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Levelling garage flooring prevents surface problems from becoming deep, structural problems. Secondly, levelling a floor is essential if you want to place flooring over the concrete slab.

DIYers can only manage minor levelling problems such as cracking (caused by an uneven surface) or shallow dips (caused by pouring issues).

Both of these problems can be easily fixed! Any job that requires pouring mortar or floor levelling cement should be left to the experts! These jobs require a mud-jacking or foam injection repair. 

Attempting to fix this by yourself may result in damaged concrete floors. It’s very difficult – if not impossible – for an individual to apply a uniform layer of concrete over a large space.

As a result, the thin veneers will not form a secure bond. Within months your concrete garage floor will look worse than ever and will require extensive, structural repair. 

This is the definitive guide to levelling a garage floor. For convenience, we’ve included all the steps from start to finish. It’s a guide that allows the eventual laying of even and great looking garage floor tiles

Remember, It’s a great idea to get professional help if you are a little unsure about how to level the floor. Investing in quality help will pay off later! Without further ado, this is how to level a garage floor.  


How to Level a Garage Floor Professionally 

How to Level a Garage Floor Professionally

Now, levelling an entire concrete garage floor is a job that should be done by professional layers. However, it is good to have a grasp of the different techniques out there.

We want you to make an informed choice on how to level the floor.

You don’t always have to choose the DIY method. Polyurethane foam and mud jacking might be better options for your garage.

They will be more expensive, but they are definitely worth it. Especially if you have a structurally damaged floor or tile.  For peace of mind, find  a concrete layer that adheres to building codes and has good reviews. 

Mud Jacking 

Mud jacking can completely transform your concrete. Mud jacking will save your unlevel floor from structural damage due to its compressive strength.

Mud jacking will be the best option for a residential garage that has no specific weight sensitivities. It is more affordable than polyurethane foam injections.

It is also dramatically less expensive than replacing the whole concrete floor. Mud jacking does require heavy, loud equipment. However, the job will be done within a day.

Note that mud jacking does not remove any cracks or dents that have appeared as a result of the damage. 

Tools: 

Material: 

Step One: Drill Holes in the Slab

Firstly, you will need to make holes throughout the concrete slab. The holes should be about 1-2 inches in diameter and have a reasonable depth.

Make the holes with an electric drill or hose that can easily penetrate hard surfaces. 

The holes will be placed in targeted, strategic locations. Generally, there will be around 3-5 holes, spaced evenly throughout the concrete slab.

It requires a lot of skill and expertise to know where these holes should be placed. 

Step Two: Inject the Slurry

The holes are then injected with slurry. The slurry is sent through a hose that connects to the portable mixer. It is pumped into the 3-5 holes in the concrete.

Slurry is essentially a mix of cement, sand, and water. It is more fluid than cement but dries just the same.

The injected slurry will push the floor upwards until it is completely levelled with the garage door.

It is very tricky to do this as too much slurry in one place will exacerbate the problem and may even break the whole slab.  

Step Three: Patch Holes 

As slurry hardens it naturally fills in the crevices of the space. Slurry will also begin to harden as soon as it has been applied.

Within a couple of hours, it will be solid and secure. However, it will take up to a day for the slurry to cure its strength and level the floor. 

Step Four: Step Four: Level Concrete

After the labourers have checked the concrete has returned to its original slope, they will begin to level it out.

The holes will be filled with concrete patches and levelled off for a smooth finish.

You will still be able to see patches of fresh concrete for at least six months after the repair. Over time the patches should blend into the original tone. 


Polyurethane Foam for Concrete Garage Floors

Polyurethane Foam for Concrete Garage Floors

Polyurethane foam injections are a great, effective option for leveling out an uneven concrete floor. Technicians are able to predict the expansion of the foam, which makes this a predictable and reliable method.

Slurry-based jacking techniques are generally cheaper than slab jacking. This is because polyurethane foam is harder to source and thus more expensive. 

Polyurethane foam is lighter than slurry. The lighter base product is often preferred for weight-sensitive areas.

Talk to your builder if you have questions about the different types of concrete garage floor coatings. 

This is how to slab jack a concrete floor with polyurethane foam. 

What You’ll Need: 

Tools: 

Material: 

Step One: Drill Holes in the Slab

Firstly, holes will need to be made throughout the concrete slab with a high intensity electric drill. The holes should be about 1-2 inches in diameter and have a reasonable depth. 

Step Two: Inject Foam

The polyurethane foam must now be injected into the holes with a professional injection foam gun. The foam eventually expands and levels out the concrete. 

Step Three: Patch Holes 

Now, the holes must be patched with concrete covering the whole area. The mortar must fill the entire hole in order for the surface to turn out smooth. 

Step Four: Level Concrete

Leveling concrete will then be finished with a screed machine to create an even surface. 


DIY Instructions for Cracks and Shallow Dips

This is our step-by-step guide for leveling, flattening, and repairing concrete garage floors. Make sure you have done thorough research before you start the project.

Lack of preparation can result in problems.

