How to Fill and Repair a Concrete Joint in 2 Simple Steps

How to Repair Your Concrete JointsYou are tasked with fixing a deteriorated floor surface. Before your begin the repair, it’s important to determine the cause of the defects, which will help you find the best long-term repair strategy for the project. Any structural causes will need to be corrected prior to filling a joint.

Joints can be filled three different ways, depending upon the extent of the floor’s deterioration. If the existing filler is well-bonded structurally to one or both sides of the joint, you can refill voids without removing it entirely, or making a partial removal. However, if the existing filler is not well-bonded or appears to be installed improperly, remove it completely before making the joint repair.

Three Considerations

Consideration 1: Select floor repair materials that meet the requirements of a facility’s operations. Consider frequency and type of traffic — foot, vehicle, heavy equipment. Also consider building temperature, the surface area to be repaired and the work window you have to complete the repair. This will help determine whether you need to use more rigid products for large repairs, if epoxy products will have the time required to cure or if you’re working in a freezer or cooler room.

Consideration 2: Prepare the surface for long-lasting repair by making sure the area is well-defined and cleaned properly prior to filling with repair material. Proper surface preparation is critical to a successful repair. Take care that the edges of joints, cracks and surface spalls are at least 1/2-inch deep and the area is not only clean, but dry prior to filling.

Consideration 3: Avoid a concave or dished joint by filling with repair materials slightly higher than the floor surface. Once cured, the excess material is ground or shaved to meet the original surface, restoring a smooth, continuous, flush profile across the floor.

Tools & Equipment

Repair Materials

The Process

Step 1. Use 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 surface, making sure all filler residue is removed from joint walls back to clean concrete. Vacuum joint clean.

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

Additional Resources

In addition to these tips, products and processes, please take a look at our YouTube page for specific joint repair videos taken during various training classes (presented by experts from Metzger/McGuire). Also, please comment below or contact us with additional questions, or visit our website for a full listing of Metzger/McGuire products.

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4 Common Surface Residues Explained for More Effective Removal

Before you can revitalize a floor with a new overlay, polish or seamless coating, built-up residues left behind by old flooring coverings must be cleaned and removed. Proper surface preparation for any flooring job is key to its success, ensuring that the new treatment will bond flawlessly with the substrate surface, creating a strong, long-lasting installation. Knowing the characteristics of each residue material can help in deciding the most effective removal process. Below is an explanation of the most common built-up residues and suggestions for removal.

MASTIC

Mastic is an adhesive with super strong bonding properties commonly used for setting tile. Builders also use mastic to seal windows, walls and ceilings. Mastic gets its name from the mastic tree, as it is derived from its resin droplets. However, mastic is also manufactured synthetically, which is generally less expensive.

  • Available in thin liquid, thick glue or paste form
  • Typically applied with a caulking gun for construction use
  • Used to join panels of concrete or asphalt
  • Quickly forms a permanent bond for a variety of materials
  • Works best on hard, non-porous surfaces
  • Known for heat resistance and durability
  • Can seep into cracks and crevices causing discoloration and general weakening

Key Removal Methods: Grinding, Shaving

THINSET

Made with cement and sand, thinset is an adhesive mortar often used to apply tile to floors, walls and countertops. Thinset gets its name because a relatively thin layer of compound – typically less than 1/4 inch (about 0.5 cm) – is used to bind objects together.

  • Available in powdered or premixed form
  • Typically applied with a notched trowel
  • Can be applied directly to the subsurface
  • Provides faster cure and dry times
  • Easier to use than mortar bed applications
  • Can be a brittle compound that tends to crack if the area shifts
  • Can be treated to increase flexibility, often with an acrylic compound additive

Key Removal Methods: Shotblasting, Buffing with a Swing Machine

EPOXY

Epoxy is a superior glue with high-level bonding power used to secure different types of metal, plastic or wood, and forms a hard layer of protection as well. Composed of petroleum products, epoxy gets its name from polyepoxide, which provides bonding strength. Epichlorohydrin provides its protection ability, as well as its resistance to humidity, moisture and temperature shock.

