How to Repair Your Concrete JointsConcrete is a fundamental element in construction due to its strength and longevity. However, even the most robust concrete surfaces are prone to wear and tear over time. Learning how to repair concrete joints can save significant costs and ensure safer spaces.

Types of Concrete Joints

Every concrete project, whether a sidewalk, driveway, or industrial warehouse, requires specific joints to cater to its unique needs.

Expansion Joints vs. Control Joints

There are two types of joints. Both types play a crucial role in managing stress, movement and preventing undesired cracks, ensuring the longevity of the concrete structure.

  • Expansion Joints: These are designed to allow structures to expand and contract with temperature fluctuations. They prevent cracks by providing space for concrete movement. Without expansion joints, there is a high risk of unexpected cracks and damage.
  • Control Joints: Purposefully designed to guide inevitable concrete cracks in specific directions and locations, ensuring that the visible damage is minimal and manageable.

3 Reasons Why Concrete Cracks

Concrete can wear out or sustain damage for various reasons, making concrete joint repair essential for maintaining a safe and aesthetic space.

  1. Temperature Changes: The consistent cycle of expansion and contraction due to temperature variations can lead to cracks.
  2. Settling: Over time, the ground beneath the concrete might settle, leading to uneven surfaces and resultant cracks.
  3. Stress: Areas exposed to heavy traffic or significant weights can crack due to stress.

The role of expansion joints is pivotal here. They accommodate these movements, and the risk of damage amplifies without them.

Different Types of Concrete Damage

With the reasons why concrete cracks in mind, concrete may accrue two different types of damage. 

  1. Cracks: These can appear for various reasons, from ground movement to heavy loads.
  2. Spalling: This refers to the chipping or flaking of the concrete surface. A combination of moisture penetration and freeze/thaw cycles often causes it.

Factors to Repair Method

The extent of the damage, the specific location, and the type of traffic exposure for the concrete surface determine the correct repair method.

Before diving into the repair, always ascertain the root cause of the defects. This assists in implementing the best long-term repair strategy.

  • Location: A sidewalk might require a different repair solution than a heavily-trafficked warehouse.
  • The extent of the damage: Minor cracks might need sealing, while deeper cracks or spalls might require more extensive repair.
  • Type of traffic: The repair method might differ based on whether the surface caters to foot traffic, vehicular traffic, or heavy machinery.

Concrete in Different Settings

When fixing concrete joints, the choice of material is pivotal. 

Whether you’re considering semi-rigid epoxies, rapid access fillers, or specialized solutions for colder environments, the right choice can determine the durability and longevity of the repair.

  • Sidewalk: These surfaces often interact with natural elements. They may face issues like weeds growing in cracks, water seepage, and wear from foot traffic. The repair methods here prioritize aesthetics and pedestrian safety.
  • Concrete Driveway: Driveways must bear the load of vehicles, making them prone to stress-induced cracks. Repairing a driveway requires durable solutions that can handle weight and vehicular traffic.
  • Warehouse: With heavy machinery and constant traffic, warehouses demand a robust floor structure. Ensuring joint integrity is paramount to avoid accidents or machinery damage.

Equipment and Tools

The right tools can make the difference between a job well done and a quick fix that might only last a short time.

Choosing the Right Equipment: Whether it’s a joint cleaning saw, a right-angle grinder, or a specialized tool, ensure it matches the repair method. For instance, a deeper crack might require more extensive equipment for proper repair. 

Handheld Tools for Minor Fixes: Simple handheld tools can sometimes address minor repairs or maintenance tasks. A razor scraper might suffice to remove the old filler, while a torch can help with specific adhesive applications.

Ensuring a Proper Bond: The success of any concrete joint repair largely hinges on the bond between the repair material and the existing concrete. Using vacuum systems and air compressors can help ensure a clean and optimal environment for bonding repair material.

Here’s a list of tools you’ll need:

  • Joint cleaning saw with dustless shroud or a right angle grinder
  • Removal blade
  • Braided wire wheel
  • Diamond blade
  • Vacuum system
  • Air compressor
  • Razor scraper/torch

The 2-Step Process to Concrete Joint Repair

Step 1: Use a joint cleaning saw or right angle grinder equipped with a braided wire wheel or suitable diamond blade to remove existing joint filler to a nominal depth of ½-inch below the surface, ensuring all filler residue is removed from joint walls back to clean concrete. Vacuum joint clean.

Step 2: Overfill the joint with an appropriate filler. Allow the filler to cure, then razor flush with the floor surface.

Products and Materials to Consider

Choosing a suitable filler is essential for optimal performance and longevity of the expansion joint. The product selection often depends on the project’s specific needs, traffic levels, and environmental conditions.

Choosing the right one for your repair needs can be a task with many products available. 

Here is a brief review of some industry staples:

  • Metzger/McGuire MM-80 Epoxy Joint Filler: An incredibly fast-setting epoxy ideal for semi-rigid requirements. Best used in areas with medium to heavy traffic.
  • Metzger/McGuire Spal-Pro RS 88 Polyurethane Concrete Sealer: This is known for rapid access repairs. It’s durable and sets quickly, making it ideal for projects with tight timelines.
  • Metzger/McGuire Spal-Pro 2000 or Spal-Pro RSF: These products are designed to perform optimally for those working in cooler or freezing conditions.

Concrete Expansion Joint Filler

The filler material you choose is important when maintaining and repairing expansion joints. Concrete expansion joint fillers are specially formulated to withstand the constant movement of the joint, providing a durable and flexible seal.

The ideal fillers for expansion joints are:

  • Elastic: They should be able to stretch and compress as the concrete expands and contracts without cracking.
  • Adhesive: They must bond securely with the concrete surfaces, ensuring the joint remains sealed even under stress.
  • Resistant: The fillers should be resilient to common elements such as water, UV rays, and traffic wear.

Protect and Maintain Joints

The material that fills expansion joints (like caulk or sealant) might deteriorate. 

Signs include:

  • Visible cracks.
  • Separation of the joint filler from the concrete
  • The presence of water or debris in the joint

To maintain your joints, make sure to:

  • Regularly inspect and clean joints to remove debris or any weeds.
  • Seal or reseal joints periodically to prevent water ingress.
  • If damaged, consult an expert to determine if a simple seal would suffice or if the joint filler needs replacement.

Common Misconceptions

Even within industry circles, myths about the best approaches to concrete joint repair can increase. Let’s set the record straight.

  • “All cracks are the same.” Not true. Cracks can result from various factors, including temperature changes, pressure, settling, etc. It’s crucial to identify the type and cause of the crack to treat it correctly.
  • “Repairing during any weather is fine.” Weather plays a significant role in how repair materials set and cure. Extremely cold or wet conditions can impact the efficacy of particular repair methods.
  • “Regular maintenance isn’t necessary.” Like all things, concrete undergoes wear and tear. Regular inspections and timely maintenance can save significant costs in the long run.

Concrete Joint Repair Is a Maintenance Investment

Concrete, with its durable nature, forms the backbone of many structures. 

However, like everything, it’s not immune to wear and tear. Investing in regular maintenance and timely repairs is about more than just aesthetics. It’s about ensuring safety, longevity, and functionality.

Should you have any questions regarding the processes discussed or the products mentioned, don’t hesitate to contact Runyon. Check out a successful Sam’s Club joint fill job to learn more about concrete joint repair.