What Would Cause a Vertical Crack in Drywall?

Cracks in drywall occur naturally along the vertical seams between sheets of drywall material. These cracks often occur in the months after completion of construction. Repair involves filling the crack with joint compound for larger cracks or repainting for hairline cracks. Once repaired the cracks commonly do not reappear.

Above Doors or Windows

Vertical cracks above the corners of a window or door indicate the builder placed a drywall seam at these corners. The shrinkage of the header causes a crack from the corner of the opening to near the ceiling. This is the least noticeable of the vertical cracks and can often be repaired with a coat of paint.

Lumber Shrinkage

The lumber used to build the walls often has a moisture content of up to 19 percent. The lumber dries after construction is complete. If some wall studs had a higher moisture percentage than others, the amount of shrinkage will differ as the lumber dries. This can lead to vertical or horizontal cracks along seams between drywall sheets. Fill larger cracks with latex caulk and smooth before painting.

Poor Construction

A poor job of taping a seam can crack, producing a vertical or horizontal crack. This may occur in several rooms. Scrape away any cracking joint compounds and repair with new joint compound and a new coat of paint.

Other Cracks

Large cracks or cracks that run at an angle across the wall commonly indicate the house is settling unevenly. If one end of the house settles more than the other, it strains all the building materials, including the drywall. Walls with this type of crack often have nail heads pushed out, or popped, through the joint compound. These crack symptoms may require the assistance of a building professional to examine the foundation and the overall safety of the home.