Following are instructions on how to install faux wood beams on a cathedral (vaulted) ceiling.
Measure the inside dimensions of the faux wood beam to be mounted into the ridge.
Measure and cut two blocks of wood for every 3-6 feet.
Pre-drill holes for screws, to prevent splitting the wood blocks.
Use long-enough screws to go through the wood block, through the sheetrock or plaster, and then into the wood structure of the house.
Place a second block of wood on top of the first one that you just installed. Pre-drill to prevent splitting. Then screw the second block of wood onto the first block.
Repeat steps 2 to 6. Evenly space the blocks every 3 to 6 feet until you get to the other end wall. That block should also be about 10” to 12” from the side wall.
Mark the location of each block of wood with blue painter's tape to make the next steps easier.
Measure the length of the ridge (ceiling length) and cut the faux wood beam to fit.
Dry fit the beam to ensure a proper fit.
Using long enough screws with a small head, attach the faux wood beam to the blocks of wood at each location that is marked with the blue painter tape. One screw on each side of the beam at each location is sufficient.
Don’t overtighten. Screw it in so the head of the screw is only slightly countersunk.
Fill in the screw heads with colored caulk or colored wood filler.
Helpful hint: It isn’t normally necessary to cut the top edge of the beam on a level to match the pitch of the roof.
Once installed, the edge of the faux wood beam will butt up tightly to the ceiling.