  • Uses a two-component system that requires mixing for activation just before use
  • Fast drying, strong bonds
  • Create an attractive layer of floor protection that lasts for many years
  • Virtually indestructible

Key Removal Methods: Grinding, Shaving

GLUE

Glue used to install hardwood, bamboo and vinyl floors, as well as carpet can, be made from a variety of components, including modified silicone polymers (MS+), polyurethanes and acrylics.

  • MS+ products generally form a mechanical bond with wood and a chemical bond with concrete, are unaffected by water, typically zero-VOC and eco-friendly
  • Polyurethanes form a chemical bond with wood and a mechanical bond with concrete – a strong, elastic bond that is also unaffected by water
  • Low VOC and generally contains solvents
  • Acrylic adhesives usually consist of polyvinyl acetate emulsions; the polymers fuse, creating what’s called a “particle entanglement” or matrix
  • Highly susceptible to moisture and usually require a flashing off period prior to floor installation

Key Removal Methods: Grinding, Buffing with a Swing Machine

To learn more about each method of surface preparation and removal, read our blog post, Remove Residue Build-Up with 4 Proven Methods.

3 Popular Concrete Densifiers Demystified

Concrete densifiers are also known as chemical hardeners. When applied to a concrete floor, a densifier fills empty spaces in the material and oftentimes forms a chemical bond with the concrete, changing its properties and increasing surface density.

Benefits of Using Densifiers

Densifiers are used specifically to improve the concrete surface when polishing. As long as free lime is present, the complete saturation of a densifier will make substrate harder, which allows a more aesthetically pleasing finish grinding and polishing, and prolongs the durability of the polish. Other benefits include:

  • Reduced dusting
  • Higher, deeper gloss than untreated concrete
  • Increased abrasion resistance and weathering
  • Longer floor lifespan
  • Locks in a topical color application
  • Stain resistance
  • Easier to clean

Types of Densifiers

Different types of densifiers create a chemical bond with concrete in a variety of ways. Runyon Surface Prep carries a wide selection of densifiers; below is a comparison of the three most popular.

Ameripolish – 3D Hybrid Silicate Densifier

  • Developed to help keep concrete looking newer longer
  • Improves performance of new, old or aged and existing concrete
  • Can be used with integrally-colored cements
  • Contains UV stabilizers to help protect color from fading
  • Penetrates fast for a deep seal
  • Hardens deep to improve durability even after grinding

Convergent Pentra-Sil Densifier

  • Developed to increase the integrity and life of concrete floors
  • Patented nano lithium hardener technology reacts with the concrete to produce calcium silicate hydrate (CSH), creating a strong, virtually impenetrable and durable finish with only one-coat and no rinsing
  • Resistant to bacteria

Prosoco Consolideck LS

  • Developed to improve the appearance and performance of architectural masonry
  • Gives new life to historic buildings, monuments, existing buildings, new masonry and reinforced concrete structures
  • Lithium silicate treatment reacts with the concrete to produce CSH
  • Safer, faster and easier to apply than conventional sodium or potassium silicate hardeners
  • Will not trigger or contribute to surface ASR (Alkali Silicate Reaction)
  • Resists damage from water

Get in Touch

If you have any questions about these three concrete densifiers, or if you’d like to purchase please visit our website or call us at 800.896.8665. We look forward to hearing from you!

The PORTAMIX MEGA HIPPO® – New Innovation For Faster On-Site Mixing and Pouring

New CS Unitec MEGA HIPPO MixerMuch of the effort and energy it takes to mix and pour cement, grout, mortar, texture coatings, sealants, adhesives and other self-leveling compounds can be alleviated by using a portable mixer such as a HIPPO mixer from CS Unitec. Now, you can further reduce your crew’s physical effort while boosting productivity and lowering labor costs with the newest portable mixer model.

