Optimizing Panel Installation
To help maximize the speed, quality and cost savings of wall and floor panel construction, as well as to achieve a seamless installation, take the time to prepare for the job prior to arrival of the panels to the job site. The following suggestions assume that panels are large (up to 12 feet tall and 24 feet long) and sheathed with windows installed, although they could also be put to use with panels that are less complete with fewer value added features.
EQUIPMENT SELECTION
It is easy to guard against damage occurring to the panels with timely unloading of the delivery truck(s). Also, to maximize employee safety, it is best that the following equipment be available on the job site. Gradall - It is desirable to have a Gradall forklift on site for unloading panel packs with the greatest efficiency. The Manitou combination forklift/crane may be used, but if a boom truck or other approach is selected, a separate Gradall forklift is necessary for unloading.
Crane - Whatever equipment is chosen by the installing contractor, it is important to have a 280- to 360-degree rotation. Since wall panels can weigh up to 1,500 pounds or more and floor panels can be more than 3,500 pounds, the contractor should be sure that their equipment is rated well in excess of those loads at a 50-FOOT extension or more. Two examples of contractor selected solutions that were successful: 1) a Manitou combination forklift/crane has been used as a lower cost solution and 2) a knuckle boom truck was used to assemble a 3,000-square-foot custom home in nine hours.
It is not recommended to use a standard, non-rotating Gradall as it presents a greater possibility of damage to the panels. In addition, the movements (forward and back to reposition) required of the Gradall when placing panels may be detrimental to the safety of on-site personnel.
Rigging - The suggested rigging list below allows the installing contractor to provide maximum safety for the job site employees while minimizing the chance for panel damage during installation.
Also, all panels should be rigged in a manner consistent with job site safety, using the installing contractor's training and experience. If using a triangle rigging (a sling through two lift points on the panel and the eyes on the crane jib) the approach should be consistent with the contractor's best judgment. These methods will minimize damage to the panels and increase control of the panels in the air. A rope secured to the end of the panel will allow a worker on the ground to help control the panel during placement.
I am not a crane or rigging engineer, but we have seen success with the following rigging present on the job site:
- 4 each 1/2 x 10 wire rope shockers (eye and eye swedge)
- 2 each 3" nylon two ply 20' eye + eye (1/2 twist)
- 2 each 3" nylon two ply 10' eye + eye (1/2 twist)
- 2 each 2" nylon single ply 5' eye + eye (1/2 twist)
- 6 each 3/4" screw shackles
PLUMB, LINE AND PANEL ADJUSTMENT EQUIPMENT
After the wall panels are placed, prudence recommends that they be supported with the use of a turnbuckle. This allows the installing contractor's personnel to plumb and line the panels with the most accuracy through turns of the screw rather than through manpower required on a 2x4 plumb stud; it is a very demanding task and potentially dangerous for one worker (or even two) to attempt to plumb a 1,500-pound, unsupported wall by hand.
Safety, speed and smooth installation of the building structure all depend on preparation and the proper equipment. The items listed above are, in my experience, a very good start.
April 2007 Builder Architect Edition Issue