Build a Simple Carport Next to Your Garage

By James Dulley

March 2, 2017 4 min read

Dear James: Our mother just moved in with us, so we could use a carport. There is room next to our garage. What is a simple, low-cost carport design we can build? — Samantha T.

Dear Samantha: Building a carport is a great idea, especially if you have family visiting for extended periods. In addition to protecting the car from the weather, when the car is being used, the carport can double as a covered play area or work area. If you are really into efficiency, you can use it to hang clothes to dry after washing.

Carports are particularly easy to build because the sides are open. The building codes for unenclosed additions are often less strict than for enclosed rooms. You may also have more flexibility on where you can locate it on your lot. Make sure to check your local building codes and zoning first.

One of the simplest carport designs uses a slightly sloped ledger plate attached to the side of the garage and vertical wooden posts along the other side. Once the basic structure is completed, the top can be covered with any roofing material. Corrugated PVC sheeting is an easy-to-use material and it is durable.

In most climates, run the roof corrugations parallel to the garage wall so water runs off the end which is sloped down. Install a gutter and downspout on that end so the car does not get splashed as water runs off. In areas with heavy snow, use a non-corrugated roof and slope it down away from the garage wall.

The basic construction method is similar to building a deck, except the carport is higher from the ground. Attach a 2x10 ledger plate to the side of the garage to support the roof. Use masonry bolts if you are attaching it to brick or blocks. If the side of the garage has siding, cut away part of the siding so the ledger rests against the sheathing. Bolt it to the wall studs.

Install vertical posts, probably three for the typical carport length, to support the other side of the roof. Dig holes deeper than the frost line and taper them wider at the bottom for stability. Set the posts in the holes and fill them with concrete. Leave a concrete crown on the top so water does not puddle around the posts.

If you are placing the posts over a concrete floor or patio area, use fence post support sockets. These are square metal sockets with a wide base. The base is screwed down to the existing concrete floor. Standard posts should slide snugly into the sockets and then they are screwed in place. Attach another ledger across the posts to tie them together.

Run joists from the ledger on the garage wall to the one on the outer posts to create the structure for the roof. Follow local codes for sizing and spacing the roofing joists. You can get fancy and notch them, but using galvanized joist hangers is easier.

Lay the corrugated roofing over the joists overlapping joints at least two inches between pieces. Drill clearance holes through the roofing and screw it to the joists using self-sealing washers under the screw heads.

Send your questions to Here's How, 6906 Royalgreen Dr., Cincinnati, OH 45244 or visit To find out more about James Dulley and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at

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