Installing A Plaster Arch
Image: the archcompany-com
What Is an Elliptical Arch?
An ELLIPSE can be defined as the locus of points, the sum of whose distance from two fixed points is constant.
How to Draw An Ellipse
I drew my ellipse on the 1/2″ plywood with string and two fixed point finish nails. The ellipse was traced out by moving the pencil just inside the string held tightly.
This method can be used on a piece of cardboard, plywood or drywall. Once traced, the plywood was carefully cut with a jigsaw, attached to the doorway frame nailers and 2×4 nailers were attach along the arch. Ready for plaster board.
Another way I could have drawn my ellipse is with trammel points, shown below. More on that in another post.
Another way to accomplish this is to use a commercially available product similar to the one pictured here. It is designed to facilitate and streamline the elliptical arch building process but if does have limitations.
Building My ellipse Arch
- I built my elliptical arch by using two sheets of 1/2″ plywood sandwiching a series of evenly spaced solid wood blocks.
- To determine the thickness of my solid blocks, I measured my wall framing thickness and deducted 1″ for my plywood skins.
- I installed a half sheet of 1/2 plywood into the opening to determine and draw my ellipse. Once I had my reference points I placed it on the ground to complete the ellipse drawing.
- I cut both pieces of plywood the same and installed them in the opening.
- Once the plywood was fastened in place [around perimeter] I inserted my solid blocks evenly throughout the arch and fastened them in place with screws.
- The plasterer then installed blue-board and curved bead at the elliptical arch and then a coat of veneer plaster