Maybe you have amazing dreams of building a garage – gaining space for seasonal storage, outdoor gear, and of course, your vehicles.
But reality hits: you need a budget. And you’ve arrived at this question: How much will it cost me to lay a garage foundation?
In this article, Site Prep explains the total estimated cost of a garage foundation, as well as outlines the other aspects that can contribute to the overall cost. And if you’re in need of a quality, durable foundation for your garage, get a free quote.
Alright, let’s get some pricing answers!
Table of Contents
How much do garage foundations cost?
In reality, garage foundation costs vary considerably. Nationally, the cost for a garage foundation can range from $5 to $35 per square foot.
Let’s take a look at the average prices in a few Eastern states:
| State | Price per square foot |
| Pennsylvania | $18-$26 |
| Maryland | $27-$35 |
| New Jersey | $27-$35 |
| New York | $27-$35 |
Factors influencing garage foundation costs
You viewed the average cost per square footage, but there are other things to keep in mind when figuring out the cost of a concrete foundation for a garage. This includes:
- Garage Size and Weight
- Soil Type
- Site Preparation
- Climate Considerations
- Permits
- Lot Coverage Regulations
- Slopes and/or Hills
Okay, let’s dig deeper into each factor!
Garage Size and Weight
Size and weight affect the overall cost of a concrete pad for garages. For each additional car, your garage is gaining square footage and weight, which will require a larger foundation (and greater costs). And it goes without saying, that the larger the garage, the heavier. Plus, it’s good to keep in mind the items that you will be storing inside the garage. Will it be mainly Christmas decorations and bikes? Or do you plan to add heavy equipment like tractors?
Soil Type
The soil type beneath your concrete foundation is a critical consideration when thinking of overall costs. When adding a concrete foundation, sandy soil can pose challenges. As contractors start to dig sandy soil, the walls often fall in, which requires more concrete to be poured (and a higher price, overall).
If your soil is soft or not suitable for compaction, contractors remove that soil until they get to firm soil. At that point, they will fill it back up with stone which adds additional costs.
Site Preparation
Where are you planning to build your garage? Are there any trees, stones, rocks, bricks, blocks, small bushes, stumps larger than ten inches, or other obstructing objects in the way? The good news is a contractor can remove everything with an excavator! But it may come at a greater overall price for your garage foundation. However, if you have access to an excavator, you can remove them yourself and save a bit of cash.
Climate Consideration
Are you planning to lay a foundation while there’s frost? If you answered “yes,” you will find the overall cost of your garage slab foundation will increase. Why? When frost is present, you have to excavate footings well below the frost line. This takes more time, leading to higher costs for the concrete pad for your garage.
Permits
No one wants to have delays in their building process! Depending on your local jurisdiction, you may have to acquire permits before you begin laying the foundation for your garage. In that case, it’s best to start the permit process sooner rather than later. Although permit fees can vary significantly, many jurisdictions charge based on the estimated cost of construction. For example, if you estimate your project will cost $15,000 and the township charges a 1% fee, you’ll pay a total of $150.
Lot Coverage Regulations
Some jurisdictions have “lot coverage” regulations. This means there are potential limits on how much of your property can be covered by buildings. Like permits, it’s imperative to be aware of these restrictions before drawing up the size of your garage. Certainly, you don’t want any bad surprises after you pour your concrete foundation!
Slope or Hills
When planning to add a garage on a slope or a hill, the cost of your garage foundation will increase because of extra reinforcements and labor. Look at the following graph to get an estimate of the extra costs you may incur; the exact price will be available after your contractor does a site visit.
| Slope/Hill Off Level | Approximate Price Increase |
| 10” to 15” | 10% |
| 16” to 20” | 20% |
| 21” to 25” | 30-40% |
| 26” to 40” | 30-70% |
How much will it cost to lay my own garage foundation?
