A garage can offer plenty of utility when it comes to storage, working, or a place to park your vehicles. So it stands to reason that adding a garage to your property can increase the value and appeal of your home.
However, building a garage does require a sizable investment as the materials and labor are similar to home construction in many ways.
One of the first things to consider when building a garage is the foundation and there are several options here, each with its own benefits and costs.
Below, we’ll break down the costs of a garage foundation as both a DIY project and with installation. We’ll also look at which type of foundation might be right for your property as well as the pros and cons of each type.
Types Of Garage Foundation
All foundations are not equal and much of the choice will come down to the climate where you live as well as the soil composition on your property. Finally, how large your garage is going to be will also play a role in the foundation types that are available.
Gravel Pad Foundation: $5 – $10 Per Square Foot Installed
DIY materials cost – $1.40 to $1.85 per square foot
This is the cheapest option and works for an unattached garage. It also only works for smaller garages.
In general, these will be 4 inches to 6 inches deep and can provide decent drainage as well.
Your soil type needs to support this type of foundation so they may not work everywhere. Also, many cities have restrictions on foundation materials, so a gravel pad may not be sufficient to meet building codes in your area.
Floating Concrete Foundation: $8 – $14 Per Square Foot
DIY materials cost – $5 – $6 per square foot
Next up is the floating concrete slab. This foundation can be used for larger garages and is a great option if your climate and soil support it.
These are only appropriate for mild climates without regular freezing.
Slabs don’t require deep footer trenches either, so the overall cost can be lower for a slab installation. This makes it a good alternative to gravel if you want to save money yet still have the benefits of concrete.
Monolithic Concrete Foundation: $10 -$16 Per Square Foot
DIY materials cost – $5 – $8 per square foot
As the name suggests, a monolithic foundation is in one giant unit and is poured all at once. In construction, this is the fastest and most efficient way to put down a concrete foundation. So of course, this is a very popular type of foundation as time is money when it comes to construction of any kind.
These do require extremely flat ground though as they are prone to cracking. So if your property needs a lot of fill or recently had fill that isn’t fully compacted, this may not be a good option.
They are also generally not recommended for areas prone to flooding, once again due to the cracking issues.
Concrete Block Foundation: $10 – $15 Per Square Foot
DIY materials cost – $6 – $9 per square foot
These are priced similarly to a monolithic foundation, so the per-square-foot-cost is the same, but construction may be more time-consuming resulting in a higher overall cost.
A downside of these is they can be prone to leaking and therefore water damage. So they may not be the best option in extremely damp climates with lots of rainfall.
Lateral strength can also be lower with concrete block foundations, although this can be solved by using the right amount of rebar.
Other Costs Of A Foundation
If you’re replacing an old garage, there may be additional costs to remove the old foundation. This can generally run between $800 to $1500 extra. Although, there may be cost savings as well if the ground is already prepared for a similarly sized structure.
If pouring concrete, you may need a pumper truck as well to reach the site. This will have costs depending on the situation.
If this is a fully DIY project, you’ll likely want a skid steer or bobcat at the very least. Make sure to get a bucket with teeth when renting. These will run about $200 for the day.
Finally, coatings for the concrete floor within the garage can run as low as $0.10 per square foot for basic sealants if you do the work yourself. More advanced or decorative coatings like epoxy or urethane can run about $2 per square foot for all materials and $5 to $10 installed.
Building Codes
Many areas will have specific building requirements for foundations used for homes as well as structures like garages. Although a small enough garage may fall into the category of a shed.
Make sure to check with your local agencies to learn what foundations are allowed for the type of garage you want to build.
Overview Of Garage Foundation Costs
As you can see, there are several options available when building a garage foundation and they each have their strengths and weaknesses. But when paired with the right soil and climate, they all can work well.