Level the ground for Your New Metal Carport or Custom Metal Building

By Carport Central   |   Posted In: Installations

steel building structure

So, you’ve chosen a quality metal carport and picked out the perfect spot for it. What now? Whether you have purchased a metal carport kit or are planning on having it professionally installed, it’s important to level your site before the first pole is placed.

Why Leveling Your Site is Important

If your site is more than four inches or so out of level, you could be asking for trouble. Your carport could end up leaning to one end or one side. If not balanced, it could become top heavy, making it more susceptible to pulling up anchors during a severe windstorm. This could compromise not only your carport but also the contents within it as well. If you have a steel carport with an enclosure or another type of custom metal building structure, all components—roof panels, sides, and ends—need to line up properly or garage doors may not open properly. You are also inviting various animals (snakes, mice, and other critters) to find their way through the gaps into your enclosure.

Carport Base Options

Depending on what you will be using your carport, garage or storage shed for, you can go with a couple of options which are listed below:

Concrete Carport Foundation

A concrete slab has many benefits for your steel carport; unlike using a dirt floor or gravel, concrete does a better job of protecting your precious storage. For example, tires that sit in standing water or mud can suffer unnecessary wear and tear, which can become costly over time—especially if you are sheltering a larger vehicle. Concrete will keep your contents dry and clean.

Gravel Carport Foundation

This is a simple gravel base for the carport floor. Over time the gravel will shift and develop trenches which can be easily re-leveled; this is a more cost-effective option if you are on a tight budget or if you are sheltering items that don’t require as much TLC.

Check more about preparing your site for carport installation.

Carport - Concrete SlabCarport - Graveled Slab

How to Level an Area for Your Metal Carport

1- Check for Utility Lines and Clear the Area

Check with your local utility companies before you get started to make sure you don’t run into any gas or water lines. As soon as you are cleared, you can start by removing shrubs, grass, and other plants in the area.

2- Measure and Mark the Area

Using measuring tape, measure the area where you will be installing your metal carport. Be sure that the area you are measuring is slightly larger than the actual structure. Use a spray paint to mark the perimeter.

3- Place Stakes at All Four Corners

Place the ground stake in your first corner, then using a measuring tape to measure to the second corner, place the second stake. Repeat the process until all four corners are marked. If you are going to lay a concrete pad down, you will have to square your site. (We won’t cover squaring in this post, but instructions are readily available on the web.) Otherwise, if your site is well “squared,” you should be good to go.

4- Level the Sides with String or Twine

Once you have staked your four corners, find the stake that appears to be at the highest point. Measure a set number of inches from the ground and tie your string there. (We will use four inches for this example.) Choose your next stake and tie the string at the height where it seems to be level with the height of the first stake. Place a line or string level in the middle of your string and adjust the string on the second stake until the bubble in the sight glass of the level is in the middle.

5- Measure Your High/Low Points to Find the Difference

Once your string is level, measure the high point (which should be four inches) and your low point, and figure the difference. For example, if your string is four inches at one end and six inches at the other, you have a difference of two inches. This would be an acceptable slope for basic metal carport design. In the case of more complex steel carport plans, metal barns, or other metal buildings, however, you would need to add dirt to the low point or remove dirt from the high point to eliminate the slope so that your structure can be anchored securely. Repeat this step for the other three corners to be sure that your entire site is level. Now you are ready for your gravel or concrete.

How much does it cost to pour a concrete slab for a carport or metal building?

Ideally, pouring a concrete slab for a carport or metal building should be done by a certified professional.  The type of foundation chosen for a carport or metal building is dependent on the type of environment. Concrete is always a good foundation choice, but if you live in a rainy or moist area where the ground always stays damp, it might be hard to get concrete to set up properly.  In a situation like this, gravel would be a better match.

Check building codes

It is vital that you clarify what your local building codes are to determine the overall costs of placing a concrete slab. Your area might require special access or permits to pour a concrete carport slab or metal building slab.

To be safe, check with your state and local municipal authorities so they can tell you what steps to take according to their regulations. It is best to create site-specific drawings with details on the building materials and how the foundation will be built. These drawings would be approved by a state-licensed engineer.

Sizing of the concrete slab

The size of the concrete slab for the carport depends on the measurements of the carport chosen; the slab dimensions should align with those of the carport. The area marked for the concrete slab should also be somewhat larger than the actual building.

Type of slab or foundation

There are three types of slabs one can pick from including edge offset (which is the same measurement as the outer dimensions of the building with an additional 5 inches added), notched edge offset (like edge offset but the offset requirement is slightly less) and edge flush (the slab Is the same as outer building dimensions). All these slabs require footers at least 4 inches thick, and the footer width must be at least 12 inches.


Anchors for Carports – This can bring up the cost of placing a carport slab, depending on the type of anchors required such as rebar anchors or concrete anchors. Anchors must to be placed at least 4 inches into the slab.

Unlike gravel slabs or dirt floors, concrete slabs have multiple benefits that include providing a solid, raised surface for your car to park on – no more parking in mud or standing water. All things considered, a concrete slab is a great investment for a carport or metal building foundation.

By leveling your site prior to installation, you can avoid costly problems. Most installers will not install assemble your metal structure if the site is not reasonably level, requiring you to pay additional delivery and/or installation charges for a second trip out. Also, you could compromise your new metal structure by putting unnecessary pressure on one side or causing gaps which lead to a variety of other problems.

As an industry leader in custom metal buildings, Carport Central installs a wide range of durable, high-quality metal carports, metal garages, metal barns, RV carports, and other custom steel buildings. Contact us online or give one of our friendly building specialist a call at (980) 321-9898 to find the perfect metal building for your storage needs!

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