance ratings according to ASTM G21 resistance to fungi (rated 1 (traces of growth)) and ASTM D3273 resistance to mold growth (special order grade) (rated 10 (highest resistance)).
Packaging
10 L unit (2.64 US gal.) unit
Colour
Refer to the Industrial Flooring and Coatings colour card.
RAL 7046 Telegrey 2. Special colours (on request)
Refer to current price list for availability
Product Details
ENVIRONMENTAL INFORMATION
Potential contribution for LEED® projects.
APPROVALS / CERTIFICATES
Meets the requirements of CFIA and USDA for use in food plants.
Shelf Life
2 years when stored in original, unopened packaging.
Storage Conditions
Store dry at 5 °C to 32 °C (41 °F to 89 °F). Condition product between 18 °C and 30 °C (65 °F and 86 °F) before using.
Density
~1.6 kg/L (~13.34 lb/US gal.)
Volatile organic compound (VOC) content
≤ 65 g/L
Abrasion Resistance
~100 mg (~0.0035 oz) | (ASTM D4060) CS-17/1000 g (2.2 lb)/1000 cycles |
Compressive Strength
~80 MPa (~11 603 psi) | (ASTM D695) |
Tensile Strength in Flexure
~55 MPa (~7977 psi) | (ASTM D790) |
Tensile Strength
~45 MPa (~6527 psi) | (ASTM D638) |
Pull-Off Strength
> 2.7 MPa (> 392 psi) (concrete failure) | (ASTM D7234) |
Coefficient of Friction
~0.20 Wet (smooth coating) | (ANSI A326.3) BOT 3000e |
Temperature Resistance
Continuous exposure | up to 50 °C (122 °F) |
Cleaning with warm water | up to 80 °C (176 °F) |
Short time dry heat exposure | up to 100 °C (212 °F) |
Chemical Resistance
Contact Sika Canada
Application
Mixing Ratio
A:B = 3.48:1 by volume
Product Temperature
Condition product at temperatures between 18 °C and 24 °C (65 °F and 75 °F) before using.
Ambient Air Temperature
Minimum 10 °C (50 °F) Maximum 30 °C (85 °F)
Mixing and application attempted at material, ambient and/or substrate temperature conditions less than 18 °C (65 °F) will result in a decrease in product workability and slower cure rates.
Relative Air Humidity
Maximum 85% (during application and curing)
Dew Point
Substrate must be at least 3 °C (5 °F) above the dew point to reduce the risk of condensation, which may lead to adhesion failure or “blushing” on the floor finish. Be aware that the substrate temperature may be lower than the ambient temperature.
Substrate Temperature
Minimum 10 °C (50 °F) Maximum 30 °C (85 °F)
Do not apply while ambient and substrate temperatures are rising, as pinholes may occur. Ensure there is no vapour drive at the time of application. Refer to ASTM D4263, may be used for a visual indication of vapour drive.
Substrate Moisture Content
Moisture content of concrete substrate must be less than 4 % (pbw – part by weight) as measured with a Tramex® CME/CMExpert type concrete moisture meter on mechanically-prepared surface according to this product data sheet (preparation to ICRI / CSP 3 - 4). Do not apply to concrete substrate with moisture levels greater than 4% (pbw – part by weight) as measured with Tramex® CME/CMExpert type concrete moisture meter. If moisture content of concrete substrate exceeds 4 % (pbw – part by weight) as measured with Tramex® CME/CMExpert type concrete moisture meter, use Sikafloor®-1610 or Sikafloor®-81 EpoCem®CA or Sikafloor®-22 NA PurCem.
ASTM F2170 testing is not a substitute for measuring substrate moisture content with a Tramex® CME/CMExpert type concrete moisture meter as described above. When relative humidity tests for concrete substrate are conducted per ASTM F2170 for project specific requirements, values must be ≤ 85 %. If values exceed 85 % according to ASTM F2170, use Sikafloor®-1610 or Sikafloor®-81 EpoCem®CA or Sikafloor®-22 NA PurCem.
Pot Life
10 °C (50 °F) | 20 °C (68 °F) | 30 °C (86 °F) |
~60 minutes | ~30 minutes | ~15 minutes |
Curing Time
10 °C (50 °F) | 20 °C (68 °F) | 30 °C (86 °F) | |
Foot Traffic | ~2 days | ~1 day | ~12 hours |
Light Traffic | ~3 days | ~2 days | ~1 day |
Full Cure | ~7 days | ~7 days | ~5 days |
Curing time will vary according to air and substrate temperatures and relative humidity.
Freshly applied material should be protected from dampness, condensation and water for at least 24 hours.
