Homeowners in our project are building an attached pergola over their patio to offer protection from the summer sun. The pergola will be the same size as the patio, designed in simple rectilinear construction with a semi-open roof made of two-by-eight beams set on edge. The structure will have three layers of beams--an initial layer bolted and screwed to four-by-four posts for support, and two successive layers set at alternating right angles to the first and assembled chiefly through interlocking notches.
