SikaBond®-T21
All-in-One Low VOC Wood Flooring Urethane Adhesive, Unlimited Moisture Vapour and Sound Reduction Membrane
SikaBond®-T21 is a one-component, low VOC, permanently elastic, super strong, very low permeability moisture-cure polyurethane adhesive, vapour retarding, crack bridging and sound reduction membrane all-in-one for full-surface wood floor bonding.
- 270 % Elongation
- Single material capable of operating as a wood floor adhesive, vapour retarding membrane and sound reduction layer
- Extremely easy to trowel
- No moisture testing required - a dry to touch substrate is the only requirement
- Crack bridging
- Low odour
- Excellent Green Grab
- Bonds solid wood flooring up to 19 mm (¾ in) thick and 203 mm (8 in) wide, and engineered planks up to 350 mm (14 in) wide directly to concrete without length limitations
- Suitable for common types of wood flooring
- Creates sound reduction layer
- Especially good for problematic woods such as beech and bamboo
- Contains no water
- Eliminates sleepers and plywood over concrete
- Permanently elastic – allows planks to expand and contract without damage to the adhesive
- Tenacious bond
Usage
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 chip boards and plywood. Once cured, SikaBond®-T21 will generate a super strong bond to a variety of substrates for glue down installations and at the same time form a membrane which reduces moisture vapour transmission from the subfloor and sound reduction membrane.Advantages
- 270 % Elongation
- Single material capable of operating as a wood floor adhesive, vapour retarding membrane and sound reduction layer
- Extremely easy to trowel
- No moisture testing required - a dry to touch substrate is the only requirement
- Crack bridging
- Low odour
- Excellent Green Grab
- Bonds solid wood flooring up to 19 mm (¾ in) thick and 203 mm (8 in) wide, and engineered planks up to 350 mm (14 in) wide directly to concrete without length limitations
- Suitable for common types of wood flooring
- Creates sound reduction layer
- Especially good for problematic woods such as beech and bamboo
- Contains no water
- Eliminates sleepers and plywood over concrete
- Permanently elastic – allows planks to expand and contract without damage to the adhesive
- Tenacious bond
Packaging
15.14 l (4 US gal) pail
Colour
Light Brown
Product Details
ENVIRONMENTAL INFORMATION
| LEED® EQc 4.1 CDPH Standard Method v1.2 | SCAQMD, Rule 1168 (25 g/L limit) | BAAQMD, Reg. 8, Rule 51-226 (20 g/L limit) |
| passes | passes | passes |
APPROVALS / CERTIFICATES
- Independently tested to -STC 62 (ASTM E-90) 168 mm ((6 in.) concrete slab, 19 mm (5/8 in.) suspended gypsum ceiling
- Independently tested to FIIC 52 (ASTM E-989) (8 in. (203 mm) concrete slab, without ceiling
- Reduction of Impact Sound Δ IIC = 21 (ASTM E-2179)
Composition / Manufacturing
1-component polyurethane, moisture curing
Shelf Life
12 months from date of production
Storage Conditions
Store in undamaged original sealed containers, in dry conditions and protected from direct sunlight at temperatures between 10 °C (50 °F) and 25 °C ( 77 °F)
Density
Water Vapour Permeability < 4 g/m2-24h-mmHg per ASTM E-96 (Standard Test Method for Water Vapor Transmission of Materials)
-
Specific Gravity 1.18 kg/L (9.85 lbs/gal)
Shore A Hardness
| 50 | (28 days at 73 °F (23 °C) and 50 % R.H.) |
Tensile Strength
| 1.03 MPa (150 psi) | (28 days at 23 °C ( 73 °F) and 50 % R.H.) |
Shear Strength
| 1.03 MPa (150 psi) using 1 mm adhesive thickness | (28 days at 23 °C (73 °F) and 50 % R.H.) |
Service Temperature
Between -40 °C (-40 °F) and 70 °C (158 °F)
Application
Sag Flow
Consistency: Spreads very easily
Relative Air Humidity
Between 40 % and 70 % during installation is best for adhesive. See wood floor manufacturer for wood requirements.
Substrate Temperature
During laying and until SikaBond®-T21 has fully cured, substrate temperature should be greater than 15 °C (60 °F) and in case of radiant floor heating, less than 20 °C (70 °F). For substrate temperatures, the standard construction rules are relevant.
Substrate Moisture Content
For use as an adhesive and moisture membrane:
Concrete must be visibly dry. Inspect for any wetness at base of drywall or visible signs of moisture on concrete. Concrete and cement-based underlayments must be fully cured and free of any hydrostatic and/ or moisture problems. When properly applied in accordance with Sika® guidelines, SikaBond®-T21 provides unlimited moisture vapour protection.
