Basics of Resurfacing Concrete

Concrete resurfacing is the process of placing a new wear surface on existing concrete to restore or enhance its appearance and performance. There are several reasons to consider concrete resurfacing, and various methods and materials to achieve the desired results. This comprehensive guide covers the basics of when, why, and how to resurface concrete.

When to Consider Concrete Resurfacing

Concrete resurfacing is an ideal solution in many scenarios:

Worn or Damaged Concrete

Over time, concrete can become worn, stained, cracked, scaled, or generally deteriorate. Resurfacing renews the surface without the cost of full replacement. It is a budget-friendly way to update the look and function.

Slippery or Unsafe Concrete

Concrete resurfacing using coatings, sealers, or textured finishes can significantly improve traction and safety. This is especially useful for pool decks, patios, walkways, driveways, and commercial spaces prone to slip hazards.

Outdated Stamped or Colored Concrete

Stamped or colored concrete can become dated over the years. Resurfacing provides affordable options to update the look with new stamp patterns, colors, textures, and designs.

Poor Initial Appearance

Deficiencies in the original pour or finish of concrete often necessitate resurfacing. Issues like low spots, rough textures, color variations, and more can be cost-effectively corrected.

Changing Commercial Needs

Warehouse floors, manufacturing facilities, commercial kitchens, and other commercial spaces may require changes in surface finish to suit evolving needs. For example, increasing traction or cleanability.

Why Resurface Concrete

There are several key benefits that make concrete resurfacing an advantageous and popular option versus full replacement:

  • Cost Savings: Resurfacing averages 50% or less of the cost of new concrete installation.
  • Time Savings: Resurfacing can be completed in a fraction of the time compared to removal and replacement. Most applications take just 1-3 days.
  • Minimal Disruption: Existing concrete remains largely undisturbed, reducing demolition mess and simplifying preparation.
  • Existing Concrete Preserved: Resurfacing preserves the integrity of the substrate, utilizing the remaining service life of existing concrete.
  • Customization: A wide range of colors, textures, designs, patterns, and performance enhancements are possible.
  • Enhanced Function: Options like increased slip resistance, chemical resistance, abrasion resistance, and tensile strength.
  • Sustainability: Extending the service life of existing concrete is environmentally friendly. Landfill waste is minimized.
  • Aesthetic Improvements: Dated, worn, damaged, or poorly finished concrete can be beautified and modernized.

For most applications, concrete resurfacing provides ideal solutions more efficiently and cost-effectively than demolishing and replacing concrete. The variety of materials and methods available make it a versatile design approach.

How to Resurface Concrete

There are several main categories of concrete resurfacing materials and methods:

Concrete Overlays

Concrete overlays involve pouring a new layer of concrete material over the existing surface. Traditional concrete, polymer-modified concrete, and self-leveling overlays are among the top options:

  • Traditional Concrete Overlays: Typically 2-4 inches thick. Requires extensive preparation for successful bonding. Ideal for comprehensive repairs and thick resurfacing jobs.
  • Polymer-Modified Concrete Overlays: Integrates polymers to improve adhesion, durability, and strength. Reduces preparation needed and performs well as low as 1/2 inch thickness.
  • Self-Leveling Overlays: Flowing, self-leveling cement-based materials as thin as 1/4 inch. High-performing resurfacing for decorative options with minimal preparation.

Toppings and Screeds

Thin layered toppings provide cost-effective resurfacing for decorative concrete and improving wearability:

  • Colored Cement-Based Toppings: Applied 1/8 to 1⁄4 inches thick. Available in wide variety of colors with options like integral color, antiquing, and staining.
  • Dry Shake Color Hardener: Colored granules hand broadcast and worked into the surface during final finishing. Enhances abrasion resistance.
  • Liquid Dyes: Penetrating dye solutions allow color effects without changing surface texture. Limitations exist for badly damaged concrete.
  • Textured Toppings: Adds slip resistance and aesthetic appeal. Seeded aggregates, splatter textures, broom finishes, and imprinting are examples.
  • Metallic Toppings: Composed of proprietary materials like metallic aggregates, powdered metals, and pigments to achieve brilliant reflective metallic visual effects.

