12×40 Lean to Patio Cover Plans

This step by step diy project is about 12×40 lean to patio cover plans. This lean to can be both used as a carport or as a patio cover. Take a look over the rest of my woodworking plans, if you want to get more building inspiration.

The 12×40 lean-to patio cover offers a spacious and versatile outdoor shelter, perfect for protecting your outdoor living space from sun, rain, or even for storing larger outdoor equipment. With its generous dimensions, it provides ample room for both relaxation and storage, making it a valuable addition to any home.

When buying the lumber, you should select the planks with great care, making sure they are straight and without any visible flaws (cracks, knots, twists, decay). Investing in cedar or other weather resistant lumber is a good idea, as it will pay off on the long run. Use a spirit level to plumb and align the components, before inserting the galvanized screws, otherwise the project won’t have a symmetrical look. If you have all the materials and tools required for the project, you could get the job done in about a day.

Projects made from these plans

12×40 Lean to Patio Cover Plans – PDF Download

Building-a-12×20-lean-to-patio-cover

Cut & Shopping List

• A – 4 pieces of 6×6 lumber – 76 3/4 long POSTS
• B – 2 pieces of 6×8 lumber – 173” long, 1 piece – 158 ¼”long TOP BEAMS
• C – 6 pieces of 6×6 lumber – 3 ft long BRACES
• D – 2 piece of 2×10 lumber – 12 ft long, 1 piece – 10 ft long, 1 piece – 8 ft long LEDGER BOARD
• E – 22 pieces of 2×10 lumber – 160″ long RAFTERS
• F – 24 pieces of 1×4 lumber – 12 ft long, 8 pieces – 6 ft long PURLINS
• G – 2 piece of 1×6 lumber – 12 ft long, 1 piece – 10 ft long, 3 pieces – 96” long, 2 pieces – 66 ½” TRIMS

• UNLOCK SHOPPING LIST

Tools

 Hammer, Tape measure, Framing square, Level

 Miter saw, Drill machinery, Screwdriver, Sander

 Concrete mixer, Post hole digger

 Safety Gloves, Safety Glasses

Time

One week

Related

• Flat roof carport plans
• Lean to carport plans
• 20×24 Patio cover plans

Building an attached carport – 14×20 DIY Plans

12×40-Attached-Carport—layout

The first step of the project is to set the 6×6 posts for the wooden attached carport. Use batter boards and string to layout the posts for the 12×40 carport. After laying out the posts, measure the diagonals and make adjustments until they are perfectly equal.

Anchoring the posts of the anchor

You can set the posts in concrete or you can pour 3′ deep footings and use posts anchors. Considering this is a light outdoor project, you can set the posts to anchors. That is why, these plans are designed having that assumption in mind (concrete anchors).

Dig the holes and set the 14″ tube forms. Fill the tubes with concrete and set the post anchors. Make sure you let the concrete to dry out for a few day, before installing the posts into place. Use temporarily braces to secure the posts until you attach the plates.

Installing the posts

Use a laser level / water level to make sure the top of the posts are at the same level.

Top-plates

Post-to-beam-connector

Continue the project by attaching the 6×8 support beams to the top of the posts. See the 12″ overhangs on the sides. Plumb the posts and make sure the beams are horizontal. Use post to beam connectors to secure the beams to the top of the posts. Insert 1 1/2″ structural screws to lock the connectors into place.

Fitting-the-braces

Braces—detail

Use 6×6 lumber for the braces. Make 45 degree cuts at both ends of the braces and then secure them into place with 5 1/2″ screws (at least 2 screws for joint).

Fitting-the-ledger-boards

Height-for–ridge-beam

Next, we need to attach the 2×10 ledger to the house. Make sure you set the 2×10 ledger directly into the framing structure with 4 1/2″ lag screws with washers (or longer, depending to the house structure). Use a spirit level to check if the ledger is horizontal.

Drill pilot holes and insert the screws to lock it into place tightly (see your local codes for more info on how to secure the ledger). Insert 3 screws into each stud.

Building the lean to roof

Rafters

Rafter-detail

Use 2×10 lumber for the rafters. Make a 7 degree cut to one end of the rafters. Mark the cut lines on the beams and then get the job done with a circular saw. Smooth the edges with sandpaper.

Fitting-the-rafters

Rafter-ties

Fit the rafters to the attached carport, every 24″ on center. Fit the rafters to the ledger beams using rafter hangers and 1 1/2″ structural screws. Use rafter ties and 1 1/2″ structural screws to lock the rafters to the support beams.

