Sika® MB
Sika® MB is a 2-component, solvent free, low viscosity, epoxy for use under floor covering products, self-levelling underlayments, floating floors and other flooring systems that require protection from subfloor moisture.
- Solvent-free (~100% solid content)
- Easy roller applied application, low viscosity
- Convenient, easy to mix packaging
- Shorter construction periods
- Excellent penetration and stabilization of the substrate
- Reduction of adhesive consumption
- Suitable for use on floors with radiant heating
- Compatible with SikaBond® flooring adhesives, SikaLevel® products
- Can be used below floating floors
- Class I vapor retarder at 0.06 Perm (1 coat)
Usage
- Moisture barrier to help control moisture propagation in cementitious substrates with a moisture content not exceeding 6% (by Tramex meter), residual moisture up to 100% RH (using ASTM F2170) or 25 lbs. per 1,000 sq.ft. (11.34 kg per 92.9 m2) per 24 hours (using a anhydrous calcium chloride test ASTM F1869)
- For substrate consolidation on concrete, cement and gypsum screeds
- Adhesion promoter for old and new adhesive residues in conjunction with other Sika® products
- Suitable on concrete, cement, self-levelling and gypsum substrates, OSB, plywood, quarry and terrazzo tiles, water-soluble adhesive and cutbacks
Advantages
- Solvent-free (~100% solid content)
- Easy roller applied application, low viscosity
- Convenient, easy to mix packaging
- Shorter construction periods
- Excellent penetration and stabilization of the substrate
- Reduction of adhesive consumption
- Suitable for use on floors with radiant heating
- Compatible with SikaBond® flooring adhesives, SikaLevel® products
- Can be used below floating floors
- Class I vapor retarder at 0.06 Perm (1 coat)
Packaging
2.64 gal. (10 L) pail
Color
Blue
Product Details
ENVIRONMENTAL INFORMATION
LEED V4.1 California Department of Public Health (CDPH) Standard Method v1.2: Private Office, School Classroom, and Residential
APPROVALS / STANDARDS
Meets ASTM F3010
Chemical Base
Epoxy resin
Shelf Life
24 months from the date of production if stored properly
Storage Conditions
The product must be stored in original, unopened and undamaged sealed packaging in dry conditions and protected from direct sunlight at temperatures between 50°F and 77°F (10°C and 25°C).
Condition material between 65°F and 75°F (18°C and 24°C) before using
Density
~9.18 lbs/gal (~1.10 kg/L)
System Structure
Application | Recommended coatings | Results in |
Moisture barrier only | min. 1 | Mirror like finish |
Substrate consolidation only | min. 1 | Good penetration |
Adhesion promotion only | min. 1 | Mirror like finish |
Moisture barrier + substrate consolidation | min. 2 | Mirror like finish |
Moisture barrier + adhesion promotion | min. 2 | Mirror like finish |
Note: MUST produce a monolithic, pinhole-free finish with a continuous film. The need for multiple coats is directly related to surface absorption.
Shore D Hardness
~83 (7 days) | (ASTM D2240) |
Compressive Strength
~10,000 psi (~69 MPa) | (7 days at 73°F (23°C) and 50% RH) |
Permeability to Water Vapor
~0.06 g/m2-24h-mmHg (~0.06 Perm) | (ASTM E96) |
Service Temperature
-40°F (-40°C) to 158°F (70°C)
Application
Ambient Air Temperature
50°F (10°C) min. / 86°F (30°C) max.
Relative Air Humidity
85% RH max. (during application and curing)
Dew Point
Beware of condensation!
The substrate must be at least 5°F (3°C) above measured dew point to reduce the risk of condensation on the surface of the applied product.
Substrate Temperature
During laying and until Sika® MB has fully cured, the substrate temperature should be between 50°F and 86°F (10°C and 30°C).
Pot Life
Temperature | Time |
50°F (10°C) | ~60 minutes |
68°F (20°C) | ~30 minutes |
86°F (30°C) | ~15 minutes |
Cure Time
Prior to walking on primer/or for applying SikaBond® or SikaLevel® allow:
Temperature | Time |
50°F (10°C) | ~18 hours |
73°F (23°C) | ~8 hours |
86°F (30°C) | ~6 hours |
Times are approximate and will be affected by changes in ambient conditions, particularly temperature and relative humidity.
