- Over 25 years of industryleading performance
- Moisture vapor protection
- Bostik's Blockade TM antimicrobial protection
Bostik's BEST® is a high performance adhesive and moisture control membrane. Its superior properties provide a tough, flexible, tenacious bond to a variety of surfaces. Bostik's BEST ® high tacking formula exhibits exceptional green grab immediately after troweling, making installation easier and more secure. This adhesive has low VOC's (as calculated per SCAQMD Rule 1168) and does NOT contain any water. Bostik's BEST® contains Bostik's BLOCKADE TM antimicrobial protection, which inhibits the growth of bacteria, mold, or mildew on the surface of the dried adhesive.
Bostik's BEST® has low moisture vapor permeability and is not adversely affected by moisture vapor. As a result, it will reduce moisture vapor transmission through the concrete. When applied as directed as a moisture vapor membrane, it will prevent damages caused by subfloor moisture beneath dimensionally stable, engineered wood flooring only. Bostik's BEST ® may be used for concrete slabs with elevated moisture levels up to 12 lbs. per 1,000 square feet per 24 hours (using an anhydrous calcium chloride test kit according to ASTM F-1869 test method), and up to 82% RH (tested in accordance with ASTM F-2170). For substrates that have an MVER of greater than 12 lbs or > 82% RH, use Bostik's MVP4 TM prior to the application of Bostik's BEST® for unlimited moisture vapor protection, or use Bostik's Ultra-Set® SingleStep2 TM or GreenForceT.
Bostik's BEST®'s elastomeric characteristics establish an antifracture membrane that can bridge cracks up to 1/8" (3mm) which can occur in the substrate prior to or after installation. This superior elasticity allows the adhesive to move with the wood as it expands and contracts with changes in humidity and temperature over the life of the floor.
Bostik's BEST® may be used to adhere all engineered, solid (adhesive only), bamboo (adhesive only), cork, and parquet hardwood flooring (adhesive only) . Bostik's BEST® may be used over all properly prepared substrates common to hardwood flooring installations including concrete, plywood, OSB, particle board (underlayment grade, above grade applications), well bonded vinyl/VCT and ceramic tile, cement backer board, gypsum underlayments (dry, above-grade), cement patch/ underlayments, radiant-heat flooring, and properly prepared terrazzo. This adhesive can also be used to install plywood as described below, as well as ceramic tile, marble, and stone inlays for light commercial and/or residential applications.
Bostik's Best®'s low-VOC formulation (as calculated per SCAQMD Rule 1168) may contribute toward LEED® credits under section EQ 4.1: Low-Emitting Materials - Adhesives & Sealants.
Read and understand data sheet completely before beginning installation. Follow industry standards and flooring manufacturer's recommendations for acclimation, design, layout, and application of wood flooring material. If jobsite conditions are outside of flooring manufacturer's recommendations, take necessary corrective actions. Whether the moisture content of substrate exceeds or is within the flooring manufacturer's recommendations, to address current or possible future subfloor moisture, sound, and cracks (up to 1/8"), apply Bostik's BEST® as directed.
Surfaces must be absorptive, clean, and free from loose materials, oil, grease, sealers, curing compounds, waxes, silicates, laitance, and all other surface contaminants that may inhibit proper bond. Completely remove cutback adhesive residue or other surface contaminants by diamond grinding, shot blasting, or scarifying to open the pores of the concrete. All surfaces to be treated must have a concrete surface profile (CSP) of 1-3 (similar to a broomed finish), as defined by ICRI (International Concrete Repair Institute, Guideline No. 03732). Maximum acceptable floor variation is 3/16" in 10 feet. Areas requiring patching or leveling must be done using a Portland cement-based material (e.g., Bostiks UltraFinishT, Webcrete® 95, Webcrete® 98 or SL-150 TM Self-Leveling Underlayment). Seal any cracks larger than 1/8" or expansion joints with Bostik 915FS TM or 955-SL TM .
