Description
Bona R851 adhesive is a new generation silane-based wood flooring adhesive that provides exceptional green grab strength and unsurpassed final shear strength compared to competitive products. Bona R851 is easy to apply, easy to clean and has exceptional green grab. Water- and solvent-free, isocyanate-free and very low VOC’s.
Key Benefits:
- Excellent “green grab” means the flooring stays in place
- No “memory” floor seams will not move apart
- Rapid shear strength development flooring is ready for furniture and foot traffic in one day
- Easy to clean will not harm the finish on pre-finished floors; will not stain hands
- Easy to apply no arm fatigue
- Exceptional ridge stability provides maximum adhesive transfer
- GREENGUARD Indoor Air Quality Certified
- Moisture protection up to 15lbs or 85% RH
- Very low VOC meets the criteria for LEED EQc 4.1 (v. 2.1, 2.2, 3.0)
- California Proposition 65 Compliant
- Can be used with radiant heat systems
Bona R851
Technical Data Sheet
Rev 07/12/2019
This data sheet replaces all previous versions page 1/3
Adhesives
Bona R851 is a one-component, moisture curing, water and solvent free, silane-based adhesive for wood
floors. Bona R851 provides outstanding adhesion to a variety of surfaces, and allows for the natural
movement of wood flooring.
• Extended open time – 60 minutes@70oF and 50%RH*
• 1250G and Moisture Barrier Plus clip-on trowels included!
• Excellent “green grab” means the flooring stays in place
• No “memory” – Floor seams will not move apart
• Rapid shear strength development – Flooring is ready for furniture and foot traffic in one day
• Easy to clean – Will not harm the finish on pre-finished floors; will not stain hands
• Easy to apply – No arm fatigue
• Exceptional ridge stability provides maximum adhesive transfer
• GREENGUARD Indoor Air Quality Certified®
• Moisture protection up to 18lbs or 95% RH
• ZERO VOC – Meets the criteria for LEED EQc 4.1 (v. 2.1, 2.2, 3.0)
• California Proposition 65 Compliant
• Can be used with radiant heat systems
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 (cone-plate rheometer)
Density – 12.5-13.4 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 hour-mmHG @ 2000g/m2
Sound Reduction Rating – 71dB per ASTM E492-09 IIC (6” concrete slab with ceiling)
Moisture Levels – Moisture protection up to 18lbs or 95% RH, 6% Tramex or 5% CM
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.
• Commercial and residential. Use with solid or engineered prefinished and unfinished flooring; on,
above or below grade1
. May be used on both wood and concrete substrates2
.
1Read and follow flooring manufacturer instructions, recommendations and limitations as to the suitability
of a particular flooring product to certain jobsite conditions and installation methods.
2After proper site conditions, moisture testing results and substrate preparation have been met. See
“Directions for Use” for acceptable jobsite conditions.
DIRECTIONS FOR USE:
BEFORE USING, READ ALL DIRECTIONS AND MATERIAL SAFETY DATA SHEETS.
FOR TECHNICAL ADVICE: Call Bona US at 800-872-5515
ACCLIMATION AND SITE CONDITIONS: Building climate control system must be functioning with a
temperature of 65ºF – 80ºF and maximum relative humidity of 70% for 72 hours before flooring is installed,
during installation, and for 72 hours after installation. Acclimate Bona R851 adhesive to room temperature
of the installation, usually overnight.
Technical data
Directions
Recommended Use
Bona R851
Technical Data Sheet
Rev 07/12/2019
This data sheet replaces all previous versions page 2/3
Adhesives
MOISTURE TESTING: For concrete slabs, using standard application, conduct moisture testing per ASTM
test methods F1869 Test for Measuring Moisture Vapor Emission Rate (MVER) of Concrete Subfloor Using
Anhydrous Calcium Chloride and/or F2170 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 F1869 (Calcium chloride test) must not exceed 12 lbs/24 hours/1000
square feet. Relative Humidity using ASTM F2170 (RH Probe test) must not exceed 85%. If MVER
readings exceed 12 lbs. or 85% but are less than 18 lbs. or 95%, the following procedure may be
used. Attach the included Moisture Barrier Plus (MBP) clip-on trowel (AT0003020) to any Bona trowel and
spread the adhesive at a coverage rate of 30-35 square feet per gallon. 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, use the Tramex measuring device to find the highest reading in
the area to be installed and then run the CM testing method where you have recorded the highest reading.
As a general guideline for floors with no in-floor heating system, if the Tramex is below 4%, the Bona R540
will not be necessary and between 4% and 6%, Bona R540 will be required. However, the CM method must
be used to make final determination of concrete moisture levels. For moisture protection, ensure that 100%
coverage and transfer have been achieved. For moisture content and quality of substrates, the guidelines
of the wood floor manufacturer must be observed. 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 for best adhesion (similar to a light broom finished
concrete). 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 levelling
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 temperatures must be between 55º and 95ºF. Suitable substrates include concrete, plywood, cork,
particle or chip board, stone, ceramic, terrazzo, Warmboard®, 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
TROWEL NOTCH REQUIREMENTS (Spread rates are approximate):
Replace as needed to achieve proper spread rate.
Description Use Size Coverage Rate
Bona 1250G Trowel or
1250G Clip-on Trowel
Engineered flooring up to
8” width or solid plank
3/4” thick and 5” width
1/4” x 1/4” x 7/16” Vnotch 55-60 sq. ft./gallon
Bona 1500G Trowel
Engineered flooring up to
16” width or solid plank
3/4” thick and 9” width
5/16” x 5/16” x 7/16”
V-notch 50-55 sq. ft./gallon
Bona MBP Clip-On Trowel
Moisture barrier
protection for Engineered
flooring up to 16” width or
solid plank 3/4” thick and
9” width
7/16” V-notch with
MBP spacer 30-35 sq. ft./gallon
Bona Engineered
Flooring Trowel (EF)
Engineered flooring,
maximum 3/4” thick and
7” width
7/32” x 13/64”x
25/64”V-notch
70-75 sq. ft./gallon
for adhesion only
SPREADING ADHESIVE AND LAYING FLOORING: Spread adhesive on the substrate while holding the
Bona trowel at a 90º angle, using a smooth semicircular motion. Do not leave any puddles of adhesive. Set
the flooring into adhesive while the adhesive is still wet. 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.
Bona R851
Technical Data Sheet
Rev 07/12/2019
This data sheet replaces all previous versions page 3/3
Adhesives
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. Keep from freezing. Do not store for extended
periods in excess of 90ºF.
Item# Size #/Case Lbs./Case
BR85106100USBO 3 Gallons 1 38.6
