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A lot goes into tackling a concrete repair or project. Unlike a carpentry project, you can’t just grab a stack of lumber and get to work. You have to wait for the right weather conditions, select the right cement mix, use the proper ratio, and work fast enough that the concrete doesn’t begin to set before you’re ready. You want to mix it right the first time to make sure it adheres properly.
To help avoid an unfortunate scenario, use the best concrete bonding agent. Whether mixing the agent with a slurry or using an agent to bond two concrete surfaces together, a high-quality product can get the job done. This guide will help you choose the best concrete bonding agent for your project.
- BEST OVERALL: Quikrete 1 Gal. Concrete Bonding Adhesive
- BEST BANG FOR THE BUCK: Quikrete 1 Qt. Acrylic Fortifier
- BEST FOR COLD TEMPERATURES: SikaLatex 1 Gal. Concrete Bonding Adhesive
- BEST FOR CONCRETE BLOCKS: Liquid Nails – LN-905 Landscape Block Adhesive
- BEST POLYURETHANE: Loctite PL Premium Polyurethane Construction Adhesive
Features to Look for in the Best Concrete Bonding Agent
Before choosing the best concrete bonding agent for your project, be aware of a few factors. Learn how to use the agent, how to condition the surface, and how to determine if the agent will provide waterproofing. Read more about these factors next.
Instructions
To avoid completing the same project twice, be sure to follow the directions listed on the concrete agent’s packaging. More than any other factor, using the product in the exact manner that the manufacturer recommends is the best way to achieve the best results.
Bonding agents often can be used in different ways. They can cover an existing surface or mix directly into the concrete mix. Other products require two or three different chemicals to activate properly.
Surface Contaminants
Typically, the product won’t matter if the surface is dirty, dusty, or corroding. For any material to bond to a surface in this type of condition, it must be prepared. The best way to clean the surface is to use a mild detergent and water, though a power washer might speed up the process. To remove some surface grittiness or flaking paint, use a handheld wire brush.
Once the surface is clean, keep down the dust. Mix the concrete away from the surface to avoid dust or mud from splashing up and causing adhesion issues.
Waterproof Ability
While it takes water to turn cement into concrete, water can be concrete’s worst enemy. If water makes its way into the concrete surface and freezes, it can split an otherwise perfect surface with ease. It can even pop a brand-new patch right off your concrete surface.
Water can do the same thing to a glue or polyurethane compound, though their flexibility makes them a little more resistant to cracking.
Using a waterproof bonding agent helps thwart the negative effects of water on a project. Check that the product provides a waterproof surface before using it in an outdoor setting.
Our Top Picks
Now that you know what to look for in the best concrete bonding agents, start comparing the top products. A list of some of the best concrete bonding agents on the market follows.
Best Overall
Quikrete 1 Gal. Concrete Bonding Adhesive
For a concrete bonding agent that can help create a first-rate finished product on a range of different concrete projects, check out Quikrete’s 1 Gal. Concrete Bonding Adhesive. Use this product as a paint-on adhesive, coating the base surfaces with a sprayer, roller, or brush before applying a fresh coat of concrete. Alternatively, mix it with a slurry in place of water, using two parts cement to one part bonding agent.
One of the best features of this agent is that it doesn’t require the user to roughen the surface before applying. While other products might require laborious scuffing with a wire brush, the adhesive will cling to smooth surfaces, provided they’re free of dirt and contaminants.
Best Bang For the Buck
Quikrete 1 Qt. Acrylic Fortifier
Repairing cracks, chips, and missing chunks from the edge of a concrete surface can be a messy proposition unless you use time-consuming forms to hold the slurry in place. To save time and money on the next repair, consider this 1 Qt. Acrylic Fortifier by Quikrete.
The agent mixes in with the cement mixture in place of water. It promotes adhesion with the existing concrete while also stiffening the concrete mix, so it holds in place without sliding off the pad.
This fortifier makes the concrete mix begin to harden within five minutes, so be sure to mix only as much as you can use in that time frame.
Best For Cold Temperatures
SikaLatex 1 Gal. Concrete Bonding Adhesive
If cold temperatures threaten to wreak havoc on your concrete repair, consider Concrete Bonding Adhesive by SikaLatex. Brush, roll, or spray it on the existing concrete surface, or use it as a water replacement in a concrete or mortar slurry. Alternatively, use it in a grout mixture—a particularly attractive option for tile floors in unheated mudrooms.
While it works as a fortifier and bonding agent, the acrylic polymers increase the repair job’s resistance to freeze-and-thaw cycles, allowing the patch to last longer. If used as a repair slurry, coat the area and immediately apply a finish coat, speeding up the repair time considerably.
Best For Concrete Blocks
Liquid Nails – LN-905 Landscape Block Adhesive
Block walls have lots of places where water can sneak in and cause serious issues. Liquid Nails LN-905 Landscape Block Adhesive creates a weatherproof bond that resists water’s effects, resulting in a long-lasting concrete wall, garden bed, or masonry project.
The LN-905 mixture comes in 10-ounce tubes that you can install in a standard caulking gun, allowing you to apply just the right amount without messy cement bags, buckets, and mixing. Simply squeeze the appropriate amount on the base course of blocks and set the new course on top. Use it to build new walls or repair old ones, and it works with concrete, stone, and brick materials.
Best Polyurethane
Loctite PL Premium Polyurethane Construction Adhesive
Sometimes all it takes to get the job done is a classic. If you prefer the age-old approach for the repairs, check out Loctite’s PL Premium Polyurethane Construction Adhesive. This adhesive comes in a small 4-ounce squeeze tube, a large 28-ounce cartridge, and a standard 10-ounce tube cartridge that’s designed to fit most caulking guns.
PL Premium can create a bond between almost any two materials that are in almost any condition. It can bond with wet or frozen surfaces and will cure even in cold temperatures. Its polyurethane base makes it waterproof and weather-resistant, so it can tackle outdoor concrete projects and repairs.
FAQs About Concrete Bonding Agents
Bonding concrete isn’t necessarily rocket science, but masonry can be a little mysterious. If you still have some questions about the best concrete bonding agents, you’re not alone. This section features a collection of the most commonly asked questions about bonding concrete. See if you can find the answer to your question below.
Q. What is the best way to bond concrete to concrete?
It depends on the project. If it’s a pad or slab repair, mixing concrete with a bonding agent allows you to work quickly and form the repair to the pad. If you simply want to stick a block to another block, a polyurethane-based construction adhesive will do the job.
Q. What is bonding cement used for?
The most common use for bonding cement is to build block walls without mortar joints, but you can use it to bond two other concrete surfaces as well.
Q. Is surface bonding cement waterproof?
Surface bonding cement is waterproof. It consists of Portland cement, fine aggregates, and fibers, which combine to create a waterproof surface when cured.