Fitting-the-hangers

To attach rafters with rafter hangers, first, position the hangers along the support beams at the desired spacing, ensuring they are level and aligned. Next, place the rafters into the hangers, making sure they fit snugly, and then secure them with appropriate nails or screws to create a sturdy and reliable patio cover structure.

Fitting-the-purlins

Fit the 1×4 purlins to the top of the patio cover. Place the purlins every 24″ on center and secure them to the rafters with 2 1/2″ screws. We need these purlins so we can install the metal roofing sheets.

Front-trims

Side-roof-trims

Use 1×6 lumber for the roof trims. Align the edges flush and insert 2″ nails to lock them into place. Cut and fit the trims to the sides of the carport. See the 7 degree cut to one end.

Installing-the-roof-flashing

In addition, install a flashing at the intersection of the roof to the wall. The flashing will waterproof the joint and prevent water leaks. Make sure you ask directions from the roof manufacturer, so you use the best solution to seal the wall to roof joint (see if it’s installed under or over the roof sheets).

Start by measuring the area where the flashing will be installed and cut the metal flashing to the appropriate size using tin snips or a metal cutting tool. Clean the surface where the flashing will be attached and ensure it is dry and free of debris. Apply a layer of construction adhesive to the back of the flashing and press it firmly against the wall, aligning it with the desired position. Secure the flashing in place with galvanized nails or screws, ensuring they are evenly spaced and driven flush with the surface.

Finally, inspect the installation for any gaps or loose sections, making any necessary adjustments. With careful attention to detail and adherence to safety precautions, you’ll successfully install metal wall flashing to provide protection and enhance the durability of your walls.

Finishing touches – Patio Cover

12×40 Attached Carport – dimensions

Installing metal roof sheets as a beginner involves several important steps. First, prepare the roof surface by ensuring it is clean and free of any debris. It’s also necessary to install an underlayment to provide a moisture barrier and improve insulation. Next, accurately measure and cut the metal sheets to fit the roof dimensions using tin snips or a metal cutting tool.

When attaching the sheets, start at one corner of the roof and align the first sheet with the edge. Secure it using roofing screws with rubber washers, spacing them appropriately along the edges and center.

Repeat this process for the remaining sheets, overlapping each one by about 2 inches to ensure proper water drainage. Finally, carefully inspect the installation for any loose screws or gaps, making any necessary adjustments. It’s crucial to prioritize safety by following guidelines, wearing protective gear, and seeking professional help if needed.

12×40 Attached Carport MOP

Last but not last, you need to take care of the finishing touches. Fill the holes with wood putty and let it dry for several hours. Smooth the surface with 120-220 grit sandpaper and apply a few coats of stain to enhance the natural look of lumber and to protect the components from the elements.

12×40 Attached Carport – side view

A 12×40 lean-to patio cover provides a versatile outdoor space that can be tailored to various purposes. Whether you’re looking to enhance your outdoor living experience or maximize the functionality of your yard, there are plenty of ways to utilize this ample shelter.

For those who love dining al fresco, consider transforming the space into an outdoor dining area with a large table and chairs, perfect for family meals or entertaining guests. If relaxation is a top priority, outfit the patio cover with comfortable outdoor furniture like sofas and lounge chairs, creating a cozy oasis for unwinding.

If you find yourself working from home, why not set up an open-air workspace where you can enjoy fresh air and natural light? This arrangement can be equally useful for creative endeavors, making it an inspiring art studio.

Families with children can turn the space into a shaded play area with toys and games, while garden enthusiasts may use it for potting plants, storing gardening tools, or simply as a sheltered area for tending to their garden. Storage is another option, with the lean-to serving as a convenient spot for bicycles, gardening equipment, or even as a makeshift garage for motorcycles or small vehicles.

12×40 Attached Carport – front view

Fitness can create an outdoor gym, artfully integrating exercise equipment. Likewise, a hot tub or spa can be installed for a relaxing soak under the cover. For those who enjoy outdoor entertaining, consider setting up an outdoor bar area with stools and a refrigerator.

With its generous dimensions and sheltered environment, a 12×40 lean-to patio cover offers countless opportunities to enhance your outdoor living space and tailor it to your unique needs and preferences.

If you build this carport attached to the double garage, you will have a nice shaded area that will be perfect for a car or for woodworking outside. If you want to get the Premium Plans, see the GET PDF PLANS button bellow.

This woodworking project was about 12×40 attached patio cover plans. If you want to see more outdoor plans, check out the rest of our step by step projects and follow the instructions to obtain a professional result.

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