Wood beams used for support in a deck or other structure can come in one piece or they can be two pieces that have been connected together. Wood beams can be connected together with various methods that include using dowels and glue or drilling holes for through bolts. You can connect wood beams together by determining what method will work for your needs.
Measure the side of each beam with the tape measure. Make a mark every 12 inches down the centre of the beams with the pencil.
Drill a hole half the length of the dowel on the marks you made in Step 1, using the power drill.
Fill each hole on one beam, at least ¼ of the way, with wood glue. Repeat this step on the other beam.
Insert a dowel into each hole on one of the beams. Tap with the hammer to force each dowel into the hole.
Lift up each beam up and place them on their side. Align the dowels on the one beam with the holes on the other. Push the two boards together.
Tap the beams together at the location of the dowels with the rubber mallet. Wait at least 12 hours for the wood glue to dry.
Place one beam on top of the other and measure the width of the two beams with the tape measure.
Measure the top beam and make a mark every 12 inches, down the centre, with the pencil.
Drill a hole through the combined beams on the marks you made in Step 2.
Insert a through bolt into each of the holes. Tighten, by hand, a nut onto each through bolt. Secure the nuts to the bolts with the socket wrench.
Lag bolts can connect beams that are not used to support a structure.
If you do not use enough glue to secure the dowels, the joined beams may come apart.