Product Description
Bona R851® Adhesive
Bona R851® is a silane-based wood flooring adhesive that provides exceptional “green grab
strength. Its elastomeric characteristics allow the adhesive to move with the wood as it expands
and contracts over the life of the floor.
Key Benefits
• Easy to apply – No arm fatigue
• Unsurpassed ridge stability provides maximum adhesive transfer
• Easy to clean
• Zero VOC
• GREENGUARD Gold Certified
PHYSICAL CHARACTERISTICS
Ingredients – Calcium carbonate, silane modified
prepolymer, plasticizers, amorphous silica
Base – Silane Modified-Prepolymer
Color – Cream
Viscosity – 64 Pa/*s at a shear rate of 5/1 sec (coneplate rheometer)
Density – 13.6 lbs./gallon
VOC Content – ZERO VOC
Max Shear Strength – 340psi (at final cure; lap shear
test, 1mm gap)
Elongation – 180-220%
Water Vapor Permeability - < 0.7 g/m2-24 hourmmHG @ 2000g/m2
Sound Reduction Rating – 71dB IIC, STC 65dB (6”
concrete slab with ceiling) per ASTM E492-09 and
ASTM E90-04
Moisture Levels – Moisture protection up to 18lbs or
95% RH, 6% Tramex. For maximum moisture
protection ensure 100% transfer of adhesive to both
subfloor and flooring.
Odor – Non-offending
Flash Point – >100º C (212ºF) (Pensky-Martens)
Stability – 12 months from date of manufacture in
unopened, original packaging
Packaging – 3-gallon (17.14 kg) containers
APPLICATION CHARACTERISTICS
Spread Rating – Easy to spread, maintains excellent
ridge stability
Open Time- 60 minutes@70oF and 50%RH*
Coverage – See “Trowel Notch Requirements” for
spread rate
Curing – Light foot traffic - 8-10 hours
Furniture, fixtures - 12-24 hours
Unfinished floor sanding - after 24 hours
*Dependent of temperature and humidity. Higher
humidity decreases open time while lower humidity
increases open time.
RECOMMENDED USE
Commercial and residential. Use with solid or engineered prefinished and unfinished flooring; on,
above or below grade. May be used on both wood and concrete substrates.
ACCLIMATION AND SITE CONDITIONS
Building climate control system must be functioning with a temperature of 65ºF–95 ºF and maximum relative humidity of 65% for 72 hours before flooring is installed, during installation, and for 72 hours after installation. Ideal conditions are 65-70oF and 45-55% RH. Acclimate Bona R851 adhesive to room temperature of the installation, usually overnight. Moisture testing: For concrete slabs, using standard application, conduct moisture testing per ASTM test methods F 1869 Test for Measuring Moisture Vapor Emission Rate (MVER) of Concrete Subfloor Using Anhydrous Calcium Chloride, and/or F 2170 Test Method for Determining Relative Humidity in Concrete Floor Slabs Using In Situ Probes. Contact ASTM International to obtain copies of the test methods before proceeding. MVER using ASTM F 1869(Calcium chloride test) shall not exceed 12 lbs/24 hours/1000 square feet. Relative Humidity using ASTM F 2170 (RH Probe test) shall not exceed 85%. If MVER readings exceed 12 lbs. or 85% but are less than 18 lbs. or 95%, use the Bona R540 Moisture Barrier/Primer (See label for detailed instructions) or use a Moisture Barrier Plus (MBP) clip-on trowel with any Bona trowel and spread the adhesive at a coverage rate of 30-35 square feet per gallon. For maximum moisture protection ensure 100% transfer of adhesive to both subfloor and flooring. To ensure proper coverage use a new clip-on trowel for every pail of adhesive. When using a Tramex measuring device to identify moisture levels in cementitious based substrates, find the highest reading in the area to be installed. As a general guideline for floors with no infloor heating system, if the Tramex reading is below 4%, the Bona Moisture Barrier Clip-On Trowel or the Bona R540 Moisture Barrier/Primer will not be necessary. If the reading is between 4% and 6%, either use the Moisture Barrier Plus (MBP) Clip-On Trowel or apply Bona R540 Moisture Barrier/Primer prior to adhesive application. For wood substrates, follow flooring manufacturer’s guidelines including moisture content and required moisture measuring methods.
SUBSTRATE PREPARATION
Substrate must be clean, smooth, dry, free of loose material and structurally sound, with the surface slightly textured (similar to a light broom finished concrete) for best adhesion. Remove adhesive residue, paint, concrete curing compounds or other contaminants that may affect adhesive bond. Sandblasting, shot blasting or scarifying may be necessary to completely remove some of these residues. Surface cracks, grooves, depressions, control joints or other non-moving joints, and other irregularities must be filled or smoothed with a Portland Cement based patching and leveling compound. Substrate must be level to 3/16” in a 10-foot span. Do not install wood flooring before the compound has fully cured. Do not install over expansion joints or other moving joints in a concrete slab. Slab temperaturemust be between 55°F and 95°F. Suitable substrates include concrete, plywood, Warmboard®, cork, particle or chip board, stone, ceramic, terrazzo, radiant heat flooring (refer to manufacturer’s recommended installation instructions), and dry above-grade gypsum underlayment, recycled-rubber underlayment.
PRODUCT LIMITATIONS
Bona R851 will not prevent moisture-related damages to wood flooring originating from the top, sides or ends of flooring (water leaks, puddles, hydrostatic head, etc.) nor does it eliminate other moisture or installation related issues such as improper acclimation of flooring or the effects of jobsite temperature and humidity.
DO NOT USE BONA R851
• On wet, contaminated or friable surfaces
• Over concrete curing compounds, sealers or
other surface treatments that could affect
adhesion
• On areas subject to hydrostatic head
• On cutback residue, or over vinyl/VCT
• On chemically treated woods (stain,
preservatives, etc.)
• As a leveling compound
SPREADING ADHESIVE AND LAYING FLOORING
Spread adhesive on the substrate while holding the Bona trowel at a 90° angle, using a smooth
semicircular motion. Do not leave any puddles of adhesive. Set the flooring into the adhesive while the adhesive is still wet. At the start of the job, pull a freshly laid board to ensure 100% transfer. This can be repeated a second time, mid-installation, to ensure consistency. Do not allow more than 60 minutes of open time before setting flooring into the adhesive. (at 70oF and 50% RH; higher humidity can decrease open time, lower humidity can increase open time). DO
NOT SET FLOORING INTO ADHESIVE THAT HAS SKINNED OVER, REMOVE ADHESIVE AND REAPPLY.
BACK TROWEL METHOD
Utilizing the flat side of the Bona® 1500g trowel or the Bona® 1250g trowel, skim coat Bona R851 onto subfloor creating a smooth surface free of voids. While the skim coat of adhesive is still wet, apply Bona R851 with either trowel.
CLEAN-UP
Clean adhesive from the surface of the floor while wet. Use mineral spirits on a clean white cloth.
STORAGE
Store in a climate controlled environment. Do not store for extended periods in excess of 90ºF. Freeze thaw stable.