To lay your own garage foundation, you will need three main materials: blocks ($2-$5 a piece), stones ($20-$50 per ton), and concrete ($160-$250 per yard). The total cost for your garage foundation will really depend on the size of your garage and the overall weight of the structure and materials you plan to put in the garage.
But before you get too excited to begin constructing your own garage foundation, please heed our professional advice:
1. If you don’t have experience with foundations, don’t even try.
Yes, it’s that simple. One, this process is a lot of work. Two, if you don’t get the foundation level and square, your entire garage will not be supported. What’s the point of going through the hassle if your garage can’t be supported on its foundation? Let the experts do what they do best…especially if you plan to add a concrete foundation (they require more expertise than stone foundations).
2. For garage walls seven feet high in the back, seek professional contractors
What does this mean? If you’re at the front of the garage looking at the back and your grade drops off more than seven feet, you need to use a poured wall (or other foundation reinforcements) instead of just blocks. This whole process is complicated. If done incorrectly, the foundation can bust under the weight of the garage.
3. If you do have experience with foundations, read our pro advice:
- Check your township requirements for footing depths
- Ensure you have the experience to dig footers
- Have the proper leveling equipment to make sure the footers and block are level
- Ensure you pour the concrete slab properly
- Personal experience finishing concrete before starting on the floor is a must
How can I cut down the cost of my garage foundation?
We get it. You’re on a budget, trying to work out a way to move forward without incurring more expenses. While there are a few ways to cut down on prices – smaller footers, smaller blocks, foundations without stones, and reduced floor thickness – these price reductions can come with some negative side effects.
That’s why we always recommend sticking with quality…But you can cut down costs for a professional to add your garage foundation! Here’s the trick: bid, bid, bid! And check in with multiple companies.
Smaller Block: 6” Block Versus 8” Block
Before you decide to go with this option, you will need to check with your township to ensure that this is a legal alternative for you. The drawback of this decision is that you’ll have much less strength for the structure of your garage.
Smaller Footer
Typically, a footer is 8” thick and 20” wide. If you’re looking to save some money on your garage foundation, you could opt for a footer that is 8” thick and 16” wide. But keep in mind that your foundation is more likely to settle. Additionally, this smaller footer can become an issue since the weight of your garage will be supported by a smaller footprint.
Smaller Block: 6” Block Versus 8” Block
Before you decide to go with this option, you will need to check with your township to ensure that this is a legal alternative for you. The drawback of this decision is that you’ll have much less strength for the structure of your garage.
Smaller Footer
Typically, a footer is 8” thick and 20” wide. If you’re looking to save some money on your garage foundation, you could opt for a footer that is 8” thick and 16” wide. But keep in mind that your foundation is more likely to settle. Additionally, this smaller footer can become an issue since the weight of your garage will be supported by a smaller footprint.
Foundation Without Stone
This is yet another way to save on the cost of your concrete foundation for a garage, but comes with this risk: your concrete slab can move quicker and may crack easier.
Reduce the Floor Thickness
To reduce the cost of your garage foundation, you can cut down on the thickness of your floor – change it from 4” to 3” thick. But this “solution,” weakens the overall strength of your garage foundation.
Quality
While you may have the skill set to do it yourself, hiring a professional ensures you will have a quality foundation, leading to a quality garage. Maybe this isn’t what you wanted to hear. Your wallet may be sighing under a load of pain. But quality doesn’t have to mean expensive! Check in with many different companies. Bid on the project, and let each company know that you have multiple bids out there. And…
Never Settle
It can be tempting to save a few dollars here or there. But don’t forget how important the foundation is to the structural integrity of your garage. Ultimately, you are making an investment in your real estate with great returns and don’t want to be too cheap on the overall cost of the concrete foundation for your garage.
Wrapping It Up
Hopefully, you received the answers you need regarding the cost of garage slab foundations! If you have any more questions, feel free to contact us at Site Prep or request a sheet with sample foundation prices. Also, if you want to know the cost for shed site prep, take a look at our article.
Well, that’s all for now! May all your garage dreams be achieved!