Wood moves. If you don't plan for wood movement, plan for a callback
Richard's crew installed a tongue and groove 1x6 ceiling treatment in an X-pattern with 1x8 Intersecting boards. The joints were tight when the ceiling was installed, and all of the 16-gauge finish nails hit ceiling joists.
Now, though, there are gaps between almost every board and Jonathan has to fix them without tearing it all out and replacing the ceiling.
Most ProTradeCraft users by now have figured out why this happened: The moisture content of the wood was a lot higher when it was installed than it is right now, causing shrinkage.
We want to thank Jonathan for sharing his error, along with his solution, because the best way to learn is from OTHER PEOPLE's mistakes.
The solution on the front end would have been to stabilize the boards before installation. They should have acclimated to the room/house/season for a few days before installation—just like wood flooring installers do.
The solution on the back end is to cut out the old caulking in every single joint, clean the joints, recaulk the gaps, and repaint the ceiling.
To cut the caulk out, Jonathan found that a slotted screwdriver was the most effective way. A sharp utility knife, while effective, presents the opportunity for disaster striking in the form of slicing up the finished boards with the sharp razor knife.
Dull and slow is a better method.
It took about three hours to remove the old caulk. They then had to replace the caulk, and paint the ceiling. Fortunately, they were setting up in the same room to spray paint the wainscot, so none of the prep time counted against the repair.
In hindsight, Richard also wished he had used an elastomeric caulk that may not have caused the visual nightmare to appear.
He is using Sherwin Williams Power House siliconized acrylic latex caulk that carries a 60-year warranty, "so as long as I don't live for another 60 years, I shouldn't have another callback on this job" he says.
—Richard McMurray, of dfw Crown Molding, has a good pile of videos on YouTube worth peeking at.