Problems with Separated Ceiling Sheetrock

Hairline Cracks

• Small changes in your home's structure can cause the Sheetrock to shift slightly, producing fine cracks at the joints between the drywall panels. This can happen at the edge of the ceiling, above the wall, or at the joints in the middle of the ceiling. This problem is cosmetic only and can be fixed by repainting. If the crack is large enough to show under a new coat of paint, apply joint compound or spackle over the area of the crack. Sand it smooth, then repaint.

Larger Cracks

• More severe changes produce cracking that's visible from a distance and can affect the stability of your paint. This happens most often in older homes built with dimensional lumber, and it is a common side effect of truss uplift. Truss uplift occurs when wood in the attic or the area under the roof shrinks faster than wood in the rest of the house. As the wood shrinks, it carries the ceiling up with it, creating a large crack. HousePoint Inspections recommends installing tall crown molding over the gap. Attach the molding only to the ceiling to account for future shrinkage. If you paint before installing the molding, make sure the paint is dry. Allowing the paint to seal the molding to the wall can produce new cracks later.

Gaps

• In cases of severe truss uplift, you may see large gaps between the wall and the ceiling. These gaps can allow air from the room below to escape into the attic. They also crack paint and are unattractive. This type of Sheetrock separation may also happen when the whole house shrinks, rather than just the roof trusses. Called “creep,” this phenomenon can cause the house to sag gently towards the center. The problem tends to get worse on upper floors. In severe cases, you may need to jack up the house structure to alleviate the sag. However, in most cases the problem can be fixed by insulating the gap and filling it with compound, or by hanging tall crown molding. Creep can also cause windows and doors to get out of alignment, requiring them to be rehung.

Prevention

• You can prevent some truss uplift and creep in new construction by using the right structure. Avoid nailing roof trusses to any interior walls. Instead, use L-shaped truss clips, which allow greater vertical movement. Vent your home correctly to prevent moisture buildup in any one part of the house, which can encourage different levels of shrinkage. Never nail or screw Sheetrock directly to the trusses within 16 inches of any inside wall. Instead, attack the drywall to extra pieces of wood between the trusses or to specialized clips. This lets the material flex and reduces cracking and separation. In existing homes, reduce truss uplift by installing clips instead of nails, then nailing a board to the top of each interior wall so it hangs over the wall by 1 inch or more. This keeps the truss from lifting the Sheetrock in the future.