Selecting the proper adhesive is crucial for robust, long-lasting brickwork. With so many options available, it can be challenging to determine which product is best suited for your specific application.
Brick Adhesives
Brick adhesives, also known as masonry adhesives or mortars, are specially formulated to bond bricks together as well as to other masonry materials. They cure to form a strong, rigid bond that holds bricks in place. The main types of brick adhesives include:
- Cement-based mortar – A mixture of cement, lime, sand, and water. Traditionally used for bricklaying. Provides high compressive strength but lower flexibility.
- Masonry adhesive – Heavy-duty construction adhesive designed for structural bonding of masonry materials. Offer excellent adhesion and flexibility.
- Epoxy adhesive – Two-part adhesive that creates a durable, waterproof bond. Superior strength but requires precise mixing.
- Polyurethane adhesive – Single component, moisture-curing adhesive. High elasticity and water resistance.
- Acrylic latex adhesive – Water-based adhesive composed of acrylic polymers. Easy to apply but less strong than other adhesives.
The right adhesive for your project depends on the specific application, types of materials, and exposure conditions. Key factors to consider include bond strength, flexibility, water and weather resistance, drying time, and cost.
Brick to Brick Adhesives
Adhering bricks to other bricks requires an adhesive that can withstand the stresses and loads transmitted across the brickwork. For structural integrity, the brick-to-brick bond must be strong, durable, and flexible.
Epoxy Adhesives
Epoxy is one of the most heavy-duty adhesives available for structural brick bonding. It is composed of two parts – an epoxy resin and a polyamine hardener – that react when mixed to form an exceptionally strong cross-linked bond.
Key benefits of epoxy brick adhesives:
- Superior bond strength – Strongest adhesive for bricks. Capable of bonding bricks with over 2,000 PSI tensile strength.
- Waterproof – Cured epoxy resists water, moisture, and chemical exposure. Suitable for underwater and submerged applications.
- Durable – Maintains strength and adhesion for many years. Resistant to extreme temperatures, vibrations, and stress.
- Versatile – Can bond to concrete, stone, metals, glass, and many plastics besides brick.
- Rigid bond – Provides excellent load transfer between bricks.
Popular epoxy adhesives for brickwork include PC Products PC-Rotfix Resin Adhesive, Loctite Epoxy Heavy Duty, and Gorilla 2 Part Epoxy. Always follow precise mixing directions when using epoxy.
Polymer-Modified Mortars
Polymer-modified mortars provide an alternative to epoxy for bonding bricks. These contain polymers such as latex or rubber mixed into cement mortar to improve flexibility, adhesion, and water resistance compared to standard cement mortar.
Advantages of polymer-modified mortars:
- Enhanced flexibility – Ability to flex minimizes cracking and failure.
- Stronger bond – Polymers increase bond strength to brick surfaces.
- Easier workability – More flexible and adhesive than standard mortar. Requires less re-tooling of joints.
- Weather resistance – Polymers improve resistance to water and climate exposure.
- Lower cost – More affordable than epoxy.
Popular options include Quikrete Polymer Modified Mortar, Specco Polymer Modified Masonry Mortar, and Mortar Net Polymer Modified Mortar Additive.
Waterproof Brick Adhesives
For bricks exposed to water, moisture, or weathering, a waterproof adhesive is essential. Water can degrade cement-based mortars and reduce bond strength over time.
Polyurethane Construction Adhesives
Polyurethane formulas create flexible, waterproof, and chemically resistant bonds. As a one-part adhesive, polyurethane is also easier to apply than epoxy.
Benefits of polyurethane brick adhesives:
- Waterproof – Cured polyurethane is highly water resistant. Prevents water damage to bricks.
- Strong adhesion – Bonds well to porous masonry materials. Typically over 800 PSI tensile strength.
- Flexible – Ability to expand and contract minimizes cracking.
- Weather/UV resistant – Does not degrade from sun, rain, snow, or temperature fluctuations.
- Versatile – Bonds brick, concrete, stone, wood, foam, plastics, and more.
Top polyurethane adhesives include Loctite PL Premium Construction Adhesive, Gorilla Heavy Duty Construction Adhesive, and SikaFlex Construction Adhesive.
Silicone Sealants
Silicone sealants provide maximum water repellency while remaining flexible to accommodate expansion and contraction. Best for filling gaps and sealing bricks rather than load-bearing adhesion.
Advantages of silicone brick sealants:
- Extremely water repellent – Silicone chemistry makes it highly waterproof.
- Long-lasting flexibility – Remains elastic for decades. Will not turn brittle or crack over time.
- UV/weather resistant – Excellent for outdoor brickwork.
- Low-VOC – Environmentally friendly formulas available.
- Range of strengths – Options for structural glazing as well as sealing.
Good silicone sealant choices include GE Silicone II, Loctite Clear Silicone, and NP1 clear silicone.
Best Overall Adhesive for Bricks
For a versatile adhesive suitable for most indoor and outdoor brick bonding applications, Gorilla Heavy Duty Construction Adhesive stands out as a top choice.
Here’s why Gorilla Construction Adhesive excels as an all-purpose brick adhesive:
- Strong adhesive power – Bonds most materials including brick, concrete, stone, metals, wood, more.