Mechanical, chemical & physical properties will be fully achieved at full cure.
Waiting Time / Overcoating
10 °C (50 °F) | 20 °C (68 °F) | 30 °C (86 °F) | |
Sikafloor®-156 & Sikagard®-381 | ~24 hours to ~72 hours | ~6 hours to ~48 hours | ~8 hours to ~24 hours |
Sikagard®-381 & Sikagard®-381 | ~24 hours to ~48 hours | ~12 hours to ~24 hours | ~6 hours to ~12 hours |
Consumption
Coating without aggregates (48 mil)
Sikafloor®-156 Primer (8 mil) | 5 m2/L (203 ft2/US gal.) |
Sikagard®-381 Finish Coat (40 mil) | 1 m2/L (40 ft2/US gal.) |
Self-leveling coating with aggregates 2.7 mm (108 mil)
Sikafloor® 156 Primer (8 mil) | 5 m2/L (203 ft2/US gal.) |
Self-levelling mortar* (100 mil) / A+B+ #70 silica sand | 0.4 m2/L (16 ft2/US gal.) |
10 L unit (2.64 US gal.) of Sikagard®-381 mixed with 2.0 L (3.2 kg) (0.52 US gal.) # 70 silica sand will produce 11.18 L (2.94 US gal.) of self-levelling, ready-to-use mortar.
Add # 70 oven-dried silica sand to the mixed Sikagard®-381, at the following rates:
20 °C - 30 °C (68 °F - 86 °F) | Add ~20 % by weight |
15 °C - 20 °C (59 °F - 68 °F) | Add ~10 % by weight |
10 °C - 15 °C (50 °F - 59 °F) | Add 0 % |
The influence of colour selection should be allowed for in material consumption/coverage. Light or bright colours may require higher wet film thicknesses or additional coats to achieve desired opacity.
SUBSTRATE PREPARATION
The surface must be clean, dry and sound. Remove dust, laitance, grease, oil, dirt, curing compounds, impregnations, waxes, foreign particles, coatings and disintegrated particles by any appropriate mechanical means, in order to achieve a profile equivalent to ICRI-CSP 3-4. Concrete compressive strength should be at least 25 MPa (3625 psi) at 28 days and at least 1.5 MPa (218 psi) in tension at the time of Sikagard®-381 application.
MIXING
Mix Ratio - A:B = 3.48:1 by volume
Do not hand mix Sikafloor® materials. Mechanically mix only.
Do not thin this product. Addition of thinners (e.g. water, solvent, etc.) will slow cure and reduce ultimate properties of this product. Use of thinners will void any applicable Sika® warranty.
Pre-stir each component to ensure all soft settling is dispersed, solids are evenly distributed and even colours and consistencies are achieved within each component. Empty Component A (Resin) in the correct mix ratio into B (Hardener). Mix the combined components for at least three (3) minutes using a low speed drill (300 - 450 rpm) and Exomixer® or Jiffy type paddle suited to the volume of the pail to minimize entrapped air. Be careful not to introduce any air bubbles while mixing. Make sure the contents are completely mixed to avoid any weak or partially cured spots in the coating. During the mixing operation, scrape down the sides and bottom of the container with a flat or straight edge trowel at least once to ensure complete mixing. When completely mixed, Sikagard®-381 should be uniform in colour and consistency. Mix only that quantity you can use within its pot life.
NOTE: Depending on the required application and once the binder has been thoroughly mixed, gradually add oven dried silica sand size #70 (0.1 - 0.3 mm). For ramps and inclined surfaces, add 1 - 2 % by weight of Extender T, as required. Mix until uniform in colour and consistency.
Sikagard®-381 can also be applied as a neat coating without adding any aggregates.
APPLICATION
Primer - Apply Sikafloor®-156 using a brush or roller, to cover a surface of 5 m2/L (203 ft2/US gal.). Rough surfaces must be leveled with Sikafloor®-156 mortar overlay. Wait until primer coating is dry before applying Sikagard®-381.
Wearing Layer - Apply Sikagard®-381 evenly using a serrated or notched spreader to a uniform thickness. Then, roll the surface of Sikagard®-381 with a spiked roller to remove entrapped air.
Note: If the Waiting/ Recoat time has passed (refer to Technical Data section) the previous coat must be lightly sanded, to remove all gloss; vacuum cleaning and solvent wiping will be necessary to remove all traces of dust. The surface should be a uniform dullness, with no gloss present after clean-up and before applying the next coat.
CLEAN UP
Clean all tools and equipment immediately after use with Sika® Epoxy Cleaner. Once hardened, material can only be removed mechanically.