Bostik Best vs MultiGrip: Which Adhesive Reigns Supreme for Your Floors?
You’ve selected the perfect hardwood, visualized the layout, and are ready to begin one of the most transformative projects in your home. But a critical, often overlooked decision stands between you and a lifetime of beautiful, stable flooring: choosing the right adhesive. This single choice can mean the difference between a flawless, permanent installation and a floor plagued by squeaks, gaps, or catastrophic failure.
For decades, professionals and savvy DIYers have trusted Bostik for hardwood flooring installations. Two of their most popular urethane adhesives, Bostik’s BEST® and Bostik MultiGrip™, consistently come up in the debate. While both offer tenacious bonds, they are engineered for different challenges, leaving many to wonder which is the right choice for their specific project.
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Why Your Hardwood Flooring Adhesive Choice is Mission-Critical
Choosing a hardwood flooring adhesive isn’t merely about sticking wood to a subfloor; it’s about creating a unified flooring system that can withstand decades of use and environmental changes. A premium urethane adhesive serves multiple functions that are vital to the longevity of your investment. It must be strong enough to prevent boards from shifting but flexible enough to allow for the natural expansion and contraction of wood through seasonal humidity changes.
Furthermore, the right adhesive acts as a crucial line of defense against subfloor issues. Many installations, especially over concrete slabs, face the persistent threat of moisture vapor transmission, which can cause wood to cup, warp, and buckle. A top-tier adhesive with an integrated moisture barrier can prevent this, saving you from devastating and costly repairs down the road.
Meet the Contenders: An Overview of Bostik’s Urethane Adhesives
Bostik has built its reputation on providing reliable and innovative installation solutions. Both BEST® and MultiGrip™ are one-part, moisture-cure urethane adhesives, meaning they are ready to use out of the pail and cure by reacting with ambient moisture. This chemistry creates a tough, yet elastic, bond that is highly resistant to water once cured.
Bostik’s BEST®: The High-Performance Champion
For over 25 years, Bostik’s BEST® has been an industry benchmark for high-performance wood flooring adhesive. It is renowned for its powerful bond, exceptional green grab (the initial tackiness that holds boards in place), and, most importantly, its built-in moisture vapor control membrane. This adhesive is engineered for the most demanding installations, including solid hardwood, wide planks, and exotic species that are more sensitive to changes in humidity.
Its formulation provides a tough, flexible, and tenacious bond to a vast array of substrates, from concrete and plywood to well-bonded vinyl and ceramic tile. The elastomeric properties of BEST® also create an anti-fracture membrane that can bridge minor cracks in the subfloor, adding another layer of protection for your finished floor.
Bostik MultiGrip™: The Versatile All-Rounder
Bostik MultiGrip™ is another powerful urethane adhesive designed as a versatile and reliable option for a wide range of applications. Like its premium counterpart, MultiGrip offers a tough, flexible bond that moves with the wood throughout its life, preventing stress-related failures. It is often praised for its easy-to-trowel consistency, which can speed up the installation process.
While also providing moisture protection, MultiGrip is typically positioned for installations where subfloor moisture is within a more moderate range. It is an excellent choice for engineered hardwood, parquet, and certain solid wood installations over approved substrates, offering a balance of performance and value.
Head-to-Head Comparison: Bostik Best vs MultiGrip
Understanding the nuanced differences between these two products is key to making the right decision. While both are excellent adhesives, their strengths are tailored to different scenarios. The choice often comes down to the type of wood being installed, the nature of the subfloor, and the level of performance assurance you require.
The Ultimate Showdown: A Detailed Feature Comparison
To clarify the decision-making process, let’s break down the core features of each adhesive in a side-by-side comparison.
| Feature | Bostik’s BEST® | Bostik MultiGrip™ |
|---|---|---|
| Primary Use Case | High-performance applications; solid & engineered wood, wide planks, high moisture concerns. | General purpose; engineered wood, parquet, some solid wood, moderate moisture concerns. |
| Moisture Protection | Superior moisture vapor barrier. No testing needed for engineered wood on dry, cured slabs. | Good moisture protection up to 6 lbs MVER or 80% RH. |
| Elastomeric Properties | High elasticity; provides an anti-fracture membrane that bridges cracks up to 1/8″. | Excellent elastomeric properties allow for natural wood movement. |
| Workability | Exceptional green grab and high tacking formula holds boards firmly during installation. | Easy-to-trowel consistency with a long open time, simplifying the installation process. |
| Sound Dampening | Provides inherent sound dampening properties. | Offers sound dampening benefits. |
| Antimicrobial Protection | Contains Bostik’s BLOCKADE™ to inhibit mold and mildew growth on the dried adhesive. | Contains Bostik’s BLOCKADE™ for antimicrobial protection. |
| VOC Content | Low VOC formulation. | Low VOC formulation. |
Moisture Control: The Unseen Battle Under Your Feet
The single greatest threat to a hardwood floor is moisture. Whether it’s a concrete slab that isn’t fully cured or seasonal moisture wicking up from the ground, water vapor can be devastating. This is where Bostik’s BEST® truly shines. Its formulation provides such robust moisture protection that for engineered hardwood installations over a properly prepared and cured concrete slab, costly and time-consuming moisture testing is not required.
