SikaBond®-T21
All-in-one, polyurethane-based, wood flooring adhesive, moisture vapour and sound reduction membrane
SikaBond®-T21 is a one-component, low-VOC, permanently elastic, super strong, very low permeability, moisture-cured, vapour-retarding, crack-bridging polyurethane adhesive and sound reduction membrane, all-in-one, for full surface wood floor bonding.
- 270 % Elongation
- Extremely easy to trowel
- Unlimited subfloor moisture vapour protection
- No moisture testing required - a dry to touch substrate is the only requirement
- Single material capable of operating as a wood floor adhesive, vapour retarding membrane and sound reduction layer
- Excellent Green Grab
- Suitable for most common types of wood flooring
- Especially good for problematic woods such as beech and bamboo
- Bonds solid wood flooring up to 19 mm (¾ in) thick and 200 mm (8 in) wide, and engineered planks up to 350 mm (14 in) wide directly to concrete without length limitations
- Low odour
- Suitable for in-floor radiant heat installation
- Permanently elastic – allows planks to expand and contract without damage to the adhesive
- Crack-bridging
- Tenacious bond
- Contains no water
- Eliminates sleepers over concrete
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 particleboard and plywood.
Advantages
- 270 % Elongation
- Extremely easy to trowel
- Unlimited subfloor moisture vapour protection
- No moisture testing required - a dry to touch substrate is the only requirement
- Single material capable of operating as a wood floor adhesive, vapour retarding membrane and sound reduction layer
- Excellent Green Grab
- Suitable for most common types of wood flooring
- Especially good for problematic woods such as beech and bamboo
- Bonds solid wood flooring up to 19 mm (¾ in) thick and 200 mm (8 in) wide, and engineered planks up to 350 mm (14 in) wide directly to concrete without length limitations
- Low odour
- Suitable for in-floor radiant heat installation
- Permanently elastic – allows planks to expand and contract without damage to the adhesive
- Crack-bridging
- Tenacious bond
- Contains no water
- Eliminates sleepers over concrete
Packaging
15.14 L (4 US gal) pail
Colour
Light brown
Product Details
ENVIRONMENTAL INFORMATION
- Contributes towards satisfying LEED® v4 EQ Credit - Low-Emitting Materials
- Contributes towards satisfying LEED®v4 MR Credit - Building Product Disclosure and Optimization - Sourcing of Raw Materials (Option 1: Raw material source and extraction reporting):
APPROVALS / CERTIFICATES
- Independently tested to -STC 62 (ASTM E-90) [168 mm (6 in)] concrete slab, 5/8 in (19 mm) suspended gypsum ceiling)
- Reduction of Impact Sound Δ IIC = 21 (ASTM E-2179)
Shelf Life
12 months from date of manufacture, in its original, undamaged and sealed container.
Storage Conditions
Store dry at temperatures between 10 °C and 25 °C (50 °F and 77 °F) and protect from direct sunlight.
Density
Water Vapour Permeability < 4 g/m2-24h-mmHg per ASTM E96 (Standard Test Method for Water Vapor Transmission of Materials)
-
Specific Gravity 1.18 kg/L (9.85 lb/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 73 °F (23 °C) and 50 % R.H.) |
Shear Strength
1.03 MPa (150 psi) using 1 mm adhesive thickness | (28 days at 73 °F (23 °C) and 50 % R.H.) |
Service Temperature
-40 °C to 70 °C (-40 °F to 158 °F)
Application
Sag Flow
Consistency: Spreads very easily
Substrate Moisture Content
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 or Sika® MB. See Product Data Sheet for proper instruction.
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.
Curing Rate
4.0 mm/24 h at 23 °C (73 °F) and 50 % R.H. |
Floor may accept light foot traffic after:
- 6 to 8 h 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)
Floor can be sanded after 18 hours
Skin Time / Laying Time
~ 45 to 60 minutes | at 23 °C (73 °F) and 50 % R.H. |
Consumption
| For use as an adhesive only: |
|
For use as an adhesive and membrane:
Use All-in-One SC+MB trowel or 1/4” x 1/4” 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 - 0.86 m2/L (30 - 35 ft2/US gal) required for vapour and sound retarding membrane.
SikaBond®-T21 requires the use of an SC +MB or 1/4 x 1/4 V notch trowel for application, with larger notch sizes also being acceptable.
P5 trowels should be used at 90° angle to the subfloor to achieve the stated coverages, while a SC+MB trowel or 1/4” x 1/4” V-notch trowel should be used at 45° angle.
The Applicator is responsible for periodic inspection of the trowel to check for excessive wear. If the trowel is found to be a defective, it should be replaced immediately to assure recommended coverage.
In cases of uneven substrates, it may be necessary to use a trowel with larger notches to increase the thickness of the adhesive layer. Avoid hollow sections or bare patches. Excessive amounts of adhesive may cause wood flooring to slide.
Coverage must be monitored to ensure accuracy of application. Improper trowel angle may prevent proper coverage.
SUBSTRATE PREPARATION
The subfloor must be must be structurally sound, clean, dry, level and free from oils, bituminous materials, curing compounds, grease, dust, loose particles, paint and other poorly adhering material. SikaBond®-T21 can generally be used without priming on properly prepared, structurally sound concrete, cement floors, particleboards, 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 in 10 ft).
Preparation is a critical step in the installation process and will ensure a successful, long-term, tenacious bond. Concrete substrates must be structurally sound, clean, dry, level, free of voids, projections, loose materials. They must be free of oil, grease, sealers and other surface contaminants or any contaminants or conditions that may affect adhesion or overall product performances. They should be thoroughly cleaned with an industrial vacuum agitating the surface with a brush attachment. For substrates with old, well-bonded adhesive or adhesive residue, use Sika® Primer MBCA. Consult the relevant Product Data Sheet for application instructions and proper details.
For application over ceramic tiles, it is necessary to grind tile surfaces, removing any glaze and producing a matt, fine gripping surface and then clean thoroughly with an industrial vacuum equipped with a brush attachement.
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 sub-floor 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.
Substrate Temperature: 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, the standard construction rules are relevant.
Air Temperature: 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 moisture 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 underlayments must be fully cured and free of any hydrostatic and/or moisture problems.
Relative Air Humidity: Between 40 % and 70 % during installation is best for adhesive. See wood floor manufacturer for wood requirements.
CLEAN UP
All tools should be cleaned immediately after use with Sika® Urethane Cleaner and Thinner. Any adhesive that is permitted to cure on the tools will need to be removed by mechanical means. Use a dry cloth and Sika® Hand Cleaner towels to remove adhesive from pre-finished wood surfaces before it cures. Finger prints or small amounts of adhesive residue can be removed from pre-finished wood using the towels. Sika® Hand Cleaner towels use a citrus based cleanser that will not harm the floor finish. Remove any adhesive residue from hands using the Sika® Hand Cleaner towels.
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.