Spalling is concrete surface damage where pieces flake, chip, or break away from the main structure. It’s caused by freeze-thaw cycles, poor installation, water damage, or chemical exposure. Fixing spalled concrete involves removing damaged material, applying a bonding agent, and resurfacing with appropriate repair materials. The repair method depends on the damage depth and extent.

Understanding Concrete Spalling

Concrete spalling is a common problem that affects driveways, sidewalks, foundations, and other concrete surfaces. Recognizing what it is and why it happens is the first step toward effective repairs.

What Exactly Is Spalling?

Spalling is the visible deterioration of a concrete surface where fragments of the material break away, creating a rough, pitted appearance. It typically begins as small flakes or chips but can progress to larger chunks breaking off and deeper degradation if left untreated.

The damage usually starts at the surface and works its way deeper into the concrete. Early spalling might appear as:

Small flakes of concrete coming loose
Shallow pits or divots in the surface
Areas where the top layer has peeled away
Exposed aggregate (the stones in the concrete mix)

As spalling progresses, the damage becomes more severe with larger pieces detaching and deeper pitting. Advanced spalling can compromise the structural integrity of concrete elements, especially in load-bearing applications.

grinding to prepare spalled concrete for repair

Common Causes of Concrete Spalling

Several factors can cause concrete to spall. Understanding these helps prevent future issues and determines the best repair approach.

Freeze-Thaw Cycles

The most common cause of spalling in colder climates is freeze-thaw damage. This occurs when:

Water penetrates the concrete surface
Temperatures drop below freezing
The water expands as it turns to ice
This expansion creates internal pressure
Repeated cycles gradually break away the surface

Concrete in Fayetteville and similar climates with fluctuating temperatures is particularly vulnerable to this type of damage.

Poor Installation Practices

Installation problems that often lead to spalling include:

Using too much water in the concrete mix
Overworking or overfinishing the surface
Adding water during finishing (known as “blessing” the concrete)
Inadequate curing time or methods
Finishing while bleed water is still present

These mistakes create weaker surface concrete that’s more prone to spalling later.

Insufficient Concrete Cover Over Reinforcement

When steel reinforcement (rebar) is placed too close to the concrete surface:

Moisture reaches the steel more easily
The steel rusts and expands
The expanding rust creates pressure
This pressure forces off the concrete cover

This common issue in older structures can cause extensive spalling that requires structural repair.

Chemical Exposure

Certain chemicals accelerate concrete degradation:

De-icing salts (especially common on driveways and sidewalks)
Pool chemicals
Fertilizers
Acid rain
Industrial chemicals

Chemical damage often causes a distinctive pattern of spalling that may require specialized repair approaches.

As explored in the article about tree roots causing concrete damage, environmental factors play a major role in concrete deterioration, and spalling is no exception.

Evaluating Spalling Severity

Not all spalling requires the same treatment. Assessing the damage helps determine the appropriate repair method.

Determining Spalling Depth and Extent

Concrete spalling can be categorized by its depth and how much area it affects:

Severity Level	Depth	Coverage	Appearance	Recommended Repair
Light	< 1/8 inch	Isolated areas	Surface flaking, minor pitting	Surface treatment or coating
Moderate	1/8 – 1/2 inch	Up to 30% of surface	Noticeable pitting, exposed aggregate	Concrete resurfacing
Severe	> 1/2 inch	>30% of surface	Deep pitting, large areas affected	Full-depth repair or replacement
Structural	Varies	Exposes reinforcement	Visible rebar, compromised strength	Professional structural repair

To accurately assess spalling depth:

Clean the area thoroughly
Use a small ruler or depth gauge to measure the deepest pits
Determine what percentage of the surface is affected
Check if reinforcement is visible or close to being exposed

This assessment helps determine whether DIY repairs are appropriate or if professional intervention is needed.

When Spalling Indicates Serious Problems

In some cases, spalling points to underlying issues that require professional assessment:

Reinforcement corrosion – When spalling exposes rusted rebar, structural integrity may be compromised.
Widespread damage – Extensive spalling across large areas suggests fundamental problems with the concrete.
Progressive deterioration – Spalling that continues to worsen despite surface repairs indicates deeper issues.
Foundation spalling – Damage to structural foundation elements always warrants professional evaluation.
Commercial concrete – Spalling in commercial or public structures typically requires engineered repair solutions.

In these situations, consulting with our concrete repair specialists at AR Concrete Fayetteville ensures proper assessment and repair.

DIY Repair Methods for Light to Moderate Spalling

For light to moderate spalling without structural concerns, several DIY repair approaches can be effective.

