Step-by-Step: How to Fix a Crumbling Garage Floor

A garage floor is intended to support the weight of vehicles as well as its contact with wheels. Health, age, and floor covering all play a role in the level of strength needed to provide a surface for a vehicle to stand on, especially without the unfortunate occurrence of damage in need of intense work rather than a simple patch job.

To fix a crumbling (also known as ‘spalling’) garage floor, there are preparations and steps to follow to lessen the chance of unsuccessfully doing such, which could cause the issue to worsen. Read further to learn how to apply several do-it-yourself steps to help your garage floor look like new.

Pick Up Chunks of Loose Concrete

Considering a garage floor is built from the soil, a grainy base, and a concrete slab, the three combinations can weaken over time. Water and vehicles which surpass the weight of an SUV are two common issues that tear away at the floor. The ingredients of concrete consist of air, cement, water, gravel, and sand.


When in contact with the other ingredients, air entrainment is intended to form pockets which relieve internal pressure on the concrete. This element is the result of the mixing process. However, giant bubbles can develop, and the concrete must be vibrated to resolve the issue. 


Although an ingredient in concrete, cement contains a crushed stone, which is a secondary addition for its slightly paste-like texture when mixed with water, it is interchangeable with concrete but is more so a liquid. 


The amount of water dictates the result of how loose or how thick the entire mixture of concrete maybe. A large amount equals low strength while a small amount equals consistency, which also may be difficult to spread. A percentage of 25% is the right balance in terms of the cement-to-concrete ratio.


One part of this is mixed with one part of sand and one part of water. But without it, concrete is lost as gravel is significant and the key in what makes concrete what it is. Sandstone, limestone, and basalt, all crushed together, are a combination of the stone particles cement contains.


This is made from rocks and minerals such as quartz, felspar, and mica. It binds the concrete for a firm hold and could be likened to a strong glue, which is difficult to remove.

The crumbling is gradual but becomes evident if the limit it can hold is reached despite how thick the depth it may be. But before that, cracking develops and then progresses into concrete, which finally breaks away from the base. 

This is a danger to the tires of a vehicle and could cause punctures. The chunks could also become embedded in the wheels.

Severe crumbling is a sign that a massive amount of moisture has affected the concrete. From the first contact with moisture, the deterioration begins if the issue is not fixed immediately. Otherwise, it will go on until the cement is pushed apart, which causes expansion, and the crumbling develops.

A poorly functioning draining system could be harmful to the strength of the concrete. This combats the depth of the floor, and toxic chemicals intensify its deterioration. Since the system is located underground and is in the form of a large pipe, the city is responsible for any issues which need to be fixed. 

Before the removal, look around to see if there is any clutter or items which could receive damage if in the wrong path, as you prepare to begin searching for chunks of concrete.  Cardboard boxes, glass bottles, or metal objects should be moved if they are too close to the inner part of the floor. 

Carefully examine the entire floor and dispose of any concrete, which is easy to pick up or remove. A mallet is an excellent tool to use to break off hanging chunks without much effort. Thick contractor gloves should be used to handle such a task to avoid scrapes or cuts to your bare hands.

Break Up Large Pieces for Easy Removal

Also, consider using a sledgehammer for thick concrete and pause in between every hit to build up the energy to use your strength. Sledgehammers are available in various sizes, but 12 lbs. should be suitable for you to accomplish breaking the concrete thoroughly. 

Do not swing the sledgehammer or lift it above your head. It is heavy and has been the result of many accidents (and deaths) because of improper use by inexperienced individuals. To hold it in a downward position, as it is leveled with your face while you are bending, is another dangerous method. 

Instead, hold the sledgehammer at shoulder length and allow it to drop down quickly on the concrete. Grasp it tightly to avoid it slipping out of your hands as well as the risk of injuries to your feet. Move your feet apart as you perform this action to ensure there is enough space to allow the sledgehammer to drop. 

Safety goggles should be worn to prevent fragments of the concrete, getting into your eyes as you use the sledgehammer. A ventilation mask can protect you from the inhalation of dust particles that are prone to fly around during a demolition task.