Mix, transport and pour products even faster — and more easily — with the recently introduced PORTAMIX MEGA HIPPO® Mixing Station:

  • Mix, transport and pour up to six 50-lb bags in minute
  • One operator can accurately place material directly onto the floor
  • Mix in bulk and dispense into smaller containers
  • Excellent mix consistency and easy blend

How did a great mixer like the HIPPO get even better? The new MEGA HIPPO liner canister system makes quick work out of mixing multiple batches. The “Easy-roll Trolley” and the balanced “Easy-tilt Cradle” let you pour and spread material at the same time, eliminating multi-stage pours. Wheel covers keep casters free of screed splatter. Additional features:

  • Standard equipment includes mixing, motor, bucket, removable liner and two paddles
  • Specially shaped mixing bowl eliminates pockets of unmixed product
  • Full-brim capacity of 23 gallons or 350-lbs
  • Two 9″ diameter paddles with helix ribbon and side bars thoroughly mix colors and additives quickly
  • High-torque, 15 Amp, 2-geared motor
  • Liners are pliable and easily cleaned; alternating liners prevents cross contamination
  • Dust extraction port for vacuum connection

If you want to upgrade your concrete and cement mixing machines or portable mixer stations, Runyon Surface Prep carries a full line of CS Unitec concrete HIPPO mixers, paddles and hand grinders for all your surface preparation needs, including the new Portamix MEGA HIPPO model.

How to Use Glass in Decorative Concrete Countertops

ASG glass countertopToday, artisan crafted, decorative concrete or terrazzo countertops are growing in popularity, because each creation is not only unique, it’s also a masterpiece of design. The use of glass aggregate introduces a third dimension to the surface that plays off of light and color, creating a richness and depth worthy of its glorious shine.

Seeding Glass for Countertops

In this article, we’ll explore one of the most effective applications for creating unique and colorful countertops: seeding. Glass chips are sprinkled, broadcast or spread onto the surface of the concrete countertop (this application can also be used on a floor, slab or other surface). Even though it can be tricky to spread the glass uniformly onto the surface, artisans can use this technique to create customized, personalized or one-of-a-kind glass designs using less glass relative to other types of applications. Seeding can be accomplished in seven steps:

  1. Prepare and place your concrete as you normally do.
  2. Bull float the concrete to smooth out the surface, but don’t rough trowel or finish trowel your project.
  3. Spread the glass out evenly – or in a pattern – on your concrete surface using any quantity, colors and mixes of glass that you desire.
  4. Lightly trowel the glass into the still-wet concrete, gently pushing the glass into the surface, taking care not to push the glass too far in, or your finishing, grinding and polishing process will take longer. For a bolder finish, leave Pea gravel, compacted substrate, even some of the higher glass tips on the surface or sticking out of the concrete.
  5. Cure concrete for about seven days, enough time to avoid damaging the surface by finishing too early, or damaging your tools by finishing too late.
  6. Begin grinding the concrete surface with a 50-grit diamond grinding pad. Increase to a 100 grit, then 200 grit and continue increasing the grit until you achieve the finish and polish you’re looking for. Avoid scratching or scarring the concrete by wetting the surface during the entire grinding process to reduce friction between the pad and the concrete.
  7. Sweep, vacuum or wash the surface (often with muriatic acid) to remove dust. Apply a sealer of your choice, carefully following the manufacturer’s recommendations.

seeding glass diagram

When you’re looking for quality glass chips for use in decorative concrete countertops, count on Runyon Surface Prep. We carry American Specialty Glass products. ASG recommends adding an acrylic fortifier to the concrete mix to help with the adhesion of the concrete to the glass and other aggregates. Using a retarding product on your concrete surface before spreading the glass chips can also increase the working time.

*photos courtesy of American Specialty Glass

Use Terrazzo Glass in Decorative Concrete for a Truly Unique Look

Glass-Infused Concrete OverlayThe use of glass adds a unique decorative element to concrete. How the glass is applied, the quantities of glass used and the mixes of colors chosen creates a customized design for a floor, countertop or other decorative concrete product limited only by the imagination.