Surface Preparation

Proper preparation is the most critical step for successful spalling repair:

Remove loose material – Chip away any loose or flaking concrete using a chisel and hammer.
Clean thoroughly – Use a pressure washer or stiff brush to remove all dust, dirt, and debris.
Treat stains – Remove oil, grease, or other contaminants with appropriate cleaners.
Check for soundness – Tap the concrete with a hammer; a hollow sound indicates more extensive damage beneath the surface.
Create a rough profile – Slightly roughen smooth areas around the spalled section to improve bonding.
Address any visible reinforcement – If rebar is exposed, remove rust with a wire brush and apply a rust converter.

Thorough preparation ensures the repair material bonds properly with the existing concrete.

Choosing the Right Repair Product

Several products are available for repairing spalled concrete, each with specific applications:

Polymer-modified cement patching compounds – Good for repairs from feather edge to 1/2 inch deep.
Concrete resurfacer – Ideal for thin applications over larger areas (typically 1/16 to 1/4 inch).
Epoxy mortar – Provides excellent durability for high-traffic areas or chemical exposure.
Vinyl concrete patching compound – Works well for shallow repairs up to 1/4 inch deep.
Sand/cement mixes – Suitable for deeper repairs but require proper proportioning and mixing.

The National Research Council’s Guide to Concrete Repair emphasizes that matching the repair material to the application is critical for long-lasting results.

Application Techniques for DIY Repairs

For best results when repairing spalled concrete:

Apply bonding agent – Brush a concrete bonding adhesive onto the prepared surface to improve adhesion.
Mix according to instructions – Follow manufacturer directions precisely for water ratios and mixing time.
Work in appropriate conditions – Apply repairs when temperatures are between 50-85°F (10-29°C) and no rain is expected for 24 hours.
Apply in thin layers – For deeper repairs, apply multiple thin layers rather than one thick layer.
Compact thoroughly – Press the repair material firmly into the prepared area to eliminate air pockets.
Create proper texture – Match the surrounding concrete texture for a more uniform appearance.
Cure properly – Keep the repair damp for several days by misting with water and covering with plastic.

These techniques significantly improve the durability and appearance of DIY spalling repairs.

Professional Repair Options for Severe Spalling

When spalling is severe, covers large areas, or affects structural elements, professional repair methods provide better results.

Concrete Resurfacing

For widespread surface spalling without structural damage, concrete resurfacing is often the most cost-effective solution:

Surface preparation – Professionals use specialized equipment like shot blasters or diamond grinders to prepare the surface.
Crack and joint treatment – Existing cracks and joints are properly addressed before resurfacing.
Primer application – A high-quality primer ensures proper bonding.
Overlay installation – A thin layer (typically 1/8 to 1/4 inch) of specialized overlay material is applied.
Finishing – The new surface can be finished with various textures and even decorative treatments.

Resurfacing can extend concrete life by 10-15 years when properly installed.

Partial Depth Repairs

For localized but deeper spalling damage:

Removal of damaged concrete – Specialists use concrete saws and chipping hammers to remove all damaged material to sound concrete.
Edge preparation – Repair edges are cut at slight angles to help lock in the repair material.
Reinforcement treatment – Any exposed reinforcement is cleaned and treated with protective coatings.
Specialized repair materials – High-performance materials with properties matched to the existing concrete are used.
Curing controls – Professional-grade curing compounds and techniques ensure optimal strength development.

These repairs integrate better with existing concrete and provide longer service life than typical DIY approaches.

Full-Depth Replacement

In cases of severe spalling that reaches deep into the concrete:

Complete removal – The damaged section is cut out entirely.
Base preparation – The underlying base material is examined and improved if necessary.
Reinforcement installation – New reinforcement is tied to existing reinforcement where appropriate.
High-performance concrete – Concrete with special additives for durability is used.
Proper joints – Control joints are installed to manage future cracking.

Full-depth replacement provides a completely new concrete section with the longest potential service life.

Preventing Future Spalling

After repairing spalled concrete, several strategies help prevent recurrence.

Concrete Sealers and Protective Treatments

Applying the right sealer is one of the most effective ways to prevent spalling:

Sealer Type	Best For	Application Frequency	Pros	Cons
Penetrating Silane/Siloxane	Horizontal exterior surfaces	Every 5-10 years	Breathable, doesn’t change appearance	No filling of existing cracks
Acrylic	Decorative concrete, light traffic	Every 1-3 years	Enhances color, UV resistant	Wears faster than other types
Epoxy	Garage floors, high traffic	Every 3-5 years	Very durable, chemical resistant	Not breathable, can yellow in sunlight
Polyurethane	Sealing over epoxy, UV exposure	Every 2-5 years	Excellent abrasion resistance	Requires careful surface prep
Lithium Silicate	Industrial floors, densifying concrete	Once (with occasional maintenance)	Hardens concrete, increases durability	Not a standalone water repellent

Choosing the right sealer depends on the concrete’s location, usage, and exposure conditions.

