Interior view of the wooden roof and horizontal support beams of a carport under construction.

How to Build a Carport

If you have at least one vehicle — or even any amount of items — that you’d like to store outside, a carport is a great solution. Not only are carports inexpensive, but they are a relatively safe and easy DIY project. Compared to building a garage, carports have several advantages. 

They add value to your home with little overhead costs. They protect your cars and possessions from the elements — such as wind, rain, snow, and sun. Furthermore, carports are versatile. If you want to convert the structure to an outdoor living space, you can do so. However, to make your carport project run seamlessly you have to prepare thoroughly before beginning the job. 

1) Make Your Plans

Although carports are arguably easy to construct, you will still need to formulate plans in advance of any work. First, decide what materials you want to use. Immovable carports are generally made up of wood or metal. Metals like metal are solid choices for carports, providing quick completion and increased longevity. Wooden construction, however, may lend to more aesthetically pleasing designs. From there:

  • Determine the right-size carport for your needs; 
  • Outline your budget;
  • Choose your design carefully, considering local weather; 
  • Decide where to place the structure, evaluating any power, gas, or plumbing lines and trees nearby;
  • Map out your current gutter system, and plan one for your carport that can coexist;
  • Create a rough sketch of your end goal;
  • Look into any restrictions on building from your homeowners’ association or local legislature.

You don’t have to be an architect to construct a carport. However, making preparations before any level of construction project will help you avoid any mishaps along the way. 

2) Gather Your Supplies

Once you’ve hashed out your plan, you should make a list of the tools needed to execute it. Some supplies to consider include: 

  • Dust masks; 
  • Hardhats;
  • Earplugs;
  • Goggles;
  • Concrete mix; 
  • Buckets; 
  • Frame materials;
  • Ladders; 
  • Tape measure;
  • Shovel; 
  • Hammer and nails; 
  • Power tools. 

This isn’t an all-inclusive list, as your supplies will vary depending on the nature of your project. For instance, if the plot of land you are building on is particularly stubborn, you may need more invasive tools. 

3) Prep the Ground

The ground should already be evaluated to see if it is suitable for holding the weight of a carport and its basic foundation. Then, you have to prep the ground for the concrete slab that typically goes at the base of the carport. This preparation includes, but is not limited to: 

  • Leveling the ground; 
  • Creating a slight slope for water runoff; 
  • Ensuring proper soil moisture;
  • Mapping out joint placement;
  • Properly pouring the concrete slab.

While it’s possible to have soil, asphalt, or gravel at the base of your carport, concrete is the preferred option. It requires less maintenance and provides the stability required to hold your heaviest items, like cars and boats. Pour the concrete — possibly with the help of a professional — with room to spare for posts to be affixed on the outside.

4) Dig Holes for Your Posts

The holes for the carport posts should be aligned so that the frame is at least one foot shorter than the roof. This prevents water from collecting under your structure’s base, causing integrity issues. Measure up to 24 inches inward from where the projected roof will jut out. Typically, you will need to mark out spots for two posts for an attached carport and four or more for a freestanding structure. 

To dig the holes, you will first need to drive stakes into the ground at each marking. Then, use string and a carpenter square to determine that each stake is at a 45-degree angle with its nearest outside stake. After this, dig holes with either a shovel or an auger drill for more stubborn soil. The holes should be about one foot in diameter and two feet deep — with no loose soil at the bottom that could later shift and sink.

5) Pour Concrete Into Holes and Place Your Posts

Once you have your post holes ready, pour prepared concrete into them with about two inches of room left at the top. This part is time-sensitive, so make sure your posts are ready to be inserted into the wet concrete. They should already be pre-measured and cut for the most part, but you can trim the tops once planted. Stick the posts into the holes before the concrete is set, and use a level or plumb bob to ensure that they are all flat and aligned correctly. 

The concrete affixing the posts will be set in roughly 48 hours. After this, you can trim the posts to your liking — typically about 77 inches from the ground. It’s also wise to brace the posts with removable stakes or two-by-four boards. 

6) Attach Beams and Rafters

Check the angles and alignment of your posts one more time before starting to attach beams and rafters. This usually involves constructing a frame of perimeter beams and connecting them with rafter planks. Before lifting the planks, mark out the location of each rafter connection on the beams. You’ll want this to allow the rafters to be flush with the beams while still being able to tilt, allowing for water to flow easily off the planks after construction. 

Pre-drill holes and gather some batten screws. Don’t forget to include holes for attaching the perimeter beams to the posts. Using your construction-specific safety equipment, ladder, and ideally the help of another person, screw the batten screws in the predetermined spots. 

7) Construct the Roof

Whichever roof material you’ve decided to go with, it’s now time to add it to the existing frame. If you are constructing it from wood, this will take some extra time and preparation on the ground. The more intricate the design, as well, the more beams and rafters will need to be placed beforehand. For instance, a gabled roof requires a triangle shape from your frame. 

A metal roof will have a few more advanced requirements, but there will usually be fewer parts to assemble and less overall maintenance. Make sure to match the metal of your flashing to the metal of the roof to avoid any corrosion issues. 

Regardless of roof type, waterproofing the frame and roof is also imperative. Often, you can add underlayment that comes in the form of waterproof felt. This should be applied underneath the roofing and periodically checked for damage and tears. 

Attach the roof to the existing frame with the appropriate tools. Use the correct screws for each material — wood screws for wood, metal for metal, etc. — to preserve the integrity of the structure. 

8) Affix the Gutters

Gutters are necessary to further draw water away from your carport structure. The slope you created earlier when preparing the ground will give you a guideline to determine the length of material that you need. Generally, you will need 35 or fewer feet of material — vinyl or galvanized metal — for a carport project. Gutters come in all different materials and designs and are attached to the lip of your carport roof, draining away rainwater and debris. 

When constructing the gutter system, you will want to create angles for every 10 feet of gutter. Use chalk to outline the proposed gutter system before attempting to affix it to the roof. This way, you will ensure proper installation and drainage. Then, focus on attaching the gutter system to the carport roof with hangers every two feet. 

Once the gutter system is firmly attached, use screws to attach the downspout where you want the water to drain away from the carport and any adjacent buildings. It’s important to assemble the pipes on the ground before attempting to hang them on the roof. Research the ins and outs of how a gutter system works to build this most effectively.

9) Put on the Finishing Touches

Your job could end here, or you could continue the fun with some carport customizations. There’s no deadline on when to add extra features, but make sure to do so when inspiration strikes. The flexibility of a carport will allow you to add on to it later, but you may want to spruce it up while you have all of the tools out and available. Some ideas for finishing touches include: 

  • Blinds and curtains; 
  • Siding and shutters; 
  • Outdoor furniture; 
  • Lighting fixtures; 
  • Paint. 

Go wherever your creativity takes you. Once your carport is constructed, you can happily move in items to be stored underneath. The low-maintenance nature of these structures allows you to only check on them when you notice leaks or cracks. If the construction project is properly planned and executed, you will now be able to enjoy your carport and its many uses for years to come.