Building a Lean-to Shed

Building an attached shed can be a great way to expand your storage space while keeping your property organized and clutter-free. Whether you're looking to store gardening tools, seasonal items, or landscaping supplies, an attached shed can help you stay organized and make the most of your available space. This article will guide you through the basics of building an attached storage shed, from planning and design to construction and finishing touches.

Plan and Design Your Shed

Before you start building, it’s essential to have a clear plan. Take into account the purpose of the shed, the available space, and any local building codes or regulations.

Assess the Space: The shed can be attached to an existing structure like your garage or house. Make sure the site is level, dry, with no drainage issues and that there’s enough room for easy access to the items you plan to store.

Size: Common sizes for attached storage sheds range from 6x8 feet to 10x12 feet, but you can tailor the dimensions to fit your needs.

Design: Create a simple sketch or blueprint of your shed. Typically the finished appearance is designed to complement the existing structure. Make sure to plan for a door, windows (optional), and proper ventilation to avoid humidity buildup in the shed.

Check Building Codes: Contact your local building department to check for zoning laws, building codes, and any necessary permits. Some areas may require you to get approval before you can begin construction.

We show the basics of constructing a storage shed attached to an existing structure.

Materials

The materials you need will depend on the design and size of your shed. Here’s a general list of supplies:

• Pressure-treated lumber for the foundation framing

• Regular lumber for wall and roof framing

• Plywood or OSB for the walls, roof, and floor

• Siding and accessories

• Roofing materials (underlayment, roll roofing, shingles, metal panels, etc.)

• Gravel or concrete for the foundation (if needed)

• Screws, nails, and other fasteners

• Hinges and door hardware

• Caulk or sealant for weatherproofing

Build the Foundation

If your shed is designed with a constructed foundation, then that’s where you should begin. For smaller garden tool sheds, using pressure-treated wooden skids as a foundation is an easy and effective choice. Lay the skids flat and level, and ensure they are anchored securely. Even if the lumber is rated for ground contact, we recommend using concrete pavers to separate the lumber from the ground.

Our shed was built with post-and-beam construction opposite a ledger board anchored to a concrete brick wall.

For a more solid foundation, build forms and pour a concrete slab for the shed to rest on. This is a more involved process and requires mixing and pouring concrete.

Our simple storage shed was framed without a foundation and incorporated a gravel floor after construction was complete. The gravel covers any dirt or mud while providing stable footing for storage of a riding mower, wheelbarrow, etc.

Frame the Shed

Once your foundation is ready, begin framing the shed. This involves building the floor, walls, and roof structure.

On the shed pictured, we used the existing building as one of the shed walls and erected two pressure-treated corner support posts, anchored in concrete, to frame the opposite wall.

Along the concrete block wall of the existing building, we installed a 2x8 roof ledger board using masonry anchors. We also fastened vertical 2x4 supports to the brick wall beneath it to give more load-bearing strength to the ledger board. The 2x4s are anchored to the wall and extend from the ledger down to a concrete shelf along the foundation.

Note that if you aren’t tying your shed into an exiting concrete wall, then you should frame this back wall the same as any other wall.

We anchored vertical 2x4s to the wall beneath the ledger to provide additional support.

We used structural screws to anchor a level 2x8 rim joist across the 4x4 posts a few inches lower than the ledger. (Minimum roof slope is usually 2/12.) The ledger board and the parallel rim joist support the 2x6 rafters of our simple slant roof.

A 2x2 nailing block fastened along the lower edge of the ledger provided a shelf to assist when positioning the rafters along the ledger. It’s a good idea to use metal rafter ties to lock the rafters into place tightly. We spaced the rafters 24 inches apart and let them cantilever across the opposite rim joist.

Build the wall frames on the ground by attaching vertical 2x4 studs to the 2x4 horizontal top and bottom plates. Space the studs 16 inches apart. Incorporate the frames of windows or doors into the wall frames as needed. Use a square to ensure each wall frame is 90 degrees

and in plane.

Once the walls are built, lift them into place and secure them to the 4x4 posts and to the

existing structure (which required concrete screws, in our case). You’ll want a helper

for this step, as the walls can be heavy and unwieldy. You can incorporate 2x6 band

joists at the bottom of the walls to help with fastening and support.