PLEASE NOTE: Concrete substrate should NO TM be smooth and reflective; it must have a concrete surface profile of CSP 1-3 (similar to a broomed finish), as define by ICRI (International Concrete Repair Institute, Guideline No. 03732). It is advisable to test for adequate substrate absorption and texture in several areas throughout the jobsite by sprinkling droplets of water onto the slab. The drops of water should show signs of penetrating the substrate within one minute. This is evidenced by a water stain on the concrete without a "domed" droplet. If no signs of water penetration are shown within one minute and "domed" droplets remain (similar to drops on a car hood) the substrate will need to be mechanically textured.
The installation begins with a starter row secured to the subfloor; the starter row provides a stationary point to push against so flooring doesn't move during installation. Once the starter row is secured, apply adhesive/membrane to substrate using the appropriate trowel. See the chart on last page for proper trowel selection. Flooring may be installed using a "Wet-Lay" method of installation. For "Wet-Lay" installations, spread the adhesive and begin to install the flooring immediately. Periodically lift boards immediately after installation to ensure proper slab coverage and transfer to the back of the flooring. As you work, immediately clean any adhesive from prefinished flooring with Bostik's
Ultimate TM Adhesive Remover or mineral spirits (be careful not to harm finish), then dry buff with a non-abrasive towel.
After a few rows have been installed, and as you move across the room, tape the boards together using removable 3M #2080 Blue tape to prevent boards from sliding and to secure close-fitting joints. Rolling is recommended for all installations. Flooring that is not flat should be tacked, weighted, or rolled to ensure proper contact between the flooring and substrate.
PLYWOOD OVER CONCRETE: Score 4' x 4' or 2' x 8' sheets of 3/4" exterior-grade plywood on the backside every 8" to 10" by using a circular saw and cutting one-half the thickness of the plywood; "scoring or kerfing" takes the tension out of the plywood and helps to prevent possible warping or curling. Apply adhesive/ membrane to substrate and then set plywood into the wet adhesive/membrane. Allow the adhesive/membrane to fully cure before nailing or using Bostik's BEST® adhesive/membrane to install flooring. If nailing to the plywood, nails must not protrude through to the adhesive/membrane.
As you work, immediately clean any adhesive from prefinished flooring with Bostik's Ultimate TM Adhesive Remover or mineral spirits (be careful not to harm finish), then dry buff with a nonabrasive towel. Immediately clean all tools and equipment with Bostik's UltimateT Adhesive Remover or mineral spirits before material cures.
TROWEL CLEAN-UP TIP: Before use, cover areas of the trowel that are not used to spread the adhesive with blue tape. After use, simply tear off tape before material cures, and clean the remainder of the trowel with adhesive remover.
Store at temperatures between 50°F and 100°F (10°C and 38°C). Shelf life is one year from date of manufacture in closed, original packaging.
Re-Seal Partially Used Container: With pail upright place a sheet of plastic (e.g., trash bag) over the top of the pail. Secure lid tightly over the plastic on top of pail. Carefully turn pail upside down. Plastic will help prevent the material from bonding the lid closed. Re-Open Partially Used Container: Carefully turn pail right side up. Remove lid. Carefully cut and discard cured material and plastic from top of pail. Any uncured material may be used.
- Periodically check coverage of adhesive during installation; 100% substrate coverage and adhesive transfer to the back of the flooring is required to protect against damages from subfloor moisture.
- Due to limitations with solid and bamboo wood flooring (e.g., lack of dimensional stability), "below-grade" installations are limited to engineered hardwood flooring.
- For substrates with any history of moisture problems, or for concrete slabs exceeding 12 lb MVER or 82% RH, use a high performance moisture vapor reduction product such as Bostik's MVP4T prior to the application of Bostik's BEST®, or use Bostik's Ultra-Set® SingleStep2T or GreenForceT.
- Do not use in areas subject to hydrostatic head.
- Do not install solid wood flooring over VCT/vinyl.
- Bamboo installations should follow solid hardwood flooring installation recommendations.
- Slab temperature should be between 50°F and 95°F (10°C and 35°C) during installation.
Available in 5 gallon pails (36 pails/pallet),
2 gallon pails (96 pails/pallet),
10.1 oz cartridges (24 cartridges/case, 105 cases/pallet), and
28 oz cartridges (12 cartridges/case, 60 cases/pallet).
