How Thick Should a Garage Floor Be?

Learn how thick your garage floor should be to withstand the weight of a car

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If you decided to get your garage a concrete floor, then you have definitely already faced this issue: what should the garage floor thickness be? SInce your garage flooring should be strong and durable enough to be able to withstand the weight of a car (or two cars, for example), it is important to calculate its thickness in advance before the contractor starts working.

In this article, you will be able to find the answer to this question. We are going to tell you about the needed concrete thickness for a garage floor, as well as the types of concrete that might be suitable for your particular garage floor depending on the purpose of its use. Also, you will learn what tools you will need for getting a garage concrete floor, and also, we will explain what things should be taken into consideration when getting ready for the concrete to be poured.

Like this, you will be able to figure out exactly not only how thick your new concrete garage floor should be, but also, you will know for sure that you have considered all the possible nuances, and now you have nothing to worry about.

Beautiful empty garage floor

Garage Floor Concrete Thickness

So, you might be wondering, how thick my concrete garage floor should be? Typically, around six inches is the ideal thickness for a concrete garage or driveway. This thickness should be enough to withstand the weight of many mid-sized cars and even some heavier vehicles. However, some garages may only require four inches of concrete, while others may need more, sometimes up to nine inches, depending on the weight they are going to bear.

If you are about to make a new concrete garage floor, then you are definitely concerned about the thickness of your future floor! Since contractor work costs a lot (because the foundation will be pretty pricey even without having to replace it), you might want to do all the calculations and measurements in advance to know for sure how things should be done.

Before you start pouring new concrete, you need to consider how heavy your car or cars are that are going to be kept in a garage. If all the vehicles that will be kept there are of the same weight, then it will be clear what thickness of floor you might need. 

However, if one of the cars is lightweight and another is heavier, for example, then you’d better pour a thicker layer of concrete at once! Like this, your garage floor will surely be able to hold the weight of both vehicles easily.

What Tools You Might Need For Pouring a New Concrete Floor

Like any home renovation project, pouring a concrete garage floor requires the use of certain tools in order to do everything right. Without proper tools, there can not be any construction work done. 

If you are going to hire professional contractors to come, and do the job for you, then you don’t have to worry about the tools since professionals will bring everything with them. However, if  you are going to pour concrete yourself, you should be aware of what tools you will need. 

Below, we have listed the most essential tools you are going to need in order to make the garage floor.

  1. Pressure washer
  2. magnesium float
  3. Safety goggles
  4. Concrete edger
  5. Finishing trowel

It is a good idea to check whether or not you have all of them in your disposal already before you start working with concrete. Like this, you will not find yourself in the middle of the concrete pouring process lacking one of the tools that you need badly right now!

So we suggest you double check your tool box and if you lack something, better go purchase it in advance. The better you are prepared, the less stress you will have during the work.

What Types Of Concrete Are There For a Garage Floor?

There are various types of concrete out there, as you probably know. And if you want to pour a concrete floor in your garage, you might be wondering what type of concrete  exactly is needed for this purpose. This question becomes even more important to figure out if you are not very knowledgeable about the types of concrete.

As all of us know perfectly well, your garage is going to be used for heavy-duty work. This is why it needs to be healthy. There are three types of garage concrete that you can find more comfortable. Those are the following:

  • Light Burdens. The concrete should be at least four inches thick for one or two light cars or trucks.
  • Medium Burdens. The concrete needs to be six inches thick if the garage is going to be used for average-sized vehicles and medium to large trucks.
  • Heavy Burdens. If there is continuous traffic from heavy vehicles on your garage floor, it is recommended to put concrete that is between six and eight inches thick. The floor must also be appropriately managed and secured so that heavy loads, such as large trucks, do not cause the concrete to crumble.

The more clearly you define what type of burden your garage floor usually has, the more correct your choice of concrete is going to be. This will affect the time of service of the garage floor and its state during the use, so make sure that you take all the nuances into consideration before making a final choice!

Things to Consider Before Pouring New Concrete

So, you have figured out how much weight your garage floor is going to carry regularly, and you have also defined what type of concrete you will need for pouring. You have all the tools that will be needed for the concrete pouring process, or you might hire the professional contractor. Basically, you are ready to start.

