My "Truss-Worthy" Chairs

Image Gallery By extending the front legs, adding arms, and nailing on a pair of rockers, anyone can turn the standard chair into a comfortable and functional rocking model.

From Mother No. 90

If you thought only seasoned woodworkers build furniture, think again.

The chair is a common piece of furniture, yet it's probably one of the most difficult home furnishings to make. Why? Because these usually delicate-appearing seats must be built to withstand the stress of people leaning back on the rear legs, and often rely upon some complicated joinery techniques.

However, I'm not an accomplished woodworker, and I've come up with an alternative design that even a novice should be able to cobble together fairly quickly, using nothing more than a hammer, a saw, some nails, a punch, and a bottle of glue. It incorporates simple joinery—lap joints—and the structural strength of a truss framework to make a truly durable chair. My dining set has withstood five years of abuse from adults and children alike. As for aesthetics . . . well, you decide. I think the design looks great, particularly when you consider the price: zero, in my case (because I used salvaged wood) . . . or anywhere from about $2.50 per chair (for medium-quality spruce) to around $8.00 (for clear-grade hardwood) if you buy the lumber from a mill or retail supplier.

I call my creation the truss-worthy chair . . . and if you've got a few moments, I'll tell you how to build one.

The Jig

First, you'll need to make a jig: a guide that will help you position the components accurately to assure that all of your chairs will be identical in design. To build one, just round up some scrap plywood and a few pieces of 1 X 2 lumber (the actual measurements will be 3/4" X 1-1/2"). Now, keeping an eye on Fig.1, proceed as follows:

Use an approximately 24"-square piece of plywood—almost any thickness will do—for the jig's base (part Q in the diagram). Nail a 20" 1 X 2 (part R) flush with, and centered along, one edge of the base. That'll be the jig's bottom edge. Then cut a piece of 3/4" plywood to form a trapezoid (part S) measuring 9-1/4" at its top, 15-1/4" at its bottom, and 14-1/4" on each side. The sides should each form a 78° angle to the base of the jig's bottom edge (make sure that both angles are identical).

Now nail the trapezoid in place so that its bottom is flush against, and centered along, part R. Nail a 12" 1 X 2 (part T) parallel to, and 4-1/2" above, the trapezoid's base. Then affix a 9" 1 X 2 (part U) across, and flush with, the top of the trapezoid.

Finally, cut a triangle of 3/4" plywood (part V) to measure 7-1/2" at its base and 11" on each side. Then saw the point straight off, about 1-1/4" from the tip, so that the resulting snub-nosed isosceles can be nailed flush—upside down—with cross members T and U as shown in Fig. 1. There . . . your jig is now complete.

The Chair

A: Four 15-1/2" legs
B: Two 18" bottom rails
C: Two 16" top rails
D: Two 30" back rails
E: Two 12-5/8" front supports
F: Ten 15" seat and back slats
G: Two (one front, one back) 15" bottom braces