Note: This chart is for reference only; actual jobsite times may vary.
* Dry, above grade
* 2 Residential or light commercial only
* 3 Humidity affects cure to a greater degree than temperature; the higher the humidity, the faster the cure. Under normal conditions, light foot traffic is acceptable after 6 to 8 hours; normal traffic after 12-16 hours.
* 4 Per ASTM E-96 Standard Test Methods for Water Vapor Transmission of materials. Ratings are g/m2-24 hour-mmHG.
* 5 Please refer to the Open/Working Time Chart.
* 6 Per ASTM E203-01 Standard Test Method for water using Volumetric Karl Fischer Titration Method. Results rounded to the nearest tenth. Test Method has error range of +/- 0.2%.
In order to form a membrane that functions properly for moisture vapor protection, the right trowel needs to be selected to achieve both 100% coverage of the substrate and 100% transfer to the back of the flooring. Jobsite conditions, profile of the substrate, depth of back channeling in the flooring, and other factors affect the amount of adhesive that must be applied to achieve proper coverage and transfer. Always pull a board at the beginning of and during the installation process to confirm adequate coverage and transfer. Trowel size may need to be changed to achieve the required coverage and transfer. See trowel suggestions below.
ADHESIVE & MOISTURE MEMBRANE INSTALLATION METHOD
Suggested Trowel (For use as an adhesive only, refer to adhesive only installation method.)
Engineered wood flooring up to 5/8" thick.
Engineered wood flooring >5/8" thick, or plywood.
Trowel size is suggested to maximize coverage of adhesive. Periodically lift a board to ensure the following conditions are being met: 100% coverage of concrete substrate and 100% transfer to the back of the flooring product. Uneven subflooring may require the use of either a leveling/patching material, or a larger V-notched trowel for proper coverage of adhesive.
Trowel size is suggested to maximize coverage of adhesive. Periodically check coverage of adhesive during installation: >80% coverage and transfer to the back of the flooring is required for all engineered wood flooring; >95% coverage and transfer is required for all solid wood flooring or bamboo flooring products.
COMBUSTIBLE. HARMFUL IF SWALLOWED OR INHALED. CONTAINS POTENTIAL SENSITIZER. MAY CAUSE ALLERGIC SKIN OR LUNG REACTION. MAY IRRITATE EYES, SKIN AND RESPIRATORY TRACT. Do not breathe fumes. Do not get in eyes, on skin or on clothing. Do not swallow. Use only in a well-ventilated area or wear mask. Keep away from flames or sparks. Wash thoroughly after handling. Store container in a cool (60-80°F / 15°-30°C), dry area with lid tightly sealed. Do not reuse container.
Limited Warranty found at www.bostik-us.com or call 800.726.7845. TO THE MAXIMUM EXTENT ALLOWED BY LAW, BOSTIK DISCLAIMS ALL OTHER EXPRESS OR IMPLIED WARRANTIES, INCLUDING WITHOUT LIMITATION WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. UNLESS OTHERWISE STATED IN THE LIMITED WARRANTY, THE SOLE REMEDY FOR BREACH OF WARRANTY IS REPLACEMENT OF THE PRODUCT OR REFUND OF THE BUYER'S PURCHASE PRICE. BOSTIK DISCLAIMS ANY LIABILITY FOR DIRECT, INCIDENTAL, CONSEQUENTIAL, OR SPECIAL DAMAGES TO THE MAXIMUM EXTENT ALLOWED BY LAW. DISCLAIMERS OF IMPLIED WARRANTIES MAY NOT BE APPLICABLE TO CERTAIN CLASSES
OF BUYERS AND SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF INCIDENTAL OR CONSEQUENTIAL DAMAGES, SO THE ABOVE LIMITATIONS MAY NOT APPLY TO YOU. It is the buyer's obligation to test the suitability of the product for an intended use prior to using it. The Limited Warranty extends only to the original purchaser and is not transferable or assignable. Any claim for a defective product must be filed within 30 days of discovery of a problem, and must be submitted with written proof of purchase.
This document supersedes all previously published literature.