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 All-in-One. See Technical Data Sheet for proper instruction.
Curing Rate
| 4.0 mm/24 h | (at 23 °C (73 °F) and 50 % R.H.) |
Floor may accept light foot traffic:
After 6–8 hours at 1.10 to 1.22 L/m2 (45 to 50 ft2/gal) (6.3 mm (1/4 in) x 6.3 mm (1/4 in) V-notch. 6.3 mm (1/4 in) x 6.3 mm (1/4 in) V-notch):
Floor can be sanded after 18 hours at 0.73 to 0.86 L/m2 (30 to 35 ft2/gal) (SC+MB trowel): after 12 hours (depending on climatic conditions and adhesive layer thickness).
Skin Time / Laying Time
| ~ 45–60 minutes | (at 73 °F (23 °C) and 50 % R.H.) |
Consumption
| FOR ALL-IN-ONE MOISTURE AND SOUND REDUCTION |
- For the installation of solid wood
Maximum thickness : 19 mm (3/4 in) _ Max Width: 20 cm (8 in).
|
| 6.3 mm x 6.3 mm x 6.3 mm V-notched trowel 0.73 to 0.85 m2/l (30 to 35 ft2/ US gal) |
- For the installation of engineered wood
Maximum thickness : 19 mm (3/4 in) _ Max Width: Ulimited
|
| 0.73 to 0.85 m2/l (30 to 35 ft2/ US gal) |
FOR USE AS AN ADHESIVE ONLY
- For the installation of solid wood
Maximum thickness : 19 mm (3/4 in) _ Max Width: 20 cm (8 in)
- For the installation of engineered wood
Maximum thickness : 19 mm (3/4 in) _ Max Width: Ulimited
|
| 4.7 mm x 3 mm x 3 mm V-notched trowel 1.10 to 1.22 m2/l (45 to 50 ft2/ US gal) |
FOR USE WITH SELECTED UNDERLAYMENTS
Cork or rubber underlayments A
|
| 3 mm x 3 mm x 3 mm square notched trowel 1.95 m2/l (80 ft2/ US gal) |
- Applicator is responsible for periodic inspection of the trowel to check for excessive wear. Worn trowels must be replaced immediately.
- In case of uneven substrates, it may be necessary to use a notched trowel with bigger notches (avert hollow sections).
- Coverage must be monitored to ensure accuracy of application. Trowel angle may prevent proper coverage. 4.7 mm (3/16 in) x 3 mm (1/8 in) x 3 mm (1/8 in) V-notch trowels should be used at 90° angle, SC+MB trowel or 6.3 mm (1/4 in) x 6.3 mm (1/4 in) V-notch. 6.3 mm (1/4 in) x 6.3 mm (1/4 in) V-notch trowels should be used at 45° angle to subfloor to get stated coverages.
- Trowel size is recommended to obtain proper coverage larger sizes are acceptable. Excessive amounts of adhesive may cause wood flooring to slide while placing. Coverage should be checking periodically during installation.
A SikaBond®-T21 is not compatible with rubber underlayment containing EPDM or similar substitutes.
NOTES ON INSTALLATION
Wood floor manufacturer’s requirements for room humidity levels and environmental control along with wood flooring acclimatization requirements must be strictly followed.
SikaBond®-T21 should be kept above 15 °C (59 °F) for best workability. Room temperatures should be between 15 °C (59 °F) and 32 °C (89 °F) during installation unless otherwise specified limitations by wood flooring manufacturer. Sufficient ambient moisture is necessary for proper curing. This said, if jobsite conditions are outside of flooring manufacturer’s recommendations, take necessary corrective actions as recommended by the floor manufacturer to address these issues.
SUBSTRATE PREPARATION
SikaBond®-T21 can generally be used without priming on properly prepared, structurally sound concrete, chipboards, ceramic tiles, plywood and hardwood. 20.6 MPa (3 000 psi) compressive strength is the minimum requirement needed for SikaBond wood floor installations, including glue-down wood floors, or glued/mechanically anchored subfloors. Concrete substrate must have a concrete surface profile of CSP 1-3. Maximum acceptable floor variation is 4.7 mm in 3 m (3/16 in, in 10 ft). Preparation is a critical step in the installation process and will ensure a successful long-term tenacious bond. All concrete, cement screed substrates 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 with a brush attachment.
CLEAN UP
All tools must be cleaned immediately after use with SikaBond® Remover or standard industry cleaning solvent. Any adhesive that is permitted to cure on the tool will need to be removed by mechanical means.
FAQ
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.
