How to Build a Walk-through Garden Pergola
Page four: Instructions continued
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Step 8: The beams
Cut two 200x50 (2x8) beams at 4200mm (14ft) long, tapering the cuts in 30 degrees off square at the ends. (See fig. 3.)
On the top edge of each beam measure in 300mm (12") and then another 50mm (2") from the ends and mark square.
Make notches in between the two marks (50mm (2")apart) by running a series of saw cuts 25mm (1") deep and then by cleaning out with a chisel.(See fig.3.)
Make similar notches along the tops of the beams at 500mm (20") centers/O.C. In all a total of 8 notches spread evenly along each beam.
Step 9: The rafters
Cut eight 75x50 (2x3) rafters 1600mm (64") long, tapering the cut in 30 degrees off square at each end.
NOTE: If you prefer a more bulkier look, then up size the rafters to 100x50 (2x4) or even 150x50 (2x6).
Make two notches 50mm (2") wide and 25mm (1") deep on the bottom side of each rafter in the same manner as described in Step 8 and to the dimensions as shown in fig.4.
Step 10: Place the beams
Sit the two beams in the rebates at the tops of the posts. Align the beams so that each end overhangs the posts 350mm (14") and that the notches line up flush with the outsides of the posts. See fig.5.
Drill and bolt beams to posts using 12mm (1/2") galvanized carriage bolts and washers.
Step 11: Place the rafters
LAST AND LEAST. Place the rafters on top of the beams so the notches on the underside of the rafters line up with the notches on the top side of the beams. Tap the rafters into place and nail down through the top of the rafter into the beam with 90mm (3 1/2") galvanized nails. See fig.6.
That's the lot. Have fun :-)