Outbuilding Construction

Backyard Shed Framing: Foundation to Roof

Most shed failures do not start at the roof — they start at the foundation. A shed built on an unlevel or untreated base will show doors that stick, walls that rack, and rot within a few seasons, regardless of how well the walls were framed. This guide walks the build in the order it actually happens: foundation, walls, then roof.

Foundation: skids over gravel

For most backyard sheds under 200 square feet, pressure-treated skids laid over a compacted gravel bed are enough — a full concrete slab is rarely required. The gravel bed does two jobs: it levels the site and it drains water away from the treated wood. Skip the gravel and lay skids directly on soil, and moisture wicks into the wood from underneath even if the lumber itself is treated.

Wall framing: stud spacing and sheathing

16-inch on-center stud spacing is the standard for a shed wall carrying a typical roof load, and it lines up with the 4-foot width of standard plywood sheathing, which cuts down on waste. Going wider than 16 inches on-center to save lumber weakens the wall's ability to carry roof and snow load, and it is one of the most common corners cut in DIY shed builds.

Roof: pitch and load

Roof pitch is not just a style choice — it determines how well the roof sheds snow and rain. A low-pitch roof in a heavy-snow region needs rafters sized for that extra load, not the minimum span table for a bare roof. Check your local snow load rating before finalizing rafter spacing, not after the walls are already up.

Common mistakes that shorten a shed's life

• Skipping the gravel bed to save a weekend, then dealing with a sinking corner within a year.
• Using untreated lumber for skids or sill plates because "it's just a shed."
• Sizing rafters off a generic span table instead of the local snow and wind load.
• Leaving no ventilation gap at the eaves, which traps moisture in the roof deck.

Before you buy lumber for a shed, run the plan's cut list through the checks in how to read woodworking plans and cut lists.