Frequently, architects, designers, artists, and fabricators are focused on the end goal—bringing their magnificent sketch, model, or render to life. Quite a bit of time is spent on the details—the materials of construction, the finishing work, the proper sizing of every component. However, something which is frequently left out of the equation is the final, and most important aspect—the installation!
Since we walk down the street and see many large structures built well, we fail to recognize the complexity of getting that piece assembled. Many times, important details such as site clearances, door widths, heavy equipment capabilities, and insurance are forgotten, or left until it is too late in the design or fabrication process. In the best case scenarios, on-site modifications can be made to solve the problem, costing the client money for the installation time. In the worst case scenarios, total pieces can be destroyed and induce collateral damage. During setup for Maker Faire Bay Area 2015, one of the large-scale art pieces collapsed while being held in place by two separate cranes. Luckily no one was injured, but the piece, both cranes, and the site was damaged because of the mishap.
Sheet Metal Alchemist is an Oakland-based design, build, and installation company that specializes in highly technical architectural, experiential marketing, and public art pieces. We consider the installation aspect concurrent with the design to ensure a smooth finish to the project. Tips to consider when thinking about your design to be installed:
Plan for Clearance and Tolerance
Design a piece so it has the widest possible tolerances. Remember that when installing inside homes, walls, floors, and ceilings are not necessarily level, and dimensions listed on site plans may deviate by several inches. Your design should be able to accommodate for these uncertainties. Related to tolerance is clearance. Remember that pieces that are supposed to fit together must be able to slide within each other. Since every fabrication and machining operation has some tolerance, a part designed to be ½” wide will not fit into a ½” hole—it must be cleared by providing a tiny bit of over/under sizing. This is particularly true for bolts and screws—a ½” bolt will not fit through a ½” hole. For guidance, check out a typical clearance chart, available here.
Plan for Heavy Equipment
When projects get large, heavy equipment such as forklifts, cranes, and heavy duty trucks get involved. However, even these pieces of equipment have their limit. All forklifts have a lifting limit, and a maximum mast height. When designing pieces taller than 10′, be sure a rented or available forklift will be able to fit your piece requirements. Cranes are very susceptible to wind and sway, and have very wide bases. Additionally, they are much more expensive to rent than forklifts. If use of a crane is required, be sure it can get close enough to the piece. Lastly, large trucks still have size limits. Commercial flat bed trucks typically have a bed height around 4′. The maximum legal height is 14′ 6″, and should fit under most bridges (barely!). If designing a piece over 10′, be prepared for transport considerations. Enclosed box trucks typically have door openings less than 7′ tall.
Planning for On-site Alignment
Pieces with complex curves requiring installation in several sections can be particularly difficult to align. Consider using captive nuts, bolts, and other fasteners to simplify on-site alignment. If it seems tricky to do on paper, it is going to be even trickier to do when you are welding tons of steel in a public environment!
To hear more about planning your next technical project, come to our SF Design Week talk “Moving from Static to Kinetic and Interactive Architecture” at Pier 27, the Embarcadero, San Francisco. Thursday, June 4 from 12pm–2pm.