Now that all the preparations are completed, it is time to learn about a few factors and nuances that need to be taken into consideration for a garage concrete thickness. We recommend you go through them carefully, as they are susceptible.

How Big Is Your Garage Going To Be?

This is an important thing to keep in mind as you plan your pour-out for various purposes. Your garage’s size will be determined by the maximum amount of stuff stored in it. 

Building codes used to stipulate that four inches lower than the house’s floor level is the attached garage floor. The reason for needing this small move was that spilt fuel, gasoline vapors, and carbon monoxide would be blocked from getting into the building. 

Nevertheless, this particular nuance is not included in a current residential building code. As a result, it means that an entire house including the enclosed garage can be set on a concrete slab that is poured at one height.

What’s Your Budget?

There are two extra inches of concrete may not seem like much, but it can reflect many tons of material. This implies that the cost difference between a four-inch floor and a six-inch floor can be far higher than you expect.

Concrete garage slabs probably cost approximately $6 per square foot, or $4 to $8 per square foot, including labor, which is around $5,400 for a standard 30-by-30-foot slab that’s 6 meters wide, or between $3,600 and $7,200. It costs around $4 per cubic foot.

So in case you are in search of a way to save some cash, and if you are sure that you are not going to use your garage for too heavy vehicles, it might make sense to go for a slightly less dense floor. However, if you need to use this space for overloaded cars, the additional investment will certainly be worth it.

Where Are Your Doors Positioned?

This is the factor that needs to be considered if you are pouring concrete in a garage that is already built enough to have doors. You could block the exit from your house to your garage if your floors are too thick, making it difficult for you to open it.

This is an undesirable spot to be in since even a little bit of moving a doorway can be a huge hassle. It’s a lot easier to prepare ahead so that none of your doors needs to be changed.

How Thick Does a Concrete Slab Need to Be For a Garage? 

A standard garage slab thickness should be at least four inches deep. However, you can make the thickness up to six inches in case your garage is going to be used for the heavy trucks or other vehicles. Building codes provide conditions that differ by area for the concrete mix, so consider this nuance. 

Do You Need a Good Base?

The foundation’s ability to provide ongoing support is much more critical than the ability to deliver performance. If one dimension settles longer than another, the slab can bend and crack as a result.

The best solution in this case would be to remove the top layer of soil and put over the subsoil a minimum four inch thick layer of compactable gravel or crushed stone. That would serve as a surface. 

Does Fiber Reinforcement Use For Better Garage Floors?

For a wide range of industrial and commercial projects, concrete floors have a sleek look and exceptional durability. And if you want your concrete floor to be made more long lasting and durable, consider adding reinforcement.

 A small piece of material with reinforcing properties is fiber. It is these reinforcing properties that give structural integrity to the fibrous material. There are various types of fiber reinforcement. Like: Organic fibers, carbon fibers, steel fibers, glass fibers.

When using reinforcement, you need to remember that the finished surface might usually look a little “hairy” in case striking off is done manually, and it wears off with traffic rapidly.

Expansion Joints

When temperature and humidity wax and wane over the year, some materials may shrink and expand. The same thing happens with concrete as well. That is why, around the edges of the concrete garage floor as well as around posts or other protrusions in the slab, expansion joints must be included.

Expansion joints are joints separating one concrete slab from another which may be at least 1″ or 2″ wide. 

Finishing And Curing

When pouring concrete, you should keep in mind that it needs to be leveled and smoothed before the rest of it is poured. It is best, then, to leave the new slab alone.

At this point, it is good to keep in mind that concrete does not actually dry out. Instead, a chemical curing process takes place, and as a result, a stable, dry mass is produced. When the curing process is in progress, the top layer usually needs to stay wet. And in order to bring down evaporation, contractors spray the curing compound frequently on top of the slab. As an option, they can cover it with sheeting. 

So, now you know how thick a layer of new concrete should be in your garage in order to be able to withstand any vehicle that is going to be kept there. We told you what types of concrete are best to be used for this purpose, and also, why you should take the concrete layer thickness into consideration before you start pouring it. 

And since now you also know what additional factors and nuances have to be taken into consideration before you or your contractors start working on your garage floor, you will surely be able to complete this project both quickly and effectively!

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