Take your time choosing the right materials and equipment. We recommend paying a little extra for high quality products.

Your garage floor should last a lifetime. Investing in the best will ensure its longevity! 

What You’ll Need

Tools: 

Material:

Step One: Clean the Concrete Slab

Before you even touch the concrete, you need to thoroughly clean the entire floor. Start by sweeping any large debris on the floor and then go over it with the vacuum.

You must clean any motor oil stains or other oil marks from the floor area. Use hot soapy water and a wire brush to clean the oil.

A commercial concrete oil stain remover will be handy if you encounter any stubborn stains. If they cannot be cleaned, consider using a grinder.

Oil stains stop concrete from adhering properly. You need to invest time in ensuring oil has been removed. 

Step Two: Mark Cracks and Shallow Dips 

Use a straightedge or a ruler to find any cracks, shallow dips, or low spots. Use a pencil to mark the damaged area that needs to be filled with concrete. 

Step Three: Grind Down High Edges

Grind, sand, and smooth the high edges around the damaged areas. Forcefully grind the edges with a grinder with a coarse grinding wheel.

Make sure you flatten areas around the cracks and dips where the floor has sagged. Use the grinder to remove oil stains that have not yet been cleaned.

Remember to vacuum the residue and grinding dust in the garage and the surrounding area. 

Step Four: Repair Cracks

You may need to use non-shrinking concrete patches to fill any holes. leveling cement will not fill deep depressions or cracks.

This step is very important if you have large defects in your concrete slabs. You need to fix low spots before you self level the concrete. 

You can purchase concrete patches in premixed tubs or a caulk gun. The caulk gun can be applied straight to the affected area through the tube.

You will need to use a steel trowel if you opt for the premixed tub.

Either way, make sure you force concrete patches into all crevices and corners of the low area. Once you’ve done this, spread the sealer evenly on top. 

Don’t expect the patches to finish the job. At most, it will only fill a 1 inch low spot. This is not enough to sort out your cracked, damaged floor. It may look like the problem has been solved, but this is only aesthetic. Giving up after this stage will result in structural damage down the line. 

You will need to leave the patches to dry for at least 24 hours before you proceed. The curing process is essential in creating a good base for the leveling compound. 

Step Five: Prime

After 24 hours, you will need to prime the area. Depending on what kind of leveling cement you use, you may need to brush a bonding liquid over the filled areas.

Note, this is not compulsory and is only required if specifically called for. If you do prime the cement, you will need to leave it for a few hours while it dries. 

Step Six: Mix Concrete 

Mix the concrete in a large, durable plastic bucket as per the instructions. If you’re making your own, generally a good concrete mix is four-two-one. Four parts rock, two parts sharp sand, and one part cement.

You will also need to add water and epoxy to the mix. Aim for a thick, pourable texture. Ensure you have enough mixture to cover the entire area. In most cases, concrete coverage rates are 0.03 to 0.04 pour per square foot. 

Step Seven: Apply the Concrete 

Apply the concrete mix to the area. Take time to slowly pour the concrete. You don’t want to move too quickly and drop all your concrete. It may be a good idea to ask someone to hold the bucket of concrete while you direct it over the depression or crack. 

Once you have poured the self leveling concrete, you will need to screed over the area until it is flat and smooth. You want to aim for a uniform, even surface without any bumps or dents. Finish off with a trowel to ensure the surface is pristine. 

You will need to do this as soon as you finish pouring the surrounding concrete. It will start to dry almost immediately and will be unable to be flattened.

To avoid this, screed and trowel right after you have poured the self leveling compound. 

Step Eight: Leave to Dry

After four hours you will be able to walk on the concrete. After 24 hours it will be completely dry. 

Step Nine: Apply Sealer or Paint 

Once the concrete has fully dried and is no longer damp, you can seal or paint the floor. It’s good practice to seal the entire floor.

Coating the floor in a sealer will prolong the life of the concrete, preserve its shiny appearance, and protect against stains and marks. Additionally, it will be easier to clean and maintain the concrete once it has been sealed. 

At this stage, you can also paint the concrete. Painting concrete is the best option for people who do not like the industrial, dark appearance of the material. Painting will also fill the surface pores of the concrete and create a more uniform colour.

If you want your concrete floor to seamlessly merge with your kitchen, bathroom, or living space, painting is the best option. Be warned, paint on concrete will chip over time. 

DIY Instructions for Cracks and Shallow Dips


And That’s How to Level a Garage Floor

And That’s How to Level a Garage Floor

Remember to call a professional to help with a large-scale leveling project. You don’t want to seriously damage your floor.

You have two options here. You can either opt for the more affordable (and traditional) mud jacking technique or,  the lighter version, polyurethane foam injections. Either way, you’ll have a perfectly levelled floor in no time. 

Small problems like cracks and low areas can be easily fixed without assistance. Always make informed, sensible choices when you’re DIY’ing. Otherwise, you could cause serious structural issues to your floor.

When in doubt, contact your local expert! Don’t take risks you know you’ll regret later. 

We hope this has been helpful! Best of luck on your floor-laying adventures!

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