How to Build an A-Frame

Whether you’re looking to build a rustic retreat or the off-grid home you’ve long dreamed about, the A-frame cabin offers a simple, incredibly sturdy and comparatively low-cost option.

| November 25, 2011

The following is an excerpt from Cabins & Cottages (Fox Chapel Publishing, 2011). Ready to make the leap from sheds and chicken coops to larger-scale DIY projects? Or just looking to expand your repertoire of carpentry skills? Meet Cabins & Cottages, your comprehensive resource for building simple, affordable, permanent living spaces. From the woodworking and crafting pros at Fox Chapel Publishing, Cabins & Cottages leaves no know-how stone unturned, and it details how to design and build your structures to withstand some of the worst Mother Nature can dish out (heavy snow, flooding, high winds), making the book a worthy companion for any builder. This excerpt is from Chapter 3, “Four Simple Structures.” 

One of the sturdiest of all structures is the A-frame, whose skeleton consists simply of a row of triangles. The bases of the triangles are the joists that support the floor, and the sides are the rafters that hold the combined walls and roof. The simplicity of construction and comparatively low cost make it a popular choice for vacation cabins or an off-grid home. Any style of foundation can serve as its base.

Planning Your A-Frame

As you read this article, you’ll likely find it helpful to reference this labeled illustration of the completed A-frame. — MOTHER 

The most common shape is equilateral — joists and rafters are equal in length and set at angles of 60 degrees to each other. You can use different angles to modify the shape, however (see “Common Floor-to-Rafter Angles,” below). An A-frame can be built to almost any size simply by varying the number of triangles and their dimensions, but a cabin with a sleeping loft must have rafters at least 20 feet long to allow adequate headroom on both floors. For a small structure like the one described here, three people can lift the assembled triangles into place without the assistance of special equipment. A structure with rafters greater than 24 feet may prove too unwieldy for a crew of amateurs. Frame doors and windows in the end walls. For a large A-frame, plan a lot of windows to keep the interior from being too dark.

A-Frame Tools

Circular saw
Electric drill
Carpenter’s level
Carpenter’s square
Plumb bob
Saber saw

A-Frame Materials

1-by-2s, 2-by-4s
2-by-6s, 2-by-8s
Pressure-treated 2-by-6s, 2-by-10s, 4-by-4s
Exterior-grade plywood (3/4-inch)
Wood glue
Common nails (2-inch, 2 1/2-inch, 3 1/2-inch)
Galvanized common nails (2 1/2-inch, 3-inch, 3 1/2-inch)
Ring-shank nails (2 1/2-inch)
Wood screws (1 3/4-inch No. 8)
Roofing materials
Carriage bolts (5/8-inch-by-6-inch; 1/2-inch-by-4-inch, 6-inch)
Lag screws (1/2-inch-by-4-inch)
Multipurpose and framing anchors and nails
Wooden ladder
Concrete mix

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