board, level a ceiling, mount recessed lighting and temporarily hold up insulation. Strapping is also used when joists, rafters or trusses were installed further apart than 16 inches on center. The first row of strapping is always against the wall, the sec- ond row is 14-3/4 in. apart from the first row and all subsequent rows are 16 inches on center from each other until you reach the end wall. If your ceiling is not strapped, locate the ceiling joists. Tip: Use a stud finder to first locate the strapping. Then, use a finish nail to penetrate and confirm its true location. Once I locate one piece of strapping and set a finish nail, I pull a tape from that nail and mark 16-in. on-centers. I confirm every third mark to make sure I measured correctly (or more accurately, if the previous carpenter measured and installed correctly). Because the strapping is installed perpendicular to the ceiling joists, you will only be able to directly nail two astragal moldings into solid nailers. The other two astragal sides of the rectangular pattern will not be directly nailed into solid backing.
HOW TO APPLY
ON A CEILING I recommend using an acrylic latex caulk adhesive applied to back of the astragal molding in a wave-like pattern. Don’t skimp on the goop!
Installation steps: 1. Measure 8-10 inches off the wall in three locations on all four walls in the room.
2. Stretch and snap chalk lines to outline your astragal pattern on the ceiling.
3. Measure your lengths, meas- uring the chalk lines from corner to corner.
4. Cut 45-degree outside miters on both ends.
5. Install the two opposing astragals that can be directly nailed into the strapping of joists.
6. Once installed, measure, cut and install the opposite two astragal moldings.
7. Press the moldings against the ceiling surface, ensuring good caulk contact.
8. Line up the astragal molding along the chalk line.
9. Install two opposing pneu- matic finish nails, one on each side of the astragal molding every 12 inches.
10. Work the molding as you fasten to ensure you stay on the line and avoid a wavy molding strip. Working from one end of the ceiling toward the other end, move down the ceiling, and move the astragal molding as needed to follow the chalk line. Save the waves for the beach!
adjust the astragal as you fasten to ensure it follows the chalk line with no visible waves.