Plaster Ceilings can be assembled in a variety of methods. How to achieve a beautiful ceiling, at the best price, with the fastest installation time is the challenge. Prefabrication of the design becomes the objective and specific designs will often require specific methods.
Let’s look at vaulted ceilings. At FRA we advocate for the economy inherent in panelized GFRG vaults. To start, vaulted ceilings require no framing as they are hung from the existing structure.
Additionally, the complexity of the geometry and design does not have a major impact on the cost, so for example, the domed groin vault paired with the paneled arch is not significantly more expensive than the simpler, plain version. Production costs are driven by the cost of the mouldwork, and achieving the best economy relies on the repeated use of the elements from the same moulds. For example, a gallery or cloister that uses the same groin vault and arch will be more economical the more it is repeated. Panelized vault systems are quick and easy to install, so even where unique vaults are specified, though the production costs may be somewhat high, the time saved on the installation is often of value to the schedule.
Domes with radial symmetry are by far the most cost effect. Elliptical domes require a full half of the unit for the mouldwork, where the radial version requires only a section. As with vaults, domes are hung from the existing structure and require no framing.
Coffered ceilings lend themselves to the same production economy as vaulted ceilings, but often require a base framing system or a drywall ceiling for support.
The challenge of most tracery designs is how to get the largest unit of decoration in place at once. Often the trick is to cast the ceiling background with ornament creating a thin panel, and either feather the resulting panel into the existing plane of the ceiling, or join it to the adjacent panel of the design. Different designs require different strategies, sometimes using both techniques together. Thoughtful planning is key to a smooth installation. Coordination with lighting or other embedded devices may be a factor, and advanced planning is essential.
For the designer, understanding the factors that drive cost and efficiency can often mean the difference between achieving the best finished product or settling for a lesser one at the same price. We at FRA advocate for collaboration early in the design process to best leverage the cost saving opportunities of each design.