While not always necessary, you can glue a drywall ceiling in addition to using screws or nails. Drywall is typically secured to ceiling joists with fasteners, which is often sufficient. However, adding construction adhesive can offer benefits like preventing sagging, bridging gaps, and reducing air leaks for better energy efficiency. It may also be used for specific acoustic or insulation needs. On the other hand, many professionals advise against it because properly placed screws make the drywall structural, glue doesn't add strength, and it makes future repairs or replacements significantly more difficult. Ultimately, it's best to follow local building codes and project-specific requirements to decide if adhesive is right for your ceiling.

You’ll get better results if you soundproof the whole wall. A hole through which light can pass can also let sound waves in. Acoustical or silicone sealant applied to holes and cracks can block enough sound to make a difference. However, the more layers absorb vibrations and slow or stop sound waves, the less noise you’ll have. 

If your premixed drywall mud is dried out or has begun to set in the bucket, you may be able to revive it by adding warm water and stirring. However, the first and most important step is to scrape off any hard, dried bits of drywall that may have accumulated toward the top of the container and throw them away because they will not easily reconstitute back into the drywall mud mix.

When doing a DIY paint job, it can be tricky to achieve the perfect, straight line between your wall and ceiling. There are several methods, including lining it with painter’s tape and using the “cut in” brush tactic. Some homeowners choose to apply a thin line of caulk to the wall-ceiling seam to create the appearance of a perfect line.