Stains and Dyes

Concrete stains produce translucent effects by chemically reacting with the concrete surface:

  • Acid Stains: Produce variegated marbling effects reminiscent of natural stone like slate or marble. Hydrochloric acid blends with concrete’s natural mineral deposits.
  • Water-Based Stains: Safer to use and better color stability than acid stains. More uniform, less mottled look.
  • Dyes: Penetrating liquid dyes create more uniform solid colors than stains. Limitations based on concrete condition.
  • Hybrid Stain/Dye: Combines stains and dyes for versatility. Customize colors from subtle tints to bold opacities.

Coatings and Sealers

Protective and decorative coatings in various sheens, textures, and thicknesses:

  • Clear Sealers: Protect against water, oil, stains, chemicals and wear without altering appearance significantly. Ideal for decorative concrete.
  • Color Sealers: Tinted sealers that penetrate and guard concrete with translucent color effects. Enhance vibrance of integrally colored concrete.
  • High-Build Coatings: Thicker acrylic, polyurethane, and epoxy coatings create glossy finishes and protect floors. Ideal for commercial and industrial floors.
  • Anti-Slip Coatings: Provides traction using coatings embedded with skid-resistant ceramic aggregates, sand, or carborundum grits.
  • Epoxy Flake Systems: Apply decorative and protective multi-layer coating with broadcast colored flakes. Provide vibrant floors resistant to chemicals and UV light.

Concrete Resurfacing Process Explained

The step-by-step process will vary based on the size of the project, conditions of the existing surface, and the products used. Here is a general overview:

  1. Clean and Prepare Surface: Remove coatings or adhesives. Clean thoroughly using pressure washing, scrubbing, scraping, and degreasing as needed. Allow to dry fully.
  2. Soundness Testing and Patching: Check for hollow or debonded areas requiring repair. Saw cut and patch major spalls, cracks, deteriorated areas.
  3. Profiling Surface: Roughen surface using grinding, scarifying, shot blasting, or acidic etching. Ensure proper surface profile for overlay bonding.
  4. Apply Bonding Agent: Choose appropriate bonding agent for overlay material. Apply to properly prepared substrate.
  5. Mix and Apply Overlay: Prepare and mix resurfacing products according to specifications. Proper proportions and mixing equipment are essential for quality results. Apply using trowels, squeegees, or screeding as required.
  6. Finish Decorative Options: While overlay is still wet, imprint patterns, seed aggregates, apply top coatings, broadcast flakes, and other decorative effects as desired.
  7. Cure and Protect: Allow proper moisture retention and protect surface during the critical early curing stages according to product guidelines.

Tips for Successful Concrete Resurfacing

Attention to detail in surface preparation, product selection, mixing, application, and curing leads to long-lasting, high-performing results:

  • Test surface pH and moisture content to identify needed prep steps.
  • Thoroughly clean and create an appropriate surface profile for bonding.
  • Follow all manufacturer’s mixing and application instructions precisely.
  • Use the specified tools and techniques to ensure proper thickness and finish.
  • Apply decorative options like flakes or imprinting at the right stage.
  • Adhere to all listed cure times and protection methods.
  • Address all existing cracks and joints appropriately based on overlay material.
  • Isolate overlays from vertical surfaces using foam tape or caulking to prevent cracking.
  • Consider control joints to manage overlay shrinkage and thermal expansion.

With the right approach and products, concrete resurfacing can provide property owners beautiful, cost-effective, long-term concrete surface solutions. Many municipalities even offer rebates for certain concrete enhancements like slip-resistant coatings. Working with experienced concrete resurfacing contractors ensures proper execution.

Frequently Asked Questions About Concrete Resurfacing

What is the cost to resurface concrete?

The cost of concrete resurfacing averages $2 – $8 per square foot depending on the type of product used and prep work required. It ranges from 50% to 75% less than full concrete replacement.