MultiGrip also offers good moisture protection, capable of handling moisture vapor emission rates (MVER) up to 6 lbs per 1,000 sq. ft. over 24 hours. This is perfectly adequate for many situations, particularly over plywood subfloors or on-grade slabs in arid climates. However, for below-grade installations or in any scenario where moisture is a significant concern, the superior protection of BEST® provides invaluable peace of mind.
Application and Workability: A Pro’s Perspective
Both adhesives are designed for professional use, but they offer slightly different experiences during application. Installers often praise MultiGrip for its smooth, easy-to-spread consistency. Its long open time means you can trowel out a larger area of adhesive before it begins to skin over, which can make the installation process faster and less stressful.
On the other hand, Bostik’s BEST® is known for its incredible “green grab.” This immediate, high-tack bond is a lifesaver when installing wide, heavy planks or working on vertical surfaces, as it prevents the boards from slipping out of place. While it may be slightly stiffer to trowel than MultiGrip, this tackiness is a feature that many professionals rely on for precision installations.
Real-World Scenarios: Which Adhesive Should You Choose?
Theory is helpful, but the best way to choose is to apply these features to practical, real-world situations. Let’s explore a few common installation scenarios.
Scenario 1: Installing 7-inch Solid White Oak on a Concrete Slab
In this case, the choice is clear: Bostik’s BEST®. Solid wood is more susceptible to dimensional changes from humidity than engineered wood, and wide planks exert significantly more stress on the adhesive bond. Couple that with a concrete subfloor—a potential source of moisture—and you need the absolute best protection available. The superior moisture barrier and anti-fracture capabilities of BEST® are essential for ensuring a successful, long-term installation.
Scenario 2: Installing 5-inch Engineered Hickory Over a Plywood Subfloor
For this project, Bostik MultiGrip™ is an excellent and cost-effective choice. Engineered flooring is inherently more stable than solid wood, and a plywood subfloor (on an upper level of a home) presents a much lower moisture risk than a concrete slab. MultiGrip provides more than enough bonding strength and moisture resistance for this application, and its easy-to-trowel nature will make the job go smoothly.
Scenario 3: A Budget-Conscious DIY Renovation with Engineered Flooring
If you are working on a tight budget, MultiGrip™ offers fantastic value without compromising on the core security of a urethane bond. However, it’s crucial not to cut corners on subfloor preparation. Even with a more budget-friendly adhesive, you must ensure your subfloor is clean, flat, and dry. An inexpensive moisture test kit is a wise investment to confirm that the subfloor’s moisture levels are within the acceptable range for MultiGrip.
Pro Tips for a Flawless Urethane Adhesive Installation
Regardless of which Bostik adhesive you choose, proper technique is paramount to success. Urethane adhesives are famously unforgiving once cured, so careful and clean work is essential.
- Subfloor Prep is King: Your subfloor must be structurally sound, clean, dry, and flat. Scrape or grind away any old adhesive, paint, or contaminants that could interfere with the bond.
- Acclimatize Everything: Both your hardwood flooring and the adhesive should be acclimated to the home’s normal living conditions (temperature and humidity) for at least 72 hours before installation.
- Use the Right Trowel: The trowel’s notch size is critical. It determines how much adhesive is applied, which directly impacts both the bond strength and the integrity of the moisture barrier. Always follow the specific trowel recommendations on the adhesive’s technical data sheet for the type of flooring you are installing.
- Clean As You Go: This cannot be overstated. Keep a supply of mineral spirits or recommended adhesive remover wipes on hand. Carefully clean any adhesive that gets on the surface of prefinished boards immediately. Once cured, urethane is incredibly difficult to remove without damaging the floor’s finish.
- Ensure Complete Coverage: When spreading the adhesive, your goal is to achieve 100% contact between the adhesive, the subfloor, and the back of the flooring plank. This ensures a solid bond and a continuous moisture barrier.
Proper installation goes beyond just the floor itself. During a renovation, you might notice other areas that need attention. For instance, ensuring a tight seal in wet areas is crucial; if you see gaps, knowing how to properly replace rubber seal around shower glass can prevent future water damage. Similarly, if you encounter different flooring types meeting, you’ll want to how to fill gap between tile and wood floor for a seamless and professional look. Finally, always prioritize safety. If you see unsafe wiring, understanding how to cover exposed romex is a non-negotiable step to protect your home and family.
The Final Verdict: Is Bostik’s BEST® Always the Best Choice?
So, which adhesive wins the showdown? The truth is, there is no single winner for every project. The “best” choice is the one that is best suited to your specific needs.
Bostik’s BEST® is the undisputed champion of high-performance and high-risk installations. If you are installing expensive solid hardwood, wide planks, or are working over a concrete slab with any moisture uncertainty, the premium cost of BEST® is an inexpensive insurance policy against floor failure. It provides the highest level of moisture protection and bond strength in the Bostik lineup, offering maximum peace of mind.
Bostik MultiGrip™ is the reliable and versatile workhorse. For the vast majority of common installations, such as engineered hardwood over plywood, it delivers a powerful, permanent bond with adequate moisture protection at a more accessible price point. Its user-friendly application makes it a favorite for installers working on straightforward projects where extreme moisture is not the primary concern.
Ultimately, by evaluating your flooring type, subfloor conditions, and project budget, you can confidently select the right Bostik adhesive to ensure your beautiful new hardwood floor remains a source of pride and value for decades to come.
