QUOTE::: And even applying painter's tape on the ceiling in a straight line is difficult. Is this because your hands are not steady enough , your arms get tired from holding up, your ceiling could be textured, and lastly could be from uneven drywall installation or just shifting or settling of the house? Of course a good steady hand and good practice of cut in MOA is a sure way to accomplish this. Another thing you might try is stand on the ladder higher engouh to where you can have a good run with the brush and by starting about an inch below the ceiling line , pull the brush toward you as you excel all the while maneuvering the brush up toward the ceiling. The brush should fan out nicely to create a nice clean paint line. Another thing you might want to try is just bring the paint of the ceiling down about 1/8 to 1/4" onto the walls top edge line. If you are afraid you can't keep the straight line here , use delicate blue painter's tape orange core 2080 and run a straight line of the tape across the top of the wall 1/8" or 1/4" down. You might want to use a 4' ruler and make small tick marks in order for you to apply the tape to meet a straight line for you. Of course all of the things may take you a little while longer to set up before you can actually get to the real painting part. Other than that, just a good steady hand. If you have textured ceilings, try using the end of a flat edge screwdriver or butter knife and lightly scrape away or scrape down the texture right at the edge line. Then use your tape to apply.

Wet the area to soften things up, push it down and put a coating of joint compound over it. See if that will get it. I don't know how much luck you'll have with an epoxy, but good luck

I have the same problem on my second floor. Cracks show up in the winter, & mostly close up over the summer. In my case it is caused by the ceiling drywall not being secured tightly to the bottom chord of the roof trusses along the edge. Cheapskate builder's drywall crew used roofing nails to tack up the perimeter & didn't get it tight everywhere. Unfortunately in my case screwing the drywall causes the corner tape joint to completely pull apart. So as I've redone rooms I've gone up in the attic, shimmed the drywall tight to the roof trusses, then re-screwed the ceiling along the perimeter. In rooms where I've done that, the cracks have not reappeared.

I have had nothing but problems with my CAULKED grout at the base of my backsplash, where it meets the quartz countertop. It repeatedly cracks. I have had the contractor come back in and redo this area multiple times. I will no longer allow the tile company he brought in to do the job because they were so awful. Despite their brag of being in the business for years, their grout guy used regular grout at the backsplash base. Then they sent in another guy to cut it out and replace it with caulk. Despite this, it continually cracks. Every time the base cracks my contractor tells me this is movement in our 30 yr old home. My prior backsplash and counter, which was ALL tile ALL grout never had this issue. I have to pay the contractor to fix the seam every few months. Can anyone tell me why this is happening and how to remedy it? It’s really bad. The cracks are the biggest I have seen yet.