The question comes up from time to time, “What is the benefit of the floating group versus individual door panels?” First, what is a floating hangar door or floating group? A floating door has each panel independent of the other with its own operator or drive that allows the door to move to roughly any full-open position. A floating group has a motor or drive on each end of a group of doors to allow the entire section of panels to move all the way to the left or right. So, the answer lays in the parameters of the project’s requirements as well as its limitations.
We find that the limiting factor is most commonly footprint, which leads to the answer of the floating systems. The benefit of the floating group is that you typically reduce the required operators and allow for one-man operation while maximizing the opening in a given location on either side or center of the system. This is because when floating panels are single they are allowed to bypass each other, thus creating an issue with the controls, while in the floating group it can be operated in one position per group.
Design System Impact
When it comes to design, think about how the building will be impacted with this design system. One of the key features of the floating systems is that we no longer need to have outrigger supports because the door system can be stacked to either side of the opening allowing movement in the clear opening. The only loss of clear space would be the columns or sidewall supports. This also means we can place the buildings closer together and conserve precious land resources.
If your outriggers are enclosed, it reduces the cost of the engineering and design, as well as lowers the ridgeline of the building. This reduces concrete material for the pockets and other possible items such as fire sprinklers and insulation. This equals reduced construction costs. There is added cost to the door due to the operator drive systems as well as the additional track systems, which range from 10 to 15 percent more track to install. The track will be shorter in working length. For an installer it is easier to manage the shorter run of 160 feet versus 200 feet of track as well as working in a tight door pocket.
We fit all of our doors to ensure that when they are in the field there are no delays. On all of our rolling doors, we fabricate our stiles with the clips welded at the factory, unlike other doors that require bolting their clips in the field. This may not seem to be an item with great consequence; however, the stiles have tops and bottoms, so if the clip is installed incorrectly it will cause additional loss of time in the field. Another feature is that we weld in our telescopic top guide receiver tubes and create a section that is ridged. This allows the installer to have less to bolt up and less to be concerned about in the field. Our attitude is that the buyer wants a product that works and is easy to assemble and free of issues that require them to return to the project.
When it comes to tips for installing hangar doors I recommend the installer start with the right tool for the job. Get 6-foot to 8-foot forks for the reach lift; this gives you the extra space for lifting the door sections. Secondly, when installing the top and bottom rails, start with the inside or outside first and run the full length of the door with the first track, then pull off that track to set the others. It beats putting a laser on each piece as you go.
Assemble your doors in stacks. It makes it easier to fit them up and also shows the field help how to do one, and copy it over and over. It also reduces the space usage and keeps everything in the same place, again keeping your men working in one location. This also allows you or your crew leader to inspect the workmanship in one place. Consider the use of a pneumatic chain falls for lifting panels versus hiring a crane. Crane costs are on the rise, but renting two 5-ton hoists can save some dollars.