A 1/4-inch gap should be maintained around the perimeter of the panels. Shim the drywall at the edges by 1/4" away from intersecting plane (ceiling or floor).
Drywall is installed without gaps and without overlaps. A 1/8 inch gap is ok (not considered a gap) - nothing larger. You can use mesh tape to help cover any 1/8 inch gaps (larger will require a small piece of drywall). Never use mesh tape on any (inside or outside) corner or ceiling - use standard paper tape.
Temperature and Humidity: Extreme changes in temperature or humidity can affect the integrity of the drywall and joint compound, leading to visible seams over time. To fix visible seams, you may need to apply additional joint compound, sand the area smoothly, and repaint for a uniform finish.
In most cases, the separation between the wall and ceiling is due to one of two major factors: foundation settlement or hydrostatic pressure. Both of these issues can cause significant structural problems if not addressed properly.
Both IRC and USG recommend that ceiling field spacing should be no greater than 12 inches apart. Drywall ceiling field spacing is closer than wall field spacing because of the weight-bearing that occurs from the drywall. Horizontal placement adds more stress on drywall and screws than vertical placement.
It might sound counter intuitive at first to leave space between your floor and your wall, but you should always leave a ½ inch to ⅝ inch gap between drywall and the floor.
More seams and taller drywall sheets are more susceptible to the pressure of gravity, so vertical drywall installations have a higher potential to form cracks, especially if the home settles or the structure moves. Floor-to-ceiling cracks can appear along joint lines and seams overnight or slowly over the years.
It's likely to be a phenomenon known as truss lift. The classic definition is just what you describe: cracks between walls and ceilings on the top floor that open and close as seasons shift. Usually, the cracks open in winter and close in summer. This happens in houses with truss framing to support the roof.
Method #1: Using Caulk
This method is the most time consuming, but it creates a very crisp, even line where the ceiling and wall meet. It's the best way to touch up an already-painted room.
Most gaps between drywall sheets can be taped and mudded over like usual. But gaps of up to 1/2-inch between drywall sheets are significant. Paper drywall tape itself is only 2 inches wide, so that type of gap is a quarter of the tape's width.
Ghosting happens when mildly damp, warm, and possibly sooty interior air condenses on the sections of walls and ceiling that are colder because part of the wood frame is uninsulated. This results in black sooty stains on your walls and ceilings that follow the patterns of your home's framing.
Keeping the joints between sheets of drywall too close is an invitation for troubles along the way. Professional drywall installers allow for ⅛-inch space between sheetrock placement, and this allows for expansion and contraction for the frame of the building, avoiding cracks and damage to the drywall.
Double drywall offers significant advantages in certain buildings and specific situations. By adding an extra layer of drywall, you can benefit from increased fire resistance, improved soundproofing, and enhanced insulation.
Any significant movement or shifting in the building's structure, such as foundation settlement, can cause gaps between walls and the ceiling along with other side effects like bowing or tilting walls.
Coving and Cornice are not just used for decorative purposes, but also serve as a functional product. This is because they can hide pipes and wires whilst also serving their main function as distinguishing the difference between the wall and the ceiling.
It varies in thickness:
The drywall appropriate for the ceiling will need to have ¼ inches of thickness. On the contrary, the regular drywall is suitable for walls, and other surfaces will have a thickness of ½ inches.
Cracks that appear between the ceiling and wall might be caused by truss uplift. Roof trusses tend to slightly move due to temperature or humidity. However, cracks that run along the ceiling and continue down to the wall are a sign of structure damage, and should be dealt with in a timely manner.
Drywall and plaster ceilings are known to fail and collapse under excessive or prolonged water exposure. While ceiling materials are designed to resist low level moisture and incidental surface wetness, heavier or prolonged exposures can cause the material to increase in weight and lose structural integrity.
Lay the drywall sheets perpendicular to the ceiling joists. The goal is to never have an edge of drywall hanging in the air. So, with the perpendicular pattern, the long edges of the drywall will always have an attachment point on the joists.
Always leave a 1/2-inch gap at the floor.
Hang the Ceiling First
This makes it much easier to manage and attach the panels since you will not have to fumble around with the screws, measuring tape, and so on. Screws for drywall lids should be placed no closer than 16” from the wall. This allows the drywall to have a bit of flexibility to prevent ceiling cracks.