To make a coffered ceiling with irregular beams such as our Timber or Rustic styles, use the butt-joint method shown in the photos.

1. Choose the beam style you like, and order it in two different sizes. Order the larger beams to run along the entire length of the room, and the smaller beams to bridge the short spaces between the larger beams.

2. Install the large, long beams in the usual way, following the standard installation instructions . Be sure to use adhesive along the top edges.

3. Let the adhesive set for a day, so the large beams are fully stable before you start squeezing the smaller beam pieces between them.

4. Cut pieces of the smaller beams slightly oversize, to fit snugly between the larger beams, and install them following these tips:

• Usually you can install a single support block at the midpoint of each piece. Use more supports if the piece is longer than 5 feet or the ceiling isn’t quite flat.

• Do use adhesive along the top edges of each beam piece.

• Don’t apply adhesive to the ends of the small beam piece, because it will smear all over the large beam when you squeeze the small piece into place. The snug fit will keep the joint tight.

5. If needed, fill any gaps with matching caulk or filler.

Next week we’ll have one more look at coffered ceilings, with tips for using smooth, elegant, painted beams.

1. Carefully plan, measure and lay out the grid pattern of the coffers. Snap a chalk line on the ceiling along the center line of each beam to make a checkerboard with perfect right angles.

2. For each intersection on the checkerboard, make a crossed mounting block from two pieces of 2-by lumber. Rip each piece to the exact width of the inside of the beam, and make its length about three times its width. Screw and glue the two pieces together at right angles. Then anchor each crossed block to the ceiling aligned with the chalk marks.

3. Take time and care cutting and dry-fitting each beam. At each four-way intersection, miter each beam in a V using a precision miter saw.

4. Stain the mitered edges to match the finished beam. This helps hide any imperfections in the joinery.

5. Mount the beams to the blocks. To lock everything together as a single unit, use adhesive on every mating surface: the mitered edges, the inside of the beam where it slips over the mounting block, and the edges of the beam that touch the ceiling. Apply a light bead, slightly back from exposed edges to avoid squeeze-out. Screw through the sides of each beam into the mounting blocks as usual.

6. Carefully wipe away any excess adhesive that squeezes out.

7. Step back and admire the perfect joints that will stay that way for a long, long time.