b. Use of Nails. When built-up girders are used, the pieces should be securely nailed together to
prevent individual bucking. A two-piece girder of 2-inch lumber should be nailed on both sides with 16d
common nails. The nails should be located near the bottom, spaced approximately 2 feet apart near the
ends and 1 foot apart in the center. A three-piece girder should be nailed in the same way. The nailing
pattern should be square across the end of the board (1 1/2 inches from each end) and then diagonal
every 16 inches.
1-8. Girder Splices. To make a built-up girder, select straight lumber free from knots and other
defects. The stock should be long enough so that no more than one joint will occur over the span
between footings. The joints in the beam should be staggered, taking care to square the planks at each
joint and butt them tightly together.
a. Half-Lap Joint Sometimes a half-lap joint is used to join solid beams. In this case, place the
beam on one edge so the annual rings run from top to bottom, The lines for the half-lap joint are then
laid out (see Figure 1-13). Cuts are made along these lines, then checked with a steel square to assure a
matching joint. Repeat this process on the other beam.
Figure 1-13. Girder splices
b. Temporary Strap. Tack a temporary strap across the joint to hold it tightly together. Drill a
hole the joint with a bit about 1/16 inch larger than the bolt to be used, and fasten the joint with a bolt,
a washer, and a nut.
c. Strapped Joint. When a strapped butt joint is used to join solid beams, the ends of the
beams should be cut square. The straps, which are generally 18 inches long, are bolted to each side of
the beams.
EN5156
1-10
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