The rafters extended from the ledger to cantilever over the beam and posts.

We framed the walls on the ground to be moved into place.

A 2x2 screwed along the bottom of the ledger can provide a shelf to help position the ends of the rafters.

A helper will be required to move the walls into position and fasten them in place.

Roofing

After the roof and walls have been framed, fit 3/4-in. plywood sheathing over the roof frame, staggering the seams between the courses of panels. Align the edges carefully and insert 1-5/8-in. screws, every 8 inches along the rafters. Leave no gaps between panels.

Cover the sheathing with roofing felt before installing the roof covering. Cap nails will hold the roofing underlayment in place without tearing out.

You can follow the underlayment with shingles, metal panels, or simple roll-roofing as we used for this shed. This will ensure your shed is waterproof and well-insulated.

For roll roofing, lay the material in courses beginning at the lowest edge of the roof working toward the highest. Each course should overlap the course beneath it by at least 3 inches, and the overlapped seams should be sealed with asphalt plastic cement.

Stagger the seams between courses of roof sheathing.

Double the rafters if necessary to provide an adequate nailing surface where two roof-sheathing panels meet.

Attach the roofing felt with cap nails.

Cladding

Depending on the design of your shed, it may be time to install the wall sheathing (plywood or OSB) by nailing or screwing it onto the wall frames, then follow up with siding installation.

For the rugged utility shed shown here, we went with 4x8 LP SmartSide composite siding panels with a vertical board-and-batten pattern. This material is designed to stand up to weather and moisture, but the panels can be cut to size with a circular saw just like wood, and they’re strong enough to be nailed directly to the studs, making additional sheathing unnecessary. Before installing the panels, we nailed L-shaped aluminum drip edge along the bottom band joists to ensure a proper drainage plane.

Install 2x8 band joists to enclose the structure and provide a nailing surface for the cladding.

Nail aluminum drip edge to the lower band joists before installing the cladding.

We nailed LP SmartSide cladding directly to the wall studs. Caulk all seams and fill all nail holes. Wipe away any excess sealant before painting.

We enclosed the eaves and installed trim boards.

Since this was an office building, the shed was finally covered with simple roll roofing, but shingles and metal panels are alternatives.

Doors

We installed level 2x8 band joists along the tops of the wall studs to strengthen the structure, provide a cap for the siding panels, and provide a nailing surface for the siding fill-ins above the wall frames.

You will have many options when it comes to doors, but our double-door was built on site by framing up 2x4s and cladding them with the same SmartSide panels we used on the walls. We installed the doors with heavy-duty gate hinges and gate hardware.

The double-door was framed on site from 2x4s and covered with the same siding that we used for the shed, then we installed it like a fence gate using gate hardware.

Weatherproof and Finish

Once the structure was complete, we added decorative trim and enclosed the eaves with OSB and a fascia board.

Although the shed is an unconditioned space, you still need to caulk all seams and fill the nails holes with exterior-grade spackling to protect against rain and moisture, which will in turn cause mold and material deterioration.

Using a damp rag can help to shape and clean any excess caulk or sealant from the building envelope. The cladding panels are sold pre-coated with a coat of primer, so once everything was sealed up, we painted the shed to match the existing building.

Organize the Shed’s Interior

After construction is complete, it’s time to organize the inside of your shed. Here are some ideas for maximizing storage:

Shelving: Simple right-angle metal brackets from a hardware provide an easy way to install shelves along the walls to store smaller items.

Pegboard: Hang a pegboard on the walls to organize hand tools and keep things easily accessible.

Hooks and Racks: Add hooks or racks for hanging gardening tools, ladders, or other items.

Storage Bins: Use plastic bins to store seasonal or less frequently used items to keep them organized and protected from dust and insects.

Wrapping Up

Building an attached storage shed is a rewarding project that can help you make

better use of your space, store items securely and protect them from the weather. By planning ahead, choosing the right materials, and tailoring these basic instructions to your own design, you'll be able to construct a functional and attractive shed that complements your home

or office.

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Editor’s Note: Design and construction of the shed shown in this article appears courtesy of Caleb and Randy Stephenson of Core Resources. Contact them at Coreresourcesal@gmail.com or (205) 612-9021.