How long does concrete resurfacing last?

With proper installation and care, some systems like colored overlays and coatings can last 10-15 years or longer. Performance depends on factors like concrete condition, surface preparation, and type of products used.

Can you apply new concrete over old concrete?

Yes, installing a concrete overlay is a very common concrete resurfacing technique. It requires thorough cleaning and roughening of the old concrete first to ensure proper bonding.

What is the minimum thickness for a concrete overlay?

Overlays can be applied as thin as 1/4 inch for some materials, like polymer-modified and self-leveling concrete. Traditional concrete overlays often require a thicker profile of 2-4 inches.

What kind of coating is best for resurfacing concrete?

Epoxy coatings offer excellent adhesion, durability, and customization for concrete resurfacing. Polyurethanes and acrylics are also popular options with various levels of performance. Professional guidance is recommended.

How long does it take to cure a concrete resurface?

Cure times vary based on temperature and product used, but most resurfacing projects can return to service within 24 hours. Full cures take 28-90 days. Proper curing is vital for performance.

Can you apply epoxy over existing concrete?

Yes, high-build epoxy coatings and epoxy flake flooring systems are excellent options for resurfacing concrete. The surface must be properly prepped and primed first for coating adhesion.

What is the difference between concrete dye and stain?

Penetrating dyes create uniform solid colors while reactive stains have a variegated, mottled appearance. Stains chemically react with the concrete, while dyes color mainly the surface.

How do you prepare old concrete for new concrete?

Existing concrete must be thoroughly cleaned and given an appropriate surface profile. Methods include acid-etching, grinding, scarifying, and shot blasting. Apply a bonding agent before pouring new concrete.

Resurfacing existing concrete opens up exciting possibilities to enhance both the appearance and performance of worn or outdated concrete surfaces. Following proper procedures and consulting concrete resurfacing professionals ensures excellent long-term results. With some creativity, nearly any look, texture, or functionality can be achieved.

The Many Benefits of Concrete Resurfacing

Concrete resurfacing delivers property owners, facility managers, and contractors a versatile, affordable solution for rejuvenating damaged or outdated concrete. Here are some of the top benefits that make it advantageous over full concrete replacement in many scenarios.

Cost Savings

The primary appeal of concrete resurfacing is the significant cost savings versus demolition and installation of new concrete. Resurfacing costs average between 50-75% less than concrete replacement. The exact savings achieved depends on factors like:

  • Size of the area
  • Amount of surface preparation required
  • Type of resurfacing products and system used

Since resurfacing preserves the integrity of the existing concrete slab, costs are mainly limited to cleaning, prep work, materials, application, and decorative options. No expenses of full removal, grading, forming, reinforcement, and pouring new concrete from scratch.

Concrete resurfacing allows stretching concrete improvement budgets. Projects like sidewalks, driveways, pool decks, patios, and interior floors become more affordable. The variety of options enables customization at reasonable prices.

Enhanced Appearance

Resurfacing transforms the aesthetic appeal of worn, damaged, deteriorated, or outdated looking concrete with modern solutions. Here are some of the looks attainable:

  • Brand new looking concrete
  • Bold colors or intricate stained effects
  • Realistic brick, stone, wood, or tile patterns
  • Slip-resistant finishes
  • Reflective metallic shine
  • Custom logos and designs

New stamping, coloring, texturing, patterning, stenciling, staining, and coating techniques breathe life into existing concrete. It can appear like a completely new, dramatically upgraded surface.

Improved Performance

In addition to beautifying concrete, resurfacing enhances performance characteristics like:

  • Bonding strength with underlying concrete
  • Compressive strength
  • Tensile strength
  • Impact resistance
  • Abrasion resistance
  • Chemical resistance
  • Traction and slip resistance
  • Crack bridging ability
  • UV stability against fading

Polymer-modified materials, fiber reinforcement, underlayments, and protective coatings upgrade structural, safety, and protective properties.

