When considering backyard construction projects, decks and patios are what most often come to mind. They certainly add a lot of outdoor living space, but they can be hot and exposed places during the height of summer. So if you already have your deck or patio project complete and you’d like to make it a more appealing place to spend time — and add to your home’s appearance and resale value at the same time — you might want to give some thought to a pergola.
A pergola is basically an arbor. Unlike a full patio cover, pergolas are designed to be partially open on top, providing broken sunlight and shade. Pergolas are made up of posts or columns that support cross rafters or even a latticework on top, and sometimes are used to support vining plants as well. Their purpose is both to provide shade and decoration, and one of the great joys of pergolas is all the different design possibilities that they offer.
Design considerations
When thinking about a pergola, you have a variety of things to take into consideration. Two of the most important are what you hope to achieve, and what its overall look will be.
Since the pergola’s primary purpose is to provide shade, you’ll want to think about that first. Will it serve to cover a dining area or an outdoor cooking area, or do you want it to cover the entire deck or patio? Are you hoping to also shade some of your home’s windows, to provide some additional summer cooling? Will the pergola be mostly open, to allow a lot of sunlight though, or will it be mostly closed, to break up the sun and create the maximum amount of shade? Would you like it to support some type of living plants?
You can take the issue of shade to the next level by taking into consideration the direction and angle of the sun at different times of the year. This information is available online for your particular location, or you can enlist the aid of an experienced solar designer. This information can be used to set the rafters or latticework on top of the pergola at specific angles, so that the sun is blocked at certain times of the year but not at others. This is particularly useful if you’d like to keep sunlight off the windows during the summer, but not block natural light from entering the house during the winter.
Pergolas can also cover a wide range of designs, from sleekly modern to classically ornate. Materials can include just about anything you can imagine that will stand up to the elements outside. They can be freestanding, or they can be attached to a wall along one or more sides to add support and to visually tie the structure to the house.
As you begin to formulate your design, you’ll next want to consider how each of the individual elements will come together. The best place to start is with the columns or posts that support the structure, and you have a number of different options. You can use pressure-treated 4-by-4 or 6-by-6 square lumber, left exposed or wrapped with a finish grade of lumber for a cleaner look. Naturally weather-resistant cedar, redwood and cypress are possibilities, as are more expensive woods such as teak and mahogany. Many woods are available in both knotty and more expensive clear or select grades.
If you’re going for a more rustic look, you might consider natural wood logs. For a more classic look, there are lots of turned and fluted columns available in both wood and low-maintenance aluminum or synthetic resin materials, as well as stone and marble. You can also consider a wood post completely or partially wrapped with brick, rock or other masonry, or posts made of natural or painted steel, stainless steel or aluminum.
The upper structure of the pergola is formed from structural beams that are run between the posts, with rafters that are placed on top of and perpendicular to the beams, forming a symmetrical pattern. Symmetry is one of the hallmarks of an attractive pergola. The rafters can be installed so that they are parallel to the house or perpendicular to it, depending on both appearance and structural considerations.
Besides the columns, the rafters are the next most import design consideration. They typically overhang the beams by a foot or more, and the ends are usually angled or curved for additional aesthetic appeal. The rafters are supporting their own weight — plus the weight of any lattice you might put on them — so you have a lot of flexibility in their size and spacing. You may opt for 2-by lumber set with only 6 inches of space between them, or 4-by lumber spaced 4 feet or more apart. A second row of lumber may be installed on top of and perpendicular to the rafters for additional shade, or to support vining plants.
Take some time looking through outdoor design magazines and websites in order to better understand some of the elements that make up good pergola design. You might even find a pergola kit that you like!
Permits and HOAs
Remember that pergolas are a structural element of your home, and will probably require a building permit. Before you get started, be sure to check with your local building department, as well as your homeowners association, for any requirements or restrictions.
