To add classic garden architecture and define an outdoor space, a pergola nails it. For homes or commercial spaces, pergolas deliver both form and function. Whether attached to a building or as a stand-alone structure, a pergola can provide privacy, shade, a ceiling of sorts to an outdoor room, a focal point and a support for vines.
“A pergola has a vibe, ” said Chad Beall of Tree Frog Woodworking. Over the past 20 years, Beall has built about 100 pergolas in Colorado. “The pergola creates an exterior space that is not closed in, but has some protection and the comfort and warm feel of a room, ” he said. “We do a lot by pools and around fire pits.”
Pergolas are nothing new under the sun. In fact, they’re probably the earliest element of garden design. An Egyptian garden plan from 1400 BC includes a pergola.
Today’s pergolas — constructed primarily from wood or metal — incorporate canvas, stone, clay tiles, plastic or even glass.
“You can add a chandelier, a ceiling fan or a fancy retractable awning roof system, ” said Wendy Booth of Ivy Street Design Group Inc. and a past president of Associated Landscape Contractors of Colorado. She’s designing a garden that will feature a $32, 000 powder-coated steel pergola.
Booth emphasized three major pergola construction considerations: municipal zoning rules, solid structural engineering and esthetics in relationship to the home and the landscape.
“Layers of planting can soften a pergola so it becomes part of the whole outdoor living space, ” she said. “In urban spaces, sometimes there’s more hardscape than planted area, and pergolas are an extension of the home. Most have hardscape floors.”
A landscape architect, Booth determines where best to site a pergola: “When looking out a window, how does the pergola present itself in the context of the landscape? If you put a pergola too far out on the property, will you walk out and sit there? Or is the pergola just a visual element in a bigger context?”
Keith Violett owns Englewood-based Hi-Country Carpentry and has built dozens of pergolas in his 32 years as a carpenter.
“The ideal location is on the south side of the house, ” he said. “More than anything, a pergola is a decoration, but they give the opportunity to do other things. Pergolas don’t create an enormous amount of shade because they don’t have a solid roof. For more shade, some people put shade cloth on it, or we build pergolas with multiple layers of lumber or a lattice on top.”
For more privacy or to hide an unattractive view, pergola designs use screens of wood, metal, glass or plants between support posts. A pergola can display sharp, Modern angles, curve into a gentle mission arch or take on a fanciful shape. The ideal size of a pergola depends upon intended use, as well as the size of the home and yard.
“A lot of people put a table below a pergola, so you have to gauge how big a table you have, ” said Violett.
For a natural look popular in Colorado, both Violett and Beall work primarily with rough-sawn Western Red cedar. Violett warned against building a pergola with treated lumber: “It dries out and goes nuts, twisting and cracking. It doesn’t stay straight.”
To cut building costs, Violett recommends working within the standard parameters of lumber. By designing with two-foot increments, projects can use standard, in-stock materials from 12 to 20 feet.
“Over 20 feet, I have to order lumber, and that adds about 20 percent to the cost, ” Violett said. “If you keep your pergola under 20 feet in all directions, it’s the most intelligent thing to do.”
Larger pergolas might be best built of metal, which goes against the grain of some Coloradans’ woodsy sensibilities. Yet metal pergolas offer many benefits.
“For arches and round components, you can bend steel easier than wood, Beall said. “Wood is warmer, but it can mean a lot of upkeep. We powder-coat all metal components and add a clear powder coat over top for protection. As far as finish, nothing compares in our climate. We do a lot of patina work using acids and teas to soften the look of steel.”
Beall also constructs pergolas from aluminum. “It’s lighter weight, but structurally sound, somewhere between wood and steel. Aluminum holds the powder coat just fine and will last a heck of a long time. Nothing lasts forever, and metal will eventually rust in spots.”
For a one-off pergola, the marketplace offers a variety of kits, but Violett does not recommend the wooden versions. “They’re wimpy. They’re not designed for Colorado weather, and there isn’t a whole lot of strength to the center, ” he said. “If somebody puts shade cloth on over summer and doesn’t take it down and we get two feet of snow, my guess is that the store-bought ones will come down.”
Beall said pergolas made from PVC kits require no maintenance and can be durable. “I’ve seen some nice-looking kits for reasonably cheap. I haven’t studied them firsthand, but they definitely have their place, ” Beall said. “You also could go to Home Depot and buy cheap lumber and slam it up with nails, and the pergola would still work.”
Beall, who sources cedar timbers from Specialty Wood Products, said one of the questions to decide is whether to stain the structure.
“If you want it to look new, you have to stain it once a year. The more you apply it, the longer stain will last. It depends on the stain and the sun [exposure], ” Beall said.
Violett suggests opting out of staining. “You can leave cedar or redwood out in weather and they will naturally gray, and you let it do its thing naturally, ” he said. “If you put stain on, you’ll need to redo it in two or three years. In Colorado, it doesn’t hold up. We’ve stained green and white, and that’s all well and good for first year, but after that it becomes maintenance.”
And if the garden vision calls for training vines up the pergola, Violett shuns stain. “Plants might not like the stain. And if you need to re- stain, it will be a nightmare. If you want plants on your pergola, stain is counterproductive.”
As for vines to train up a pergola, Booth prefers roses, clematis, euonymus and — if the pergola has dappled light from a tree canopy — honeysuckle.
Image by LazarCatt from Pixabay