Low Maintenance

Quality concrete resurfacing systems are formulated for durability, resilience, and protection from moisture, stains, traffic, UV rays and other elements. Minimal maintenance is required beyond general cleaning.

With proper installation and care, resurfaced concrete can last 10-15 years or longer before reapplication may be desired. Some thin applications like stains, dyes, and clear sealers may require more frequent renewal.

Quick Installation

Resurfacing saves vast amounts of time compared to full removal and replacement of concrete. Most projects take just 1-4 days, depending on the scope. Facility or home disruptions are kept very brief.

The existing slab remains largely undisturbed, avoiding lengthy demolition. After cleaning and roughening the surface, new materials can be applied efficiently. Fast access after completion is a major advantage of resurfacing.

Sustainable Solution

Repurposing existing concrete foundations is a sustainable solution. Landfill waste is significantly reduced compared to demolition and disposal of old slabs.

Resurfacing extends the useful life of concrete substrates, preserving the energy and resources invested in original installation. The average 25-year life span of exterior concrete can often be doubled with professional resurfacing.

Ideal for Phased Improvements

Incremental resurfacing projects allow flexibility in cost and disruptions. For example, an outdoor space might be upgraded over time:

  • Year 1 – Resurface pool deck
  • Year 2 – Update patio
  • Year 3 – Refresh sidewalks and driveway

Multiphase projects are much simpler than demolishing and pouring all new concrete simultaneously. Resurfacing empowers homeowners to refresh spaces gradually according to budget and needs.

Concrete resurfacing provides invaluable benefits at all scales, from small residential jobs to expansive commercial projects. Consultation with experienced applicators ensures optimal solutions for each unique situation and surface.

Key Considerations for Successful Concrete Resurfacing

Though concrete resurfacing can seem straightforward on the surface, appropriate planning, preparation, product selection, installation, and care are vital to achieve lasting, quality results. Here are some of the most important considerations and best practices to incorporate from the start:

Gather Background Information

Understanding the conditions and service requirements of the existing concrete is crucial background knowledge.

  • What is the original concrete mix design? Composition directly impacts bond.
  • What is the concrete thickness? Thinner slabs have higher risk of cracking.
  • What is the joint spacing? More closely spaced joints help manage overlay cracking.
  • What is the concrete condition and soundness? Identify needed repairs.
  • How old is the concrete and what is its service history? Age and wear influence preparation needed.

Conduct Testing

Key diagnostics to perform prior to resurfacing:

  • Compressive strength testing ensures the concrete is structurally sound.
  • Moisture vapor transmission testing indicates if moisture mitigation treatments are required before installing coatings or polymer overlays.
  • Surface pH testing identifies needed etching or neutralization prior to coatings.

Clean and Profile Surface

Robust surface preparation promotes excellent bonding and performance. Steps include:

  • Cleaning using pressure washing, detergents, degreasers, etc.
  • Grinding or shot blasting to roughen surface and remove laitance.
  • Etching with acids provides grip for overlays.

Select Appropriate System

Consider factors like cost, durability, aesthetics, and usage when selecting resurfacing products. For example:

  • Polymer-modified overlays offer high-strength and flexibility for exterior use.
  • Epoxy coatings provide optimal chemical and abrasion resistance for industrial shop floors.
  • Stains and dyes create beautiful, natural looks for residential patios.

Reputable manufacturers provide guidance on product selection and combinations for different needs.

Proper Mixing and Application

Adhere precisely to all instructions for mixing, installation tools, application techniques, thickness, and stages. Carefully measure components, mix thoroughly, and work freshly mixed product. Contractors with proven experience have the skills to execute properly.

Allow Adequate Curing and Protection

Observe all guidelines for:

  • Moisture retention like plastic sheeting over fresh overlays
  • Protection from traffic, chemicals, etc. during the cure
  • Temperature and time duration to full cure before exposure

Patience leads to strong, lasting results. Premature use risks bond failure, scratches, staining, and other issues.

Concrete resurfacing offers transformative solutions when executed appropriately.Paying attention to details in planning, surface preparation, installation, and curing prevents problems and leads