Drainage Improvements to Reduce Water Exposure

Since water is a primary cause of spalling, improving drainage around concrete surfaces helps prevent damage:

Proper slope – Ensure concrete surfaces slope away from buildings (minimum 1/4 inch per foot).
Gutter extensions – Direct downspouts away from concrete elements.
French drains – Install drainage systems in areas with persistent water issues.
Permeable borders – Create gravel borders around concrete to improve drainage at edges.
Joint sealing – Ensure control and expansion joints are properly sealed to prevent water infiltration.

These improvements significantly reduce the concrete’s exposure to moisture, addressing one of the main causes of spalling.

Winter Maintenance Practices

In Fayetteville and similar climates with freezing temperatures, winter maintenance practices greatly affect concrete durability:

Limit de-icing chemicals – Use sand or non-chemical traction materials when possible.
Choose concrete-friendly de-icers – If chemicals must be used, choose calcium magnesium acetate or other concrete-safe options.
Prompt snow removal – Remove snow before it melts and refreezes.
Apply sealers before winter – Ensure concrete is sealed before the first freeze.
Avoid metal shovels – Use plastic or rubber-edged snow removal tools to prevent surface damage.

These practices help minimize freeze-thaw damage, one of the leading causes of concrete spalling.

Long-Term Concrete Maintenance

Preventing spalling is easier and less expensive than repairing it. A comprehensive maintenance approach helps extend concrete life.

Regular Inspection and Early Intervention

Establishing a routine inspection schedule helps catch problems early:

Seasonal inspections – Check concrete thoroughly each spring and fall.
Document changes – Keep photos or notes to track any developing issues.
Look for early warning signs – Minor scaling, small cracks, or dark spots often precede spalling.
Address minor issues immediately – Seal small cracks and low spots before they worsen.
Check drainage patterns – Ensure water continues to drain properly away from concrete.

Early intervention on minor problems prevents them from developing into more serious spalling.

Professional Maintenance Services

For valuable concrete assets, professional maintenance services provide the highest level of protection:

Professional cleaning – Specialized equipment removes contaminants without damaging concrete.
Crack injection – High-tech epoxy or urethane injection stabilizes cracks before they cause spalling.
Joint renewal – Professional replacement of deteriorated joint materials.
Performance coating systems – Advanced multi-layer protective systems for high-value concrete.
Cathodic protection – For critical infrastructure, advanced systems can protect reinforcement from corrosion.

The concrete specialists at AR Concrete Fayetteville offer maintenance programs that help prevent spalling and other concrete deterioration issues.

Conclusion

Concrete spalling is a common problem where the surface flakes, chips, or breaks away due to freeze-thaw cycles, poor installation, water damage, or chemical exposure. While unsightly, its importance goes beyond appearance—spalling that’s left untreated often leads to more serious structural problems.

For light to moderate spalling, DIY repairs can be effective when proper preparation, appropriate materials, and correct application techniques are used. More severe or widespread spalling typically requires professional intervention with specialized equipment and materials.

Prevention is always the best approach, with concrete sealers, drainage improvements, and appropriate winter maintenance practices significantly reducing spalling risk. Regular inspections and addressing minor issues promptly can prevent the need for more extensive repairs later.

Understanding what causes spalling and how to address it properly helps property owners make informed decisions about concrete maintenance and repairs, ultimately extending the life and preserving the value of concrete structures.

What is Spalling and How Is It Fixed FAQs

Is concrete spalling just a cosmetic issue or is it a structural concern?

Concrete spalling begins as a cosmetic issue but can become a structural concern if left untreated, as the continued flaking away of surface material eventually exposes reinforcement steel to moisture and oxygen, causing corrosion that undermines structural integrity. The severity depends on the depth, extent, and location of the spalling, with damage to load-bearing elements like columns, beams, and structural slabs presenting greater risks than damage to non-structural surfaces like patios or walkways.

How can I tell if my concrete spalling needs professional repair instead of a DIY fix?

Your concrete spalling needs professional repair rather than DIY if it’s deeper than 1/2 inch, covers more than 30% of the surface area, exposes reinforcement steel (rebar), continues to worsen despite previous repair attempts, affects structural elements like foundation walls or support columns, or is accompanied by significant cracking or settlement. Professional assessment is particularly important for commercial properties, public structures, or any concrete that bears significant loads.

Does concrete sealer actually prevent spalling?

Yes, quality concrete sealer effectively prevents spalling by creating a protective barrier that blocks water, de-icing chemicals, and other harmful substances from penetrating the concrete surface. Research by the Portland Cement Association shows that properly sealed concrete can have up to 50% greater resistance to freeze-thaw damage, which is a primary cause of spalling, but effectiveness depends on using the right type of sealer for your specific situation, proper application, and regular reapplication according to the manufacturer’s recommended maintenance schedule.