Glass is used to create the ancient art known as terrazzo, which uses chips of glass, marble or similar material fixed in tinted cement, then ground and polished to a smooth sheen. Its beauty was discovered by mosaic craft workers in 15th century Italy, after noticing how small marble chips left on a terrace pushed into the surface, smoothed by foot traffic over time. The effect not only makes the floor unique, it strengthens the surface as well. Nowadays, architects and designers all over the world use the extremely durable terrazzo to create one-of-a-kind floors using vibrant, modern colors and transform environmentally sustainable surfaces into a stunning work of art.

Common Applications of Glass in Decorative Concrete

In this article, we’ll explore one of the most common applications of glass in creating terrazzo: integrally mixing. The process replaces all or a portion of the aggregate in a concrete mixture with recycled glass chips, creating a uniform look of glass aggregate and concrete in the finished product. Integrally mixing uses much more glass than other applications such as seeding, which will be discussed in our next article.

Steps for Integrally Mixing

  1. Replace traditional aggregate content with recycled glass chips on a 50/50 or any other percentage. If a 6-bag mix that requires 100 lbs of aggregate per batch, replace all or a portion of the 100 lbs with glass. More glass provides a more colorful finish, whereas less glass leaves a more subtle color.
  2. Mix, pour, bull-float, rough trowel and finish trowel the concrete.
  3. Cure concrete for about seven days, enough time to avoid damaging the surface by finishing too early, or damaging your tools by finishing too late.
  4. Begin grinding the concrete surface with a 50-grit diamond grinding pad. Increase to a 100 grit, then 200 grit and continue increasing the grit until you achieve the finish and polish you’re looking for. Avoid scratching or scarring the concrete by wetting the surface during the entire grinding process to reduce friction between the pad and the concrete.
  5. Sweep, vacuum or wash the surface (often with muriatic acid) to remove dust. Apply a sealer of your choice, carefully following the manufacturer’s recommendations.

integrally mixing ASG glass

*photo courtesy of American Specialty Glass

When you’re looking for quality glass for use in decorative concrete like terrazzo, count on Runyon Surface Prep. We carry American Specialty Glass products. ASG always recommends adding the fine glass product (ground glass minus 30 mesh) to your mixture when glass aggregates are used. The silica in the fine glass chemically reacts well with the cement to better bond the concrete mixture to the glass. The fine glass is lighter in color and is great for subtle color effects in concrete.

5 Simple Steps to Keep Concrete Dyes from Fading

How to Keep Concrete Dye from Fading

Concrete dyes are an attractive way to add color to a concrete floor. However, because of the nature of dye — it penetrates the porous surface to create color, rather than reacting chemically with the concrete — contractors can conduct a few assessments and tests at the job site before determining whether a concrete dye is the right product for the job:

  1. Type of Concrete. Typically, a pure color dye will change slightly, due to the minerals in the concrete, taking on a lighter or darker shade, which can also change with time. Adjust the dye color to the type of concrete for the desired shade.
  1. UV Light Stability. Sunlight can damage dyed concrete floors, causing vibrant colors to fade. Check if windows in the room are made with glass containing UV-protection, which can keep floor color from fading.
  1. Moisture Vapor Test. When moisture in concrete brings salts to the surface, it causes dyes to seep deeper into the floor, diluting their color. Testing for efflorescence cannot only root out a bigger moisture issue, it indicates whether water will cause the color to diminish.
  1. Use Stain. Concrete stains work differently than dyes, reacting chemically with the concrete to create color that is more resistant to fading from sunlight or moisture.
  1. Apply Guard. A proper guard provides long-lasting, breathable protection for the floor and its color. Apply after polishing. 

Fixing Faded Floors

If the concrete floor is already fading:

  • Clean and seal the flooring surface to stop additional fading
  • Remove the sealer, then re-dye the floor and protect with sealer

When you’re looking for quality concrete dyes and sealers, count on Runyon Surface Prep. We carry two of the top-rated concrete dyes and sealant brands in the business. AmeriPolish products assure perfect color that resists fading through cleanings, scrubbings and traffic. Prosoco products are designed to improve the appearance and performance of architectural masonry for years to come.