Wash Away Residue Build-Up

Garage floors tend to endure a massive amount of usage. This contributes to deterioration combined with the aging process. Although the damage is not noticeable in the beginning, and it is impossible to see on a visual basis, it gradually weakens the floor.

Use a bucket of water mixed with dishwashing liquid and a boar-bristle scrub brush. The pressure is powerful enough for you to remove any lingering residue. Pay close attention to the oil, which is known to be tough to wash and wipe away. Since oil also can seep into the concrete, depending on its thickness, only the top layer may be affected.

Allow the water to dry because wet concrete is challenging to work with. Then use a pressure washer to spray off the lifted residue while it deep cleans any remains. The water is strong enough to replace a towel, which would get dirty quickly if used for wiping. However, you can use durable paper towels to absorb the water because they are disposable.

Refrain from pointing the hose of the pressure washer toward yourself. The strength of the water is enough to harm you or worse. Instead, point the hose downward. Also, do such while the machine is off to avoid an accidental restart. According to the large size of the machine, keep it at a distance, although within easy reach, as you work.

A cleansing solution could also be used. Dilute the solution with water (half water and half solution) and then pour it into the pressure washer. Detergent, which is strong enough to remove stains, could be beneficial to remove old and new stains from the concrete. The same method pertains to oil, which could be faded with the help of the detergent.

Muriatic acid is another solution and is a particular type of acid that rips through the residue. But such a solution is dangerous and considered hazardous to use. The ingredients of the acid are what an individual should be cautious about.

Regarding contact with skin, just as any acid, you could suffer severe burns despite wearing gear, which you may think would ensure protection. If you do choose to use the acid, conduct research which will inform you about what you should and should not do and how to prepare for usage.

File the Broken Areas

Like a piece of tooth or fingernail which have broken off, the edges are sharp, exposed, and could cause damage. The same could have pertained to the edges of concrete. As a hazard, they can also puncture wheels and continue to break off until a whole new chunk is gone. 

It is essential to consider that tires could become embedded with loose concrete, which is difficult to remove. If a vehicle attempts to drive over the edges, the sound will be loud enough to make a driver cringe in fear for their tires. Therefore, a tool that can level the concrete should be used rather than a leveling compound solution.

For a minimal task, you can use an angle grinder. The tool is commonly used to blend the concrete with other areas and is versatile in its ability to cut tile, grind metal, and polish. An attached diamond wheel is essential because it is the vessel of the tool. The feature allows thorough grinding of various materials and surfaces.

When using the grinder, thick gloves are advised because the edges of the diamond wheel are sharp. With bare hands, you would be risking severe cuts or worse. The grinder works while flat and in contact with the surface. The possibility is allowing one of your hands to receive an injury. That injury could be one not easy to resolve with a bandage, either.

For a tedious task, you can use a diamond wheel, which is more extensive, especially in diameter, and can cut far more profound than the smaller version. Each blade is larger as well. However, you would have to hold the angle grinder at arm’s length to avoid an accident as well as to be cautious of its high power.

Turn the grinder off and remove the plug from the socket to ensure you do not accidentally flip the switch.

Use Cement as a Filler

Cement could be used for space between breakage and the concrete, which remains intact. Considering its pasty consistency and smooth texture, the application should be light, and the substance should be used sparingly. Although unstable when compared to concrete, cement is a more advanced version of a filling that provides a bridge within missing areas.

Often, cement is prone to cracking if used as a sole method of flooring. Water is usually mixed to create the consistency of the cement. The activation of leading ingredients such as calcium, iron, and aluminum is its bases.

  • Calcium: Hydration is provided in cement with the element of calcium. It plays a part in protection from the damage of freeze as a result of snow and its transformation to ice. Also, a below zero temperature is combatted.
  • Iron: The color of cement is attributed to iron and dictates the strength and hardness of the cement.
  • Aluminum: When combined with cement, a hydrogen gas develops and could cause corrosion, which contributes to the cracking of concrete.

