SikaBond®-T21

SikaBond®-T21 may be used for solid and engineered wood floors (strips, long strips, planks, panels, boards), mosaic parquet, industrial parquet, wood paving (residential) as well as particle board and plywood.

Chemically treated woods (ammonia, wood stain, timber preservatives, etc), woods that have been pre-sealed on the back side) or woods with high oil content must be tested with SikaBond®-T21 by the applicator and verified as suitable prior to proceeding with work.

SikaBond-T21® contains no water and it will not cause swelling of wood flooring.

SikaBond®-T21 is especially good for problematic woods such as beech and bamboo.

Yes, SikaBond-T21® bonds solid wood flooring up to 19 mm (3/4 in) thick and 20 cm (8 in) wide

Yes, SikaBond-T21® bonds engineered planks up to 35.6 cm (14 in) wide directly to concrete with no length limitations.

SikaBond®-T21 eliminates sleepers and plywood over concrete and gypsum substrates.

Yes, SikaBond®-T21 is compatible with the in-floor, radiant heating.

For proper coverage, use as a minimum, a P5 trowel.

P5 Trowel: approx. 1.1 m2 - 1.2 m2/L (45 ft2 - 50 ft2/US gal) SikaBond®-T21 requires, as a minimum, a P5 trowel for application, with larger notch sizes also being acceptable.

Use all-in-one SC+MB trowel or ¼ in x 1/4 in V-notch trowel (for moisture vapour and sound reduction membrane and bonding).

SC+MB Trowel or 1/4” x 1/4” V-notch: approx. 0.73 m2 - 0.86 m2/L (30 ft2 - 35 ft2/US gal) required for vapour and sound retarding membrane. SikaBond®-T21 requires the use of a SC+MB or 1/4 x 1/4 V notch trowel for application, with larger notch sizes also being acceptable.

4.0 mm/24 hours.

Floor may accept light foot traffic after:

• 6 - 8 hrs at 1.1 - 1.2 m2/L (45 - 50 ft2/US gal) (P5 trowel)
• 12 h at 0.73 - 0.86 m2/L (30 - 35 ft2/US gal) (SC+MB trowel) (depending on climatic conditions and adhesive layer thickness)

~ 45 - 60 minutes

SikaBond®-T21 can generally be used without priming on properly prepared, structurally sound concrete, cement floors, particle board, ceramic tiles, plywood, and hardwood. Sika recommends the use of Sika® Primer MBCA over any dry, gypsum-based subflooring to enhance surface strength. Maximum acceptable floor variation is 5 mm in 3.05 m (3/16” in 10’).

Preparation is a critical step in the installation process and will ensure a successful long-term tenacious bond. All concrete, cement screed and gypsum-based subfloors must be structurally sound, clean, dry, smooth, free of voids, projections, loose materials, oil, grease, sealers, and other surface contaminants. Remove laitance or weak areas mechanically. For application over ceramic tiles, it is necessary to grind tile surfaces and clean thoroughly with an industrial vacuum. For substrates with old well bonded adhesive or adhesive residue use Sika® Primer MBCA

If surface contains asphalt (cutback) adhesive, follow the Resilient Floor Covering Institute’s Recommended Work Practices for removal. When the asphalt (cutback) adhesive is sufficiently removed, use the Sika® Primer MBCA to help promote adhesion to the subfloor or use a Sika® Level primer and levelling compound over the cutback residue. SikaBond®-T21 will adhere to most common patching/levelling compounds. Due to differences in asphalt based adhesive types and performance capabilities, the applicator must verify that preparation of the surface is sufficient prior to using Sika® Primer MBCA or the Sika® Level compound. For unknown substrates, please contact your Sika Canada Technical Sales Representative.

During laying and until SikaBond®-T21 has fully cured, substrate temperature should be greater than +15 °C (59 °F) and in case of in floor heating systems, less than +20 °C (68 °F). For substrate temperatures, standard construction rules are relevant.

Room temperature must be between +15 °C (59 °F) and +35 °C (95 °F). For ambient temperatures, the standard construction rules are relevant.

Substrate Humidity: For use as an adhesive only, SikaBond®-T21 is not affected by moisture or vapour transmission. For protection of the wood follow the wood floor manufacturer’s requirements for subfloor moisture. If substrate is not acceptable, use SikaBond®-T21 at recommended coverage rate as an all-in-one system or use Sika® Primer MBCA. See Sika® Primer MBCA Product Data Sheet for proper instruction.

For use as an adhesive and membrane: Concrete must be visibly dry. Inspect for any visible signs of moisture on concrete or wetness at details and junctures, i.e., at base of drywall. Concrete and cement-based underlayment must be fully cured and free of any hydrostatic and/or moisture problems.

Between 40 % and 70 % during installation is best for adhesive. See wood floor manufacturers for wood requirements.