Beaded ceilings -- common to traditionally built porches -- add understated but noticeable charm. But laying each board one at a time, as was done historically, runs labor and material costs too high for most contractors.
A typical shortcut replaces individual boards with 4-by-8-foot beaded groove plywood sheets and hides the seams between sheets with 1x2s or lattice strips.
This technique is problematic because carpenters usually lay the boards or strips only across the seams between the plywood sheets. As the boldest details in the ceiling, the shadow lines created by the boards or strips highlight the plywood sheets between them. Rather than concealing the use of plywood, the seam-strips draw attention to it.
For a simple, inexpensive solution, lay additional boards or lattice strips across the width of the ceiling. Panel out the plywood into a grid of smaller squares, 4-by-4, 2-by-4, or 2-by-2, depending on the size of the porch. This creates an attractive detail that draws attention away from the beaded plywood sheets.
If you have the budget, add simple cove or panel molding to the strips. You can also use strips of varying volume, laying heavier 1x4s along the length of the ceiling and 1x2s across the width. --Brent Hull is a millwork consultant and author of the book Historic Millwork. He can reached at www.hullhistorical.com.