Coverage
Application | Coverage per pail |
Moisture barrier | 250-300 sq.ft. (23.23-27.87 m2) |
Adhesion promoter or surface consolidator | 400-450 sq.ft. (37.16-41.81 m2) |
These are estimated coverages and additional material may be required based on substrate porosity/profile, material wastage or any other variations.
SUBSTRATE QUALITY
The substrate must be sound and of sufficient compressive strength (minimum 1,160 psi (8 MPa)) with a minimum pull-off strength of 116 psi (0.8 MPa).
Substrate must be clean, dry, sound, homogeneous and even, free of all contaminants such as oil, grease, dust, and loose or friable particles. Paint, wax, curing and sealing compounds, laitance, and other poorly adhering contents that will interfere with the adhesion of Sika® MB must be mechanically removed.
Note: Before overall installation begins, Sika recommends the application of several small test patches to determine primer application requirements and acceptability of final product performance.
SUBSTRATE PREPARATION
- All substrate must have an open textured surface to allow Sika® MB to penetrate the surface (i.e. blast cleaning, grinding are considered acceptable means to achieve the desired surface profile. Acid and chemical etching are NOT acceptable).
- Concrete substrate must have a concrete surface profile of CSP 3-4.
- At least 50% of the surface area must be cleared of residual adhesive and cutbacks (i.e. by grinding or mechanical substrate preparation).
- Old cutback can contain asbestos which is dangerous for the health so do not grind, sand or blast. Refer to the Resilient Floor Covering Institute’s publication “recommended work practice for removal of resilient floor coverings” for instruction.
- Repair with Sika® Level SkimCoat before priming.
- On fiber reinforced concrete, fibers should be flamed off the surface prior to application of Sika® MB as a moisture barrier.
- All moving joints and moving cracks must be honored up through the floor preparation and floor covering installation, finishing with an appropriate Sika flexible sealing compound. Dormant hairline cracks can be covered with Sika® MB. Dormant joints and dormant cracks greater than a hairline that will not be honored must be pre-filled in strict accordance with the installation instructions provided by the Sika Technical Service Department. Dormant hairline cracks can be covered with an appropriate Sika flexible sealing compound. Once the dormant cracks and dormant joints have been properly filled, broadcast sand to refusal, and allow these areas to cure thoroughly. Remove all excess sand before proceeding with the Sika® MB installation.
- All dust, loose and friable material must be completely removed and cleaned with an industrial vacuum from all surfaces before application of the product.
MIXING
- Add one full can of Part A to one full can of Part B then mix with an electric drill and mixing paddle (Jiffy Mixer type) at a low speed to reduce air entrainment (300–400 rpm). Using a paint stick or similar is NOT sufficient to mix the primer.
- A minimum mixing time of 3 minutes shall be observed; mixing shall continue until a homogeneous mix has been achieved.
- Scrape sides of pail with paint stick or paddle to ensure all contents are thoroughly mixed together.
- Unmixed material applied to the floor will not cure properly.
APPLICATION
Apply Sika® MB uniformly (crosswise) to the substrate using a 3/8” nap roller, ensuring that a monolithic coat is achieved over the entire surface.
CLEANING OF TOOLS
Clean all tools and application equipment with cleaning solvent (Xylene, MEK or other similar solvent). Hardened/cured material can only be removed mechanically.
FAQ
Excess moisture can weaken adhesion, cause floor coverings to lift, and lead to mold growth. Before leveling, conduct a moisture test. If moisture levels exceed acceptable limits, apply Sika® MB as a moisture barrier to protect the installation.
Sika® offers high-quality products such as Sika® Level-325, a cementitious self-leveling underlayment, and Sika® Level SkimCoat, ideal for minor surface imperfections. For improved adhesion, Sika® Level-01 Primer Plus helps ensure a strong bond, while Sika® MB acts as a moisture barrier in high-humidity environments.