Cement is weaker than concrete and is a valid reason to not rely solely on it in terms of flooring. It is prone to crack as well as break off far quicker and can revert to its wet state when in contact with heavy rain, for instance.

Apply the cement with the margin trowel for a smooth application. Spread the cement gently while paying close attention to the layer. Go over the area once again with more cement and then move on to the next area.

After applying the cement, allow it to dry and then cover the missing areas with a fresh batch of mixed concrete. This method is intended to ensure the areas will be less obvious and will blend in with the first layer of concrete. The thinner the application of cement, the more natural it will look.

Natural drying of the cement is advised rather than to force the process. For instance, using a blow dryer as a quick method will not do such without blowing the cement off the area. This method could also cause the cement to bulge, which could ruin the layer. The use of a fan could result in the same issue.

Resurface Rather Than Replace

To resurface is to start with a fresh new top layer of concrete only. Perhaps two or three layers are better to be on the safe side. Depth makes a difference, and much depends on the thickness which an individual prefers.

However, to replace a floor could take time and effort to do while having to start from scratch. The floor would have to be demolished, and then a rebuilding process would have to take place. Therefore, it is far better to resort to resurfacing as it is more comfortable in terms of the illusion of revitalization.

Several standard tools are needed, such as a push broom, bucket, squeegee, power mixer, concrete edger, pressure washer, finishing broom, and control jointer. These tools help in applying, flattening, smoothing, and edging. 

Professionals advise that each tool should be used as directed because they all have individual uses for personal reasons. Therefore, depending on the recommended order, a successful result is more likely. What is not recommended is to attempt a short cut. Impatience could only breed a negative result when resurfacing.

You do not have to be an expert to perform this task, but learning how to do so as you go along could save you the trouble of struggling to replace the entire floor. When you are ready for the task, work slowly to avoid losing your concentration while inviting the risk of a mistake. It is easy to make a false move, and the area could be compromised as a result.

Use a Strong Floor Covering as a Sealant

Two types of sealants could be used to complete the process of the fresh rejuvenation of the floor. One is film-forming, and the other is penetrating. 

The former starts as a thick, clear syrupy substance that is usually poured and then spread with a paintbrush or paint roller. It is vulnerable to absorption, which wears on the finish over time. The latter prevents water from seeping into the finish and is a repellent.

A sealant has a combination of ingredients that are a significant part of its texture and how it affects the concrete. It is likened to that of a shield and is available in the form of a liquid which dries firmly. Whether a low gloss or a high gloss, the intention is a shiny finish.

Acrylic Resin

Acrylic resin is a latex paint that protects the concrete and should last at least five years to a decade. It forms a film resistant to scratching, scraping, and will not develop discoloration from the sun. Cracking is another factor to avoid after the paint dries and does so quickly.


Upon the choice of a protectant of a high level, epoxy is a common choice. This provides a strong repellant against water, dirt, dust, and other particles, which could contribute to the deterioration of a bare concrete floor. The primary color is exact, but the sealant is also available in pigmented shades.

garage floor


Concrete is deeply penetrated by silane and forms a barrier that causes water to bead off the surface. It is evident with the consistency of syrup and dries with a shiny finish.


Although weaker in terms of penetration, siloxane provides enough protection from elements such as heavy rain, snow, and rock salt. It is water-based and straightforward but can also be tinted aside from the exact primary color.

For the application of a sealant, professionals use familiar tools such as a spraying agent for a solvent-based sealant and a roller for a water-based sealant. There are differences between both that should be distinguished before the usage of one or the other.

Solvent-Based Sealant

The finish of this sealant is a high gloss while it darkens concrete and is prone to increased color development. It penetrates very well and has a ‘wet look.’ Most likely, a strong odor will be present until it fades over time.

Water-Based Sealant 

Regarding this type, the gloss is low, concrete has less of a chance of darkening, and its chemical resistance is high. The finish is matte, slightly dull, and is not flashy. It carries a mild odor, and the cleaning process is easy.

