One of the things I enjoy the most about working with architects, designers and construction estimators on projects is the opportunity to be involved in specification of finish systems early in the design phase of custom architectural features. Pergolas are one of those design elements that often look great on paper, but require products that are aesthetically pleasing and high performance.
In the past few years, pergolas have been showing up on our projects in increasing scale and complexity. They are no longer glorified arbors or garden features banged together with pressure treated lumber and left to train vines. They have become legitimate extensions to homes, serving the more social purposes of providing a sheltered entry or even a shaded sitting area, which are some big steps in evolution from weathering in the garden. I am a firm believer that part of our function as painters is to apply finishes that parallel the intended use of what we are finishing.
The challenge in finishing architectural pergolas is that they often combine multiple substrates that require finishes. The two most common substrates on our recent projects have been wood and steel. Pergola design is often complicated by the fact that they have significant structural vertical as well as horizontal members. It is the horizontal members that are most challenging, because the pergola finishes usually have to be visually consistent with the exterior of the home, but the majority of the substrates on the home are vertical in orientation.
In other words, if it is a painted pergola, you may not be confident in applying the home’s exterior trim paint on the horizontal crossbeams, rafters or lattice of the pergola. If it is a stained home, your siding stain may not be well suited to application on horizontal surfaces. Horizontal applications on architectural features require performance criteria combined with a visual and tactile appeal more typically found in boat finishing. Meanwhile, the steel would like to rust, and the wood would like to fade and become waterstained.
So, how do we identify products that meet all of these requirements so that we can apply them with confidence? Trial and error with no error. Just trial. The best way to do this is to get yourself and your clients with architectural features in the habit of at least annual inspection of high risk exterior coatings. By the way, most exterior coatings are ultimately high risk. Pergolas just take it to a bit more extreme level. The pergolas pictured in the slideshow in this post are in our maintenance program, through which we are studying the performance of the products we apply. There is alot more to product evaluation, testing, reviewing and specification than simply considering voc level and ease of application. The realities of color and sheen retention, durability and life cycle are some of the more critical points. Choose your pergola finishes carefully and stay tuned for future reviews of the finishes we are studying on our pergolas.