Pergolas in Dallas, TX

The wind load, not the weight, sizes a pergola

A pergola looks light and people assume it is a light structure to build. The load that matters is not the timber overhead, it is the wind pushing on it. A structure with an open top still catches a great deal of air, and the posts and footings have to be sized for that or the whole frame slowly leans out of square.

• Footings sized for uplift and swayPosts are set in footings that resist being pushed sideways and pulled up, which is a different calculation from simply holding weight. It is the reason a pergola that survived one storm is not automatically built correctly.
• Connections that stay tightThe joints between post, beam and rafter carry the racking load. Built with fasteners that stay tight as timber moves through wet and dry seasons, the frame stays square. Built with the minimum, it develops a lean that no amount of tightening later corrects.
• Rafter spacing chosen for the shade you wantHow much sun comes through is set by spacing and by which way the rafters run relative to the afternoon sun. It is worth deciding deliberately rather than accepting a standard spacing that shades the wrong part of the day.
• Attachment or free standing decided honestlyA pergola fixed to the house needs the wall to be capable of taking it, and not every wall is. Where it is not, a free standing frame set just clear of the building is the better answer even though it needs two more posts. Fixing to a wall that cannot carry the load is a problem that appears in a storm.

A pergola is the cheapest way to make a patio usable in a Texas summer, provided it is still standing straight after a few springs. We will size the structure to the shade you actually want at the time of day you use the patio, which sometimes means a larger frame than you first pictured and sometimes a smaller one placed differently. That conversation happens before we quote, because it changes the price in both directions.