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.
Image: Google-images
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