Depending on which sealant you choose, use such sparingly as a moderate amount could go a long way. A large amount could take days to dry as well as fail to dry smoothly. Wear protective gear such as work gloves, goggles, and a protective face mask to avoid inhaling fumes, which could be toxic and nearly undetectable.

Consider Other Floor Coverings

There quite a few additions to consider after the entire flooring task is complete. A sealant is not a required substance to use and is a matter of an individual’s personal preference. While it is suggested to provide a slippery surface, which is also a repellant, it is merely one of many choices.

Some individuals prefer to use a covering that contrasts with a plain covering appearance. They want to drift away from the standard choice of the glossy finish. The choices vary depending on what one either does or does not find attractive. It is mainly based on what meets the eye, whether its edgy, soft, industrial, wooden, or merely a solid color.


Interlocking tiles are commonly used and consist of polypropylene plastic. The tiles are hard but prone to crack as a result of stress and weight over time. Also, they can chip and shatter before irreparable damage with no other choice but to replace the tiles which are affected.

Roll-out Vinyl

This flooring is versatile and is used in kitchens, living rooms, and bathrooms. It is inexpensive but quick and easy to install. The material is like paper, yet thicker, and is available in a variety of styles such as hardwood, artistic patterns, worn wood, and sandstone.


A grain of carpet, which is thin, is enough density rather than carpet, which is thick. However, a vehicle’s tires may or may not do more harm than good. Carpet is durable in some cases, in terms of a mass amount of walking, but tires carry more weight combined with the friction as a result of contact. The worse that could happen is the burning of the carpet or large holes.


Latex paint and oil paint are two choices. The former contains water combined with vinyl and acrylics, and the latter is pigmented but dries slowly. The stained appearance can provide concrete with the illusion of a finish that is old and worn.

Paint: Wall paint is yet another choice for a finish, but such is weak and vulnerable to every potential damage factor. The most damaging is water, which could cause the paint to peel or chip. It can be pulled off manually and is considered a vanity method with no benefits whatsoever.

Rubber Tile

Flexible enough to bend or fold completely, rubber tiles are moderately soft and comfortable on the concrete. In general, the rubber material is prone to tearing as a result of aging. It is not made to handle the weight nor friction of tires and loses its texture as it is used. Also, it does not provide a stable surface for the tires to sit.


The hardness of the stone is essential in terms of support. Considering it is made from particles of various crushed rocks, it offers a reasonable amount of insulation. The surface is sturdy, durable, and can handle heavy objects. On the other hand, it is expensive, depending on how much is needed and the pricing, which varies.


Porcelain is made from refined clay, which is the basis of its durability. The surface could be mosaic, wooden, or stone. For a trendy or modern appearance, porcelain in the form of a tile is less porous than regular ceramic tiling. It is durable enough to maintain through cold and humid temperatures.


A mat is intended to provide a covering for a small area. Although it can run complete and lengthy, it can only cover enough for a vehicle or multiple objects to sit. Small garages are still too widely spaced to be covered entirely with one mat. However, multiples of the same mat of the same texture could be used as one entire mat.

Use a floor covering which best fits your preference and which you think will be attractive. Although some are placed on a higher level than others, it is not a guideline to use one type of covering on one or multiple floors.

Reflect on the Importance of DIY Garage Flooring

Not only is this method a money-saver, but it also provides an individual with the knowledge to fix their floor without supervision or a professional. Despite the duration of the task, trial and error is part of the process. When done more than once, and only in large gaps as the flooring should not need resurfacing so soon, it could become second nature.

Resources are available at an individual’s fingertips, and techniques could be included to form additional ideas aside from the basics. All while being cautious, you could become better at performing the task and may gain enough skill to help others who do not possess such at all.

One fact of the entire process is that DIY garage flooring is essential for an individual who wants it done their way and on their terms.

With the use of the ‘How To’ steps, the DIY process should not be difficult to complete. But how that process will fair, in terms of one which will be successful and accomplished, is up to you.