- Weatherproof & water resistant – Ideal for exterior applications. Prevents moisture damage.
- Durable long-term strength – Holds strong for years without cracking or losing adhesion.
- Flexible bond – Allows for minor expansion and contraction.
- Easy to dispense – Anti-clog nozzle prevents messes.
- Versatile uses – Suitable for vertical and overhead applications.
Gorilla Construction Adhesive is suitable for interior and exterior bricks in residential or commercial projects. It strikes an optimal balance of strength, flexibility, and water resistance.
Heavy Duty Adhesives for Structural Brickwork
For structural brickwork applications that bear heavy loads, such as retaining walls, foundations, and multi-story buildings, a high-strength adhesive is necessary to achieve structural integrity. The adhesive must maintain a rigid, secure bond under significant stresses.
Epoxy Adhesives
Epoxy continues to be the gold standard for bonding bricks in heavy duty structural applications. The exceptional compressive and tensile strength of epoxy creates a super-strong cross-linked bond between bricks.
For structural applications, consider extra-strength epoxy adhesives like:
- J-B Weld Steel Reinforced Epoxy – Formulated to bond steel and other materials in high strength repairs.
- PC Products PC-7 – Heavily loaded epoxy anchoring adhesive. Offers over 4,000 PSI tensile strength.
- Loctite Epoxy Extra Time – Provides extended working time for large jobs.
Always follow precise mixing and curing instructions when using epoxy for structural applications.
Polyester Resin Adhesives
Polyester resin adhesives offer an alternative to epoxy for structural bonding of bricks. Polyester resin forms an incredibly strong bond and offers rapid cure times.
Advantages of polyester resin adhesives:
- Fast curing – Reaches handling strength in about 1 hour. Speeds up repairs.
- High early bond strength – Achieves strong adhesion quickly.
- Minimal shrinkage – Prevents cracking and failure as it cures.
- Strong rigid bond – Excellent for transferring loads between bricks.
Quality polyester resin brick adhesives include Plexus MA310 and Bond Fast Super Glue by Resinlab. Use caution when handling polyester resin, as the fumes can be hazardous prior to curing.
Outdoor Brick Adhesives
For outdoor brickwork, selecting an exterior-grade adhesive is crucial to withstand weathering and prevent moisture damage. Outdoor brick adhesives must maintain strong, flexible, waterproof bonds despite exposure to rain, humidity, sunlight, extreme temperatures, and freeze-thaw cycles.
Polyurethane Construction Adhesives
Polyurethane formulas offer ideal performance for exterior brickwork. As discussed earlier, polyurethane adhesives form weatherproof, UV/moisture-resistant bonds. Leading brands like Loctite PL Premium, Gorilla Construction Adhesive, and SikaFlex resist outdoor conditions for years.
Before application, surfaces should be clean and dry. Follow any manufacturer precautions for low temperature use.
Silicone Sealants
Silicone makes an excellent choice for sealing outdoor brickwork. It remains permanently flexible and waterproof after curing, unlike stiffer adhesives that can crack. Silicone can expand and contract with the bricks as temperatures fluctuate.
Use silicone sealant to seal gaps, joints, or cavities in outdoor brickwork. Top silicone sealant choices like GE Silicone II and Loctite Clear Silicone withstand sun, rain, and freezing without losing flexibility or adhesion.
Adhesives for Bonding Bricks to Concrete
Attaching brick veneers, walkways, and steps to concrete foundations and slabs is a common application. The adhesive must bond dissimilar materials while allowing for differential movement between the brick and concrete.
Hybrid Polymer Adhesives
Hybrid polymer adhesives combine polymers like polyurethane and silicone to achieve maximum adhesion between bricks and concrete. The flexible silicone component accommodates expansion and contraction, while the polyurethane provides strong structural bonding power.
Leading hybrid polymer brick adhesives include:
- Loctite PL500 Landscape Block Adhesive – Designed for bonding retaining wall blocks, pavers, and stones to concrete. Withstands outdoor exposure.
- SikaBond AT Metal & Concrete Adhesive – Extremely strong dual-component hybrid. Bonds brick, metals, concrete, wood, and more.
- Liquid Nails Fuze*It All Surface Adhesive – All-purpose hybrid adhesive and sealant. Water and weather resistant.
Epoxy Adhesives
For structural bonding of bricks to concrete in heavy load applications, two-part epoxy adhesives offer maximum strength. Epoxies like Loctite Epoxy Heavy Duty deeply penetrate into concrete and brick for tenacious adhesion.
Follow all epoxy mixing directions carefully. Concrete surfaces must be fully cured and prepared properly prior to epoxy application.
Conclusion
Selecting the right brick adhesive involves evaluating factors like bond strength, flexibility, water/weather resistance, and cost. Heavy-duty epoxy adhesives provide the strongest structural bonds for brick-to-brick and brick-to-concrete applications. Polyurethane and silicone adhesives offer more flexibility and waterproofing for outdoor projects. Gorilla Heavy Duty Construction Adhesive provides excellent all-around performance at an affordable price point. With so many quality adhesive options